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digitalmars.D - A method for enum2str conversions. Reactions?

reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
Just thought I'd share what I came up with for the enum => string stuff, 
which is currently resident in std/openrj.d. If it receives a +ve 
reaction we can move it into somewhere common, and use it for all enums. 
(That's assuming, of course, we don't get something in the language to 
do it for us.)

Let me know what you think.

    private struct EnumString
    {
        int     value;
        char[]  str;
    };

    private template enum_to_string(T)
    {
        char[] enum_to_string(EnumString[] strings, T t)
        {
            // 'Optimised' search.
            //
            // Since many enums start at 0 and are contiguously ordered, 
it's quite
            // likely that the value will equal the index. If it does, 
we can just
            // return the string from that index.
            int index   =   cast(int)(t);

            if( index >= 0 &&
                index < strings.length &&
                strings[index].value == index)
            {
                return strings[index].str;
            }

            // Otherwise, just do a linear search
            foreach(EnumString s; strings)
            {
                if(cast(int)(t) == s.value)
                {
                    return s.str;
                }
            }

            return "<unknown>";
        }
    }

    /* 
/////////////////////////////////////////////////////////////////////////////
     * Enumerations
     */

    /** Flags that moderate the creation of Databases */
    public enum ORJ_FLAG
    {
            ORDER_FIELDS                    =   0x0001  /*!< Arranges 
the fields in alphabetical order                  */
        ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes 
blank records to be ignored                         */
    }

    public char[] toString(ORJ_FLAG f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the 
fields in alphabetical order" }
            ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank 
records to be ignored"        }
        ];

        return enum_to_string!(ORJ_FLAG)(strings, f);
    }

    /** General error codes */
    public enum ORJRC
    {
            SUCCESS                      =   0          /*!< Operation 
was successful                                   */
        ,   CANNOT_OPEN_JAR_FILE                        /*!< The given 
file does not exist, or cannot be accessed       */
        ,   NO_RECORDS                                  /*!< The 
database file contained no records                     */
        ,   OUT_OF_MEMORY                               /*!< The API 
suffered memory exhaustion                         */
        ,   BAD_FILE_READ                               /*!< A read 
operation failed                                    */
        ,   PARSE_ERROR                                 /*!< Parsing of 
the database file failed due to a syntax error  */
        ,   INVALID_INDEX                               /*!< An invalid 
index was specified                             */
        ,   UNEXPECTED                                  /*!< An 
unexpected condition was encountered                    */
        ,   INVALID_CONTENT                             /*!< The 
database file contained invalid content                */
    }

    public char[] toString(ORJRC f)
    {
        const EnumString    strings[] =
        [
                {   ORJRC.SUCCESS,              "Operation was 
successful"                                      }
            ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file does not 
exist, or cannot be accessed"          }
            ,   {   ORJRC.NO_RECORDS,           "The database file 
contained no records"                        }
            ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered memory 
exhaustion"                            }
            ,   {   ORJRC.BAD_FILE_READ,        "A read operation 
failed"                                       }
            ,   {   ORJRC.PARSE_ERROR,          "Parsing of the database 
file failed due to a syntax error"     }
            ,   {   ORJRC.INVALID_INDEX,        "An invalid index was 
specified"                                }
            ,   {   ORJRC.UNEXPECTED,           "An unexpected condition 
was encountered"                       }
            ,   {   ORJRC.INVALID_CONTENT,      "The database file 
contained invalid content"                   }
        ];

        return enum_to_string!(ORJRC)(strings, f);
    }

    /** Parsing error codes */
    public enum ORJ_PARSE_ERROR
    {
            SUCCESS                         =   0       /*!< Parsing was 
successful                                                         */
        ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A record 
separator was encountered during a content line continuation          */
        ,   UNFINISHED_LINE                             /*!< The last 
line in the database was not terminated by a line-feed                */
        ,   UNFINISHED_FIELD                            /*!< The last 
field in the database file was not terminated by a record separator   */
        ,   UNFINISHED_RECORD                           /*!< The last 
record in the database file was not terminated by a record separator  */
    }

    public char[] toString(ORJ_PARSE_ERROR f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_PARSE_ERROR.SUCCESS, 
"Parsing was 
            }
            ,   {   ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, 
"A record separator was encountered during a content line 
tion"         }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, 
"The last line in the database was not terminated by a 
           }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, 
"The last field in the database file was not terminated by a record 
separator"  }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, 
"The last record in the database file was not terminated by a record 
separator" }
        ];

        return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
    }
Mar 09 2005
next sibling parent reply "Andrew Fedoniouk" <news terrainformatica.com> writes:
Matthew, could you attach this as  d source file?
Beg my pardon, but it is hardly readable.

Thanks in advance,

Andrew Fedoniouk.


"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message 
news:d0oiuc$13r3$1 digitaldaemon.com...
 Just thought I'd share what I came up with for the enum => string stuff, 
 which is currently resident in std/openrj.d. If it receives a +ve reaction 
 we can move it into somewhere common, and use it for all enums. (That's 
 assuming, of course, we don't get something in the language to do it for 
 us.)

 Let me know what you think.

    private struct EnumString
    {
        int     value;
        char[]  str;
    };

    private template enum_to_string(T)
    {
        char[] enum_to_string(EnumString[] strings, T t)
        {
            // 'Optimised' search.
            //
            // Since many enums start at 0 and are contiguously ordered, 
 it's quite
            // likely that the value will equal the index. If it does, we 
 can just
            // return the string from that index.
            int index   =   cast(int)(t);

            if( index >= 0 &&
                index < strings.length &&
                strings[index].value == index)
            {
                return strings[index].str;
            }

            // Otherwise, just do a linear search
            foreach(EnumString s; strings)
            {
                if(cast(int)(t) == s.value)
                {
                    return s.str;
                }
            }

            return "<unknown>";
        }
    }

    /* 
 /////////////////////////////////////////////////////////////////////////////
     * Enumerations
     */

    /** Flags that moderate the creation of Databases */
    public enum ORJ_FLAG
    {
            ORDER_FIELDS                    =   0x0001  /*!< Arranges the 
 fields in alphabetical order                  */
        ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes blank 
 records to be ignored                         */
    }

    public char[] toString(ORJ_FLAG f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the fields 
 in alphabetical order" }
            ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank records 
 to be ignored"        }
        ];

        return enum_to_string!(ORJ_FLAG)(strings, f);
    }

    /** General error codes */
    public enum ORJRC
    {
            SUCCESS                      =   0          /*!< Operation was 
 successful                                   */
        ,   CANNOT_OPEN_JAR_FILE                        /*!< The given file 
 does not exist, or cannot be accessed       */
        ,   NO_RECORDS                                  /*!< The database 
 file contained no records                     */
        ,   OUT_OF_MEMORY                               /*!< The API 
 suffered memory exhaustion                         */
        ,   BAD_FILE_READ                               /*!< A read 
 operation failed                                    */
        ,   PARSE_ERROR                                 /*!< Parsing of the 
 database file failed due to a syntax error  */
        ,   INVALID_INDEX                               /*!< An invalid 
 index was specified                             */
        ,   UNEXPECTED                                  /*!< An unexpected 
 condition was encountered                    */
        ,   INVALID_CONTENT                             /*!< The database 
 file contained invalid content                */
    }

    public char[] toString(ORJRC f)
    {
        const EnumString    strings[] =
        [
                {   ORJRC.SUCCESS,              "Operation was 
             }
            ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file does not 
 exist, or cannot be accessed"          }
            ,   {   ORJRC.NO_RECORDS,           "The database file 
 contained no records"                        }
            ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered memory 
 exhaustion"                            }
            ,   {   ORJRC.BAD_FILE_READ,        "A read operation 
         }
            ,   {   ORJRC.PARSE_ERROR,          "Parsing of the database 
 file failed due to a syntax error"     }
            ,   {   ORJRC.INVALID_INDEX,        "An invalid index was 
 specified"                                }
            ,   {   ORJRC.UNEXPECTED,           "An unexpected condition 
 was encountered"                       }
            ,   {   ORJRC.INVALID_CONTENT,      "The database file 
 contained invalid content"                   }
        ];

        return enum_to_string!(ORJRC)(strings, f);
    }

    /** Parsing error codes */
    public enum ORJ_PARSE_ERROR
    {
            SUCCESS                         =   0       /*!< Parsing was 
 successful                                                         */
        ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A record 
 separator was encountered during a content line continuation          */
        ,   UNFINISHED_LINE                             /*!< The last line 
 in the database was not terminated by a line-feed                */
        ,   UNFINISHED_FIELD                            /*!< The last field 
 in the database file was not terminated by a record separator   */
        ,   UNFINISHED_RECORD                           /*!< The last 
 record in the database file was not terminated by a record separator  */
    }

    public char[] toString(ORJ_PARSE_ERROR f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
            ,   {   ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, "A 
 record separator was encountered during a content line tion"         }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last line in the 
 database was not terminated by a }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last field in 
 the database file was not terminated by a record separator"  }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last record in 
 the database file was not terminated by a record separator" }
        ];

        return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
    }


 

Mar 09 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
No worries

"Andrew Fedoniouk" <news terrainformatica.com> wrote in message 
news:d0ollq$17ud$1 digitaldaemon.com...
 Matthew, could you attach this as  d source file?
 Beg my pardon, but it is hardly readable.

 Thanks in advance,

 Andrew Fedoniouk.


 "Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
 news:d0oiuc$13r3$1 digitaldaemon.com...
 Just thought I'd share what I came up with for the enum => string 
 stuff,
 which is currently resident in std/openrj.d. If it receives a +ve 
 reaction
 we can move it into somewhere common, and use it for all enums. 
 (That's
 assuming, of course, we don't get something in the language to do it 
 for
 us.)

 Let me know what you think.

    private struct EnumString
    {
        int     value;
        char[]  str;
    };

    private template enum_to_string(T)
    {
        char[] enum_to_string(EnumString[] strings, T t)
        {
            // 'Optimised' search.
            //
            // Since many enums start at 0 and are contiguously 
 ordered,
 it's quite
            // likely that the value will equal the index. If it does, 
 we
 can just
            // return the string from that index.
            int index   =   cast(int)(t);

            if( index >= 0 &&
                index < strings.length &&
                strings[index].value == index)
            {
                return strings[index].str;
            }

            // Otherwise, just do a linear search
            foreach(EnumString s; strings)
            {
                if(cast(int)(t) == s.value)
                {
                    return s.str;
                }
            }

            return "<unknown>";
        }
    }

    /*
 /////////////////////////////////////////////////////////////////////////////
     * Enumerations
     */

    /** Flags that moderate the creation of Databases */
    public enum ORJ_FLAG
    {
            ORDER_FIELDS                    =   0x0001  /*!< Arranges 
 the
 fields in alphabetical order                  */
        ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes 
 blank
 records to be ignored                         */
    }

    public char[] toString(ORJ_FLAG f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the 
 fields
 in alphabetical order" }
            ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank 
 records
 to be ignored"        }
        ];

        return enum_to_string!(ORJ_FLAG)(strings, f);
    }

    /** General error codes */
    public enum ORJRC
    {
            SUCCESS                      =   0          /*!< Operation 
 was
 successful                                   */
        ,   CANNOT_OPEN_JAR_FILE                        /*!< The given 
 file
 does not exist, or cannot be accessed       */
        ,   NO_RECORDS                                  /*!< The 
 database
 file contained no records                     */
        ,   OUT_OF_MEMORY                               /*!< The API
 suffered memory exhaustion                         */
        ,   BAD_FILE_READ                               /*!< A read
 operation failed                                    */
        ,   PARSE_ERROR                                 /*!< Parsing 
 of the
 database file failed due to a syntax error  */
        ,   INVALID_INDEX                               /*!< An 
 invalid
 index was specified                             */
        ,   UNEXPECTED                                  /*!< An 
 unexpected
 condition was encountered                    */
        ,   INVALID_CONTENT                             /*!< The 
 database
 file contained invalid content                */
    }

    public char[] toString(ORJRC f)
    {
        const EnumString    strings[] =
        [
                {   ORJRC.SUCCESS,              "Operation was
             }
            ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file does 
 not
 exist, or cannot be accessed"          }
            ,   {   ORJRC.NO_RECORDS,           "The database file
 contained no records"                        }
            ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered 
 memory
 exhaustion"                            }
            ,   {   ORJRC.BAD_FILE_READ,        "A read operation
         }
            ,   {   ORJRC.PARSE_ERROR,          "Parsing of the 
 database
 file failed due to a syntax error"     }
            ,   {   ORJRC.INVALID_INDEX,        "An invalid index was
 specified"                                }
            ,   {   ORJRC.UNEXPECTED,           "An unexpected 
 condition
 was encountered"                       }
            ,   {   ORJRC.INVALID_CONTENT,      "The database file
 contained invalid content"                   }
        ];

        return enum_to_string!(ORJRC)(strings, f);
    }

    /** Parsing error codes */
    public enum ORJ_PARSE_ERROR
    {
            SUCCESS                         =   0       /*!< Parsing 
 was
 successful                                                         */
        ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A record
 separator was encountered during a content line continuation 
 */
        ,   UNFINISHED_LINE                             /*!< The last 
 line
 in the database was not terminated by a line-feed                */
        ,   UNFINISHED_FIELD                            /*!< The last 
 field
 in the database file was not terminated by a record separator   */
        ,   UNFINISHED_RECORD                           /*!< The last
 record in the database file was not terminated by a record separator 
 */
    }

    public char[] toString(ORJ_PARSE_ERROR f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
            ,   {   ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, 
 "A
 record separator was encountered during a content line 
       }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last line in 
 the
 database was not terminated by a }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last field 
 in
 the database file was not terminated by a record separator"  }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last 
 record in
 the database file was not terminated by a record separator" }
        ];

        return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
    }


Mar 09 2005
next sibling parent reply "Andrew Fedoniouk" <news terrainformatica.com> writes:
Thanks a lot,

What about this:

enum E {
  ZERO,
  ONE,
  TWO
}

char[] toString(E e)
{
  static char[][] map =
  [
    E.ZERO  :"primordial",
    E.ONE   :"first",
    E.TWO   :"second"
  ];
  return map[e];
}

for simple continuous enums?

Anyway enums which are sets of bits (0x01,0x02, 0x04...) in fact
need different toString implementation (string composition)

Andrew.




"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message 
news:d0omiq$19o7$1 digitaldaemon.com...
 No worries

 "Andrew Fedoniouk" <news terrainformatica.com> wrote in message 
 news:d0ollq$17ud$1 digitaldaemon.com...
 Matthew, could you attach this as  d source file?
 Beg my pardon, but it is hardly readable.

 Thanks in advance,

 Andrew Fedoniouk.


 "Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
 news:d0oiuc$13r3$1 digitaldaemon.com...
 Just thought I'd share what I came up with for the enum => string stuff,
 which is currently resident in std/openrj.d. If it receives a +ve 
 reaction
 we can move it into somewhere common, and use it for all enums. (That's
 assuming, of course, we don't get something in the language to do it for
 us.)

 Let me know what you think.

    private struct EnumString
    {
        int     value;
        char[]  str;
    };

    private template enum_to_string(T)
    {
        char[] enum_to_string(EnumString[] strings, T t)
        {
            // 'Optimised' search.
            //
            // Since many enums start at 0 and are contiguously ordered,
 it's quite
            // likely that the value will equal the index. If it does, we
 can just
            // return the string from that index.
            int index   =   cast(int)(t);

            if( index >= 0 &&
                index < strings.length &&
                strings[index].value == index)
            {
                return strings[index].str;
            }

            // Otherwise, just do a linear search
            foreach(EnumString s; strings)
            {
                if(cast(int)(t) == s.value)
                {
                    return s.str;
                }
            }

            return "<unknown>";
        }
    }

    /*
 /////////////////////////////////////////////////////////////////////////////
     * Enumerations
     */

    /** Flags that moderate the creation of Databases */
    public enum ORJ_FLAG
    {
            ORDER_FIELDS                    =   0x0001  /*!< Arranges the
 fields in alphabetical order                  */
        ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes blank
 records to be ignored                         */
    }

    public char[] toString(ORJ_FLAG f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the fields
 in alphabetical order" }
            ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank 
 records
 to be ignored"        }
        ];

        return enum_to_string!(ORJ_FLAG)(strings, f);
    }

    /** General error codes */
    public enum ORJRC
    {
            SUCCESS                      =   0          /*!< Operation 
 was
 successful                                   */
        ,   CANNOT_OPEN_JAR_FILE                        /*!< The given 
 file
 does not exist, or cannot be accessed       */
        ,   NO_RECORDS                                  /*!< The database
 file contained no records                     */
        ,   OUT_OF_MEMORY                               /*!< The API
 suffered memory exhaustion                         */
        ,   BAD_FILE_READ                               /*!< A read
 operation failed                                    */
        ,   PARSE_ERROR                                 /*!< Parsing of 
 the
 database file failed due to a syntax error  */
        ,   INVALID_INDEX                               /*!< An invalid
 index was specified                             */
        ,   UNEXPECTED                                  /*!< An 
 unexpected
 condition was encountered                    */
        ,   INVALID_CONTENT                             /*!< The database
 file contained invalid content                */
    }

    public char[] toString(ORJRC f)
    {
        const EnumString    strings[] =
        [
                {   ORJRC.SUCCESS,              "Operation was
             }
            ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file does not
 exist, or cannot be accessed"          }
            ,   {   ORJRC.NO_RECORDS,           "The database file
 contained no records"                        }
            ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered memory
 exhaustion"                            }
            ,   {   ORJRC.BAD_FILE_READ,        "A read operation
         }
            ,   {   ORJRC.PARSE_ERROR,          "Parsing of the database
 file failed due to a syntax error"     }
            ,   {   ORJRC.INVALID_INDEX,        "An invalid index was
 specified"                                }
            ,   {   ORJRC.UNEXPECTED,           "An unexpected condition
 was encountered"                       }
            ,   {   ORJRC.INVALID_CONTENT,      "The database file
 contained invalid content"                   }
        ];

        return enum_to_string!(ORJRC)(strings, f);
    }

    /** Parsing error codes */
    public enum ORJ_PARSE_ERROR
    {
            SUCCESS                         =   0       /*!< Parsing was
 successful                                                         */
        ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A record
 separator was encountered during a content line continuation */
        ,   UNFINISHED_LINE                             /*!< The last 
 line
 in the database was not terminated by a line-feed                */
        ,   UNFINISHED_FIELD                            /*!< The last 
 field
 in the database file was not terminated by a record separator   */
        ,   UNFINISHED_RECORD                           /*!< The last
 record in the database file was not terminated by a record separator */
    }

    public char[] toString(ORJ_PARSE_ERROR f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
            ,   {   ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, "A
 record separator was encountered during a content line }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last line in 
 the
 database was not terminated by a }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last field in
 the database file was not terminated by a record separator"  }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last record 
 in
 the database file was not terminated by a record separator" }
        ];

        return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
    }



Mar 09 2005
parent reply Kris <Kris_member pathlink.com> writes:
Why not push to get the enum-names exposed via reflection instead? I wouldn't
wish to have to re-type them all over again, in a different manner. Doesn't make
sense.

- Kris



In article <d0onfb$1afp$1 digitaldaemon.com>, Andrew Fedoniouk says...
Thanks a lot,

What about this:

enum E {
  ZERO,
  ONE,
  TWO
}

char[] toString(E e)
{
  static char[][] map =
  [
    E.ZERO  :"primordial",
    E.ONE   :"first",
    E.TWO   :"second"
  ];
  return map[e];
}

for simple continuous enums?

Anyway enums which are sets of bits (0x01,0x02, 0x04...) in fact
need different toString implementation (string composition)

Andrew.




"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message 
news:d0omiq$19o7$1 digitaldaemon.com...
 No worries

 "Andrew Fedoniouk" <news terrainformatica.com> wrote in message 
 news:d0ollq$17ud$1 digitaldaemon.com...
 Matthew, could you attach this as  d source file?
 Beg my pardon, but it is hardly readable.

 Thanks in advance,

 Andrew Fedoniouk.


 "Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
 news:d0oiuc$13r3$1 digitaldaemon.com...
 Just thought I'd share what I came up with for the enum => string stuff,
 which is currently resident in std/openrj.d. If it receives a +ve 
 reaction
 we can move it into somewhere common, and use it for all enums. (That's
 assuming, of course, we don't get something in the language to do it for
 us.)

 Let me know what you think.

    private struct EnumString
    {
        int     value;
        char[]  str;
    };

    private template enum_to_string(T)
    {
        char[] enum_to_string(EnumString[] strings, T t)
        {
            // 'Optimised' search.
            //
            // Since many enums start at 0 and are contiguously ordered,
 it's quite
            // likely that the value will equal the index. If it does, we
 can just
            // return the string from that index.
            int index   =   cast(int)(t);

            if( index >= 0 &&
                index < strings.length &&
                strings[index].value == index)
            {
                return strings[index].str;
            }

            // Otherwise, just do a linear search
            foreach(EnumString s; strings)
            {
                if(cast(int)(t) == s.value)
                {
                    return s.str;
                }
            }

            return "<unknown>";
        }
    }

    /*
 /////////////////////////////////////////////////////////////////////////////
     * Enumerations
     */

    /** Flags that moderate the creation of Databases */
    public enum ORJ_FLAG
    {
            ORDER_FIELDS                    =   0x0001  /*!< Arranges the
 fields in alphabetical order                  */
        ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes blank
 records to be ignored                         */
    }

    public char[] toString(ORJ_FLAG f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the fields
 in alphabetical order" }
            ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank 
 records
 to be ignored"        }
        ];

        return enum_to_string!(ORJ_FLAG)(strings, f);
    }

    /** General error codes */
    public enum ORJRC
    {
            SUCCESS                      =   0          /*!< Operation 
 was
 successful                                   */
        ,   CANNOT_OPEN_JAR_FILE                        /*!< The given 
 file
 does not exist, or cannot be accessed       */
        ,   NO_RECORDS                                  /*!< The database
 file contained no records                     */
        ,   OUT_OF_MEMORY                               /*!< The API
 suffered memory exhaustion                         */
        ,   BAD_FILE_READ                               /*!< A read
 operation failed                                    */
        ,   PARSE_ERROR                                 /*!< Parsing of 
 the
 database file failed due to a syntax error  */
        ,   INVALID_INDEX                               /*!< An invalid
 index was specified                             */
        ,   UNEXPECTED                                  /*!< An 
 unexpected
 condition was encountered                    */
        ,   INVALID_CONTENT                             /*!< The database
 file contained invalid content                */
    }

    public char[] toString(ORJRC f)
    {
        const EnumString    strings[] =
        [
                {   ORJRC.SUCCESS,              "Operation was
             }
            ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file does not
 exist, or cannot be accessed"          }
            ,   {   ORJRC.NO_RECORDS,           "The database file
 contained no records"                        }
            ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered memory
 exhaustion"                            }
            ,   {   ORJRC.BAD_FILE_READ,        "A read operation
         }
            ,   {   ORJRC.PARSE_ERROR,          "Parsing of the database
 file failed due to a syntax error"     }
            ,   {   ORJRC.INVALID_INDEX,        "An invalid index was
 specified"                                }
            ,   {   ORJRC.UNEXPECTED,           "An unexpected condition
 was encountered"                       }
            ,   {   ORJRC.INVALID_CONTENT,      "The database file
 contained invalid content"                   }
        ];

        return enum_to_string!(ORJRC)(strings, f);
    }

    /** Parsing error codes */
    public enum ORJ_PARSE_ERROR
    {
            SUCCESS                         =   0       /*!< Parsing was
 successful                                                         */
        ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A record
 separator was encountered during a content line continuation */
        ,   UNFINISHED_LINE                             /*!< The last 
 line
 in the database was not terminated by a line-feed                */
        ,   UNFINISHED_FIELD                            /*!< The last 
 field
 in the database file was not terminated by a record separator   */
        ,   UNFINISHED_RECORD                           /*!< The last
 record in the database file was not terminated by a record separator */
    }

    public char[] toString(ORJ_PARSE_ERROR f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
            ,   {   ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, "A
 record separator was encountered during a content line }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last line in 
 the
 database was not terminated by a }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last field in
 the database file was not terminated by a record separator"  }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last record 
 in
 the database file was not terminated by a record separator" }
        ];

        return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
    }




Mar 09 2005
next sibling parent reply "Andrew Fedoniouk" <news terrainformatica.com> writes:
Hi, Kris,

Ideally these Enum strings should come in different
languages. Right? So reflection will not help you here.

Reflection might help in other places but not too much.
I can see only couple areas where it may help:
persistent storages/OODB, and SOAP alike use cases.
Does anybody know other areas where reflection is desirable?

Andrew.



"Kris" <Kris_member pathlink.com> wrote in message 
news:d0op0e$1bnh$1 digitaldaemon.com...
 Why not push to get the enum-names exposed via reflection instead? I 
 wouldn't
 wish to have to re-type them all over again, in a different manner. 
 Doesn't make
 sense.

 - Kris



 In article <d0onfb$1afp$1 digitaldaemon.com>, Andrew Fedoniouk says...
Thanks a lot,

What about this:

enum E {
  ZERO,
  ONE,
  TWO
}

char[] toString(E e)
{
  static char[][] map =
  [
    E.ZERO  :"primordial",
    E.ONE   :"first",
    E.TWO   :"second"
  ];
  return map[e];
}

for simple continuous enums?

Anyway enums which are sets of bits (0x01,0x02, 0x04...) in fact
need different toString implementation (string composition)

Andrew.




"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
news:d0omiq$19o7$1 digitaldaemon.com...
 No worries

 "Andrew Fedoniouk" <news terrainformatica.com> wrote in message
 news:d0ollq$17ud$1 digitaldaemon.com...
 Matthew, could you attach this as  d source file?
 Beg my pardon, but it is hardly readable.

 Thanks in advance,

 Andrew Fedoniouk.


 "Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
 news:d0oiuc$13r3$1 digitaldaemon.com...
 Just thought I'd share what I came up with for the enum => string 
 stuff,
 which is currently resident in std/openrj.d. If it receives a +ve
 reaction
 we can move it into somewhere common, and use it for all enums. 
 (That's
 assuming, of course, we don't get something in the language to do it 
 for
 us.)

 Let me know what you think.

    private struct EnumString
    {
        int     value;
        char[]  str;
    };

    private template enum_to_string(T)
    {
        char[] enum_to_string(EnumString[] strings, T t)
        {
            // 'Optimised' search.
            //
            // Since many enums start at 0 and are contiguously 
 ordered,
 it's quite
            // likely that the value will equal the index. If it does, 
 we
 can just
            // return the string from that index.
            int index   =   cast(int)(t);

            if( index >= 0 &&
                index < strings.length &&
                strings[index].value == index)
            {
                return strings[index].str;
            }

            // Otherwise, just do a linear search
            foreach(EnumString s; strings)
            {
                if(cast(int)(t) == s.value)
                {
                    return s.str;
                }
            }

            return "<unknown>";
        }
    }

    /*
 /////////////////////////////////////////////////////////////////////////////
     * Enumerations
     */

    /** Flags that moderate the creation of Databases */
    public enum ORJ_FLAG
    {
            ORDER_FIELDS                    =   0x0001  /*!< Arranges 
 the
 fields in alphabetical order                  */
        ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes 
 blank
 records to be ignored                         */
    }

    public char[] toString(ORJ_FLAG f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the 
 fields
 in alphabetical order" }
            ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank
 records
 to be ignored"        }
        ];

        return enum_to_string!(ORJ_FLAG)(strings, f);
    }

    /** General error codes */
    public enum ORJRC
    {
            SUCCESS                      =   0          /*!< Operation
 was
 successful                                   */
        ,   CANNOT_OPEN_JAR_FILE                        /*!< The given
 file
 does not exist, or cannot be accessed       */
        ,   NO_RECORDS                                  /*!< The 
 database
 file contained no records                     */
        ,   OUT_OF_MEMORY                               /*!< The API
 suffered memory exhaustion                         */
        ,   BAD_FILE_READ                               /*!< A read
 operation failed                                    */
        ,   PARSE_ERROR                                 /*!< Parsing of
 the
 database file failed due to a syntax error  */
        ,   INVALID_INDEX                               /*!< An invalid
 index was specified                             */
        ,   UNEXPECTED                                  /*!< An
 unexpected
 condition was encountered                    */
        ,   INVALID_CONTENT                             /*!< The 
 database
 file contained invalid content                */
    }

    public char[] toString(ORJRC f)
    {
        const EnumString    strings[] =
        [
                {   ORJRC.SUCCESS,              "Operation was
             }
            ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file does 
 not
 exist, or cannot be accessed"          }
            ,   {   ORJRC.NO_RECORDS,           "The database file
 contained no records"                        }
            ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered 
 memory
 exhaustion"                            }
            ,   {   ORJRC.BAD_FILE_READ,        "A read operation
         }
            ,   {   ORJRC.PARSE_ERROR,          "Parsing of the 
 database
 file failed due to a syntax error"     }
            ,   {   ORJRC.INVALID_INDEX,        "An invalid index was
 specified"                                }
            ,   {   ORJRC.UNEXPECTED,           "An unexpected 
 condition
 was encountered"                       }
            ,   {   ORJRC.INVALID_CONTENT,      "The database file
 contained invalid content"                   }
        ];

        return enum_to_string!(ORJRC)(strings, f);
    }

    /** Parsing error codes */
    public enum ORJ_PARSE_ERROR
    {
            SUCCESS                         =   0       /*!< Parsing 
 was
 successful                                                         */
        ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A record
 separator was encountered during a content line continuation */
        ,   UNFINISHED_LINE                             /*!< The last
 line
 in the database was not terminated by a line-feed                */
        ,   UNFINISHED_FIELD                            /*!< The last
 field
 in the database file was not terminated by a record separator   */
        ,   UNFINISHED_RECORD                           /*!< The last
 record in the database file was not terminated by a record separator 
 */
    }

    public char[] toString(ORJ_PARSE_ERROR f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
            ,   {   ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, 
 "A
 record separator was encountered during a content line }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last line in
 the
 database was not terminated by a }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last field 
 in
 the database file was not terminated by a record separator"  }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last record
 in
 the database file was not terminated by a record separator" }
        ];

        return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
    }





Mar 09 2005
next sibling parent reply Paul Bonser <misterpib gmail.com> writes:
 Does anybody know other areas where reflection is desirable?

Embedded Scripting, I'd imagine. I'm working on a game engine (in D, of course) and I'm going to want to embed a scripting language of some sort into it (haven't decided what to use yet, but I really want something that is bytecode-compiled...but that's another topic). It would be really handy to be able to call any function (and access any variable) I wanted from a script, without having to manually add a hook for each function I wanted to call or variable I wanted to access. Just add a couple of functions that look up the name you gave, call it if it's there, give an error if it isn't. It would make the scripting language better integrated into the program, without all the extra coding of doing it manually. Also, I'd like to be able to pop up a scripting console in-game (for when I'm developing it, at least..) and instantiate objects of various types and call functions wilily-nilly, as well as modifying objects and such that already exist. (again, without having to manually tell the scripting language about each and every data type that's out there.) Oh it would make me so happy to be able to do that. I believe it is also good for debugging and adding class-browsers and did I mention scripting? :P So I guess until reflection is made part of the language (or something) I'll have to just do a "sorta" reflection by making every class a subclass of a Reflection class and have to keep an associative array of all the function names and variable names with delegates and pointers and...blah, that's what I want to not have to do :( -- -PIB -- "C++ also supports the notion of *friends*: cooperative classes that are permitted to see each other's private parts." - Grady Booch
Mar 10 2005
next sibling parent Paul Bonser <misterpib gmail.com> writes:
Paul Bonser wrote:
 
 Does anybody know other areas where reflection is desirable?

Embedded Scripting, I'd imagine. I'm working on a game engine (in D, of course) and I'm going to want to embed a scripting language of some sort into it (haven't decided what to use yet, but I really want something that is bytecode-compiled...but that's another topic). It would be really handy to be able to call any function (and access any variable) I wanted from a script, without having to manually add a hook for each function I wanted to call or variable I wanted to access. Just add a couple of functions that look up the name you gave, call it if it's there, give an error if it isn't. It would make the scripting language better integrated into the program, without all the extra coding of doing it manually. Also, I'd like to be able to pop up a scripting console in-game (for when I'm developing it, at least..) and instantiate objects of various types and call functions wilily-nilly, as well as modifying objects and such that already exist. (again, without having to manually tell the scripting language about each and every data type that's out there.) Oh it would make me so happy to be able to do that. I believe it is also good for debugging and adding class-browsers and did I mention scripting? :P So I guess until reflection is made part of the language (or something) I'll have to just do a "sorta" reflection by making every class a subclass of a Reflection class and have to keep an associative array of all the function names and variable names with delegates and pointers and...blah, that's what I want to not have to do :(

Well, I should say that I would probably write a script or program or whatnot to filter my files and add all this "artificial reflection" in for me. But again, I'd much rather not have to do this... -- -PIB -- "C++ also supports the notion of *friends*: cooperative classes that are permitted to see each other's private parts." - Grady Booch
Mar 10 2005
prev sibling parent "Andrew Fedoniouk" <news terrainformatica.com> writes:
 Embedded Scripting, I'd imagine.

I would agree if your Script will share same basic constructions with D: types, classes, arrays, etc. Anyway it is extremely bad design to allow to script "to see private parts" of host implementation. So you will create an isolation layer. Which will be anyway sort of IDispatch with VARIANT or the like with function table like: delegate value (uint argn, value[] argv) functbl[symbol_t]; Andrew Fedoniouk. http://terrainformatica.com "Paul Bonser" <misterpib gmail.com> wrote in message news:d0p15l$1l13$1 digitaldaemon.com...
 Does anybody know other areas where reflection is desirable?

Embedded Scripting, I'd imagine. I'm working on a game engine (in D, of course) and I'm going to want to embed a scripting language of some sort into it (haven't decided what to use yet, but I really want something that is bytecode-compiled...but that's another topic). It would be really handy to be able to call any function (and access any variable) I wanted from a script, without having to manually add a hook for each function I wanted to call or variable I wanted to access. Just add a couple of functions that look up the name you gave, call it if it's there, give an error if it isn't. It would make the scripting language better integrated into the program, without all the extra coding of doing it manually. Also, I'd like to be able to pop up a scripting console in-game (for when I'm developing it, at least..) and instantiate objects of various types and call functions wilily-nilly, as well as modifying objects and such that already exist. (again, without having to manually tell the scripting language about each and every data type that's out there.) Oh it would make me so happy to be able to do that. I believe it is also good for debugging and adding class-browsers and did I mention scripting? :P So I guess until reflection is made part of the language (or something) I'll have to just do a "sorta" reflection by making every class a subclass of a Reflection class and have to keep an associative array of all the function names and variable names with delegates and pointers and...blah, that's what I want to not have to do :( -- -PIB -- "C++ also supports the notion of *friends*: cooperative classes that are permitted to see each other's private parts." - Grady Booch

Mar 10 2005
prev sibling next sibling parent pragma <pragma_member pathlink.com> writes:
In article <d0ossh$1f4t$1 digitaldaemon.com>, Andrew Fedoniouk says...
Ideally these Enum strings should come in different
languages. Right? So reflection will not help you here.

Reflection might help in other places but not too much.
I can see only couple areas where it may help:
persistent storages/OODB, and SOAP alike use cases.
Does anybody know other areas where reflection is desirable?

AFAIK: the goal of getting an enum's name is really just a form of a "lexical cast"; something that isn't typically more than just raw reflection. I think the notion here is "locale be damned" and just give up the name of the constant used in the source. As you mentioned, generic persistence via reflection would be a welcome addition. SOAP, RPC, CORBA (et al.) and DLL interop can all benefit hugely from reflection, and is by no means a fringe use of the technology. D could easily be a business language of choice if you had runtime-generated transparent proxies like .NET. As for other areas? A (future) D-specific debugger could make very good use of deeper reflection information. Also, generic programming could benefit greatly from richer runtime (and compile time!) type information. Outside that, it really just lends to the language's flexibility overall which can only help its adoption rate. We really don't want "D.Boost" when we can have all of its capability built-into the D/phobos itself. - EricAnderton at yahoo
Mar 10 2005
prev sibling parent reply kris <fu bar.org> writes:
Hey Andrew;

I figured Matthew was using these enum-names for a non-i18n application 
only ~ once you start getting into locale-specifics, there's a whole lot 
more to consider (as I'm sure you know) and the strings themselves would 
very likely be externalized in one manner or another: making this topic 
somewhat moot?

Of course, this is probably now way-off topic; so I'll mention the ICU 
tools/APIs once again (WRT this domain) and then shuttup ...

- Kris


Andrew Fedoniouk wrote:
 Hi, Kris,
 
 Ideally these Enum strings should come in different
 languages. Right? So reflection will not help you here.
 
 Reflection might help in other places but not too much.
 I can see only couple areas where it may help:
 persistent storages/OODB, and SOAP alike use cases.
 Does anybody know other areas where reflection is desirable?
 
 Andrew.
 
 
 
 "Kris" <Kris_member pathlink.com> wrote in message 
 news:d0op0e$1bnh$1 digitaldaemon.com...
 
Why not push to get the enum-names exposed via reflection instead? I 
wouldn't
wish to have to re-type them all over again, in a different manner. 
Doesn't make
sense.

- Kris



In article <d0onfb$1afp$1 digitaldaemon.com>, Andrew Fedoniouk says...

Thanks a lot,

What about this:

enum E {
 ZERO,
 ONE,
 TWO
}

char[] toString(E e)
{
 static char[][] map =
 [
   E.ZERO  :"primordial",
   E.ONE   :"first",
   E.TWO   :"second"
 ];
 return map[e];
}

for simple continuous enums?

Anyway enums which are sets of bits (0x01,0x02, 0x04...) in fact
need different toString implementation (string composition)

Andrew.




"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
news:d0omiq$19o7$1 digitaldaemon.com...

No worries

"Andrew Fedoniouk" <news terrainformatica.com> wrote in message
news:d0ollq$17ud$1 digitaldaemon.com...

Matthew, could you attach this as  d source file?
Beg my pardon, but it is hardly readable.

Thanks in advance,

Andrew Fedoniouk.


"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
news:d0oiuc$13r3$1 digitaldaemon.com...

Just thought I'd share what I came up with for the enum => string 
stuff,
which is currently resident in std/openrj.d. If it receives a +ve
reaction
we can move it into somewhere common, and use it for all enums. 
(That's
assuming, of course, we don't get something in the language to do it 
for
us.)

Let me know what you think.

   private struct EnumString
   {
       int     value;
       char[]  str;
   };

   private template enum_to_string(T)
   {
       char[] enum_to_string(EnumString[] strings, T t)
       {
           // 'Optimised' search.
           //
           // Since many enums start at 0 and are contiguously 
ordered,
it's quite
           // likely that the value will equal the index. If it does, 
we
can just
           // return the string from that index.
           int index   =   cast(int)(t);

           if( index >= 0 &&
               index < strings.length &&
               strings[index].value == index)
           {
               return strings[index].str;
           }

           // Otherwise, just do a linear search
           foreach(EnumString s; strings)
           {
               if(cast(int)(t) == s.value)
               {
                   return s.str;
               }
           }

           return "<unknown>";
       }
   }

   /*
/////////////////////////////////////////////////////////////////////////////
    * Enumerations
    */

   /** Flags that moderate the creation of Databases */
   public enum ORJ_FLAG
   {
           ORDER_FIELDS                    =   0x0001  /*!< Arranges 
the
fields in alphabetical order                  */
       ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes 
blank
records to be ignored                         */
   }

   public char[] toString(ORJ_FLAG f)
   {
       const EnumString    strings[] =
       [
               {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the 
fields
in alphabetical order" }
           ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank
records
to be ignored"        }
       ];

       return enum_to_string!(ORJ_FLAG)(strings, f);
   }

   /** General error codes */
   public enum ORJRC
   {
           SUCCESS                      =   0          /*!< Operation
was
successful                                   */
       ,   CANNOT_OPEN_JAR_FILE                        /*!< The given
file
does not exist, or cannot be accessed       */
       ,   NO_RECORDS                                  /*!< The 
database
file contained no records                     */
       ,   OUT_OF_MEMORY                               /*!< The API
suffered memory exhaustion                         */
       ,   BAD_FILE_READ                               /*!< A read
operation failed                                    */
       ,   PARSE_ERROR                                 /*!< Parsing of
the
database file failed due to a syntax error  */
       ,   INVALID_INDEX                               /*!< An invalid
index was specified                             */
       ,   UNEXPECTED                                  /*!< An
unexpected
condition was encountered                    */
       ,   INVALID_CONTENT                             /*!< The 
database
file contained invalid content                */
   }

   public char[] toString(ORJRC f)
   {
       const EnumString    strings[] =
       [
               {   ORJRC.SUCCESS,              "Operation was
            }
           ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file does 
not
exist, or cannot be accessed"          }
           ,   {   ORJRC.NO_RECORDS,           "The database file
contained no records"                        }
           ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered 
memory
exhaustion"                            }
           ,   {   ORJRC.BAD_FILE_READ,        "A read operation
        }
           ,   {   ORJRC.PARSE_ERROR,          "Parsing of the 
database
file failed due to a syntax error"     }
           ,   {   ORJRC.INVALID_INDEX,        "An invalid index was
specified"                                }
           ,   {   ORJRC.UNEXPECTED,           "An unexpected 
condition
was encountered"                       }
           ,   {   ORJRC.INVALID_CONTENT,      "The database file
contained invalid content"                   }
       ];

       return enum_to_string!(ORJRC)(strings, f);
   }

   /** Parsing error codes */
   public enum ORJ_PARSE_ERROR
   {
           SUCCESS                         =   0       /*!< Parsing 
was
successful                                                         */
       ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A record
separator was encountered during a content line continuation */
       ,   UNFINISHED_LINE                             /*!< The last
line
in the database was not terminated by a line-feed                */
       ,   UNFINISHED_FIELD                            /*!< The last
field
in the database file was not terminated by a record separator   */
       ,   UNFINISHED_RECORD                           /*!< The last
record in the database file was not terminated by a record separator 
*/
   }

   public char[] toString(ORJ_PARSE_ERROR f)
   {
       const EnumString    strings[] =
       [
               {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
           ,   {   ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, 
"A
record separator was encountered during a content line }
           ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last line in
the
database was not terminated by a }
           ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last field 
in
the database file was not terminated by a record separator"  }
           ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last record
in
the database file was not terminated by a record separator" }
       ];

       return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
   }






Mar 10 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
It's that, in Open-RJ, two of the three enums are error codes. In the C 
library there's a static array of structs mapping the value to a string.

This is a really common idiom, but painfully verbose and also very 
fragile - it's all too easy to get the Doxygen doc strings out of step 
with the string literals used in the translation - so I figured that D 
might address this. I still feel that that's worthwhile. (Note: in C, 
one can keep it all in the DRY SPOT by using macros, which we, er, 
cannot do in D. <g>)

Of course, this does not address localisation, and I don't suggest it 
does. It's just a safer shortcut for what we do now anyway.

I've been thinking that rather than strings we might also associate 
string identifiers, which would be hooked into the i18n framework that, 
as yet, does not exist. ;)


"kris" <fu bar.org> wrote in message 
news:d0ps0h$2fbt$1 digitaldaemon.com...
 Hey Andrew;

 I figured Matthew was using these enum-names for a non-i18n 
 application only ~ once you start getting into locale-specifics, 
 there's a whole lot more to consider (as I'm sure you know) and the 
 strings themselves would very likely be externalized in one manner or 
 another: making this topic somewhat moot?

 Of course, this is probably now way-off topic; so I'll mention the ICU 
 tools/APIs once again (WRT this domain) and then shuttup ...

 - Kris


 Andrew Fedoniouk wrote:
 Hi, Kris,

 Ideally these Enum strings should come in different
 languages. Right? So reflection will not help you here.

 Reflection might help in other places but not too much.
 I can see only couple areas where it may help:
 persistent storages/OODB, and SOAP alike use cases.
 Does anybody know other areas where reflection is desirable?

 Andrew.



 "Kris" <Kris_member pathlink.com> wrote in message 
 news:d0op0e$1bnh$1 digitaldaemon.com...

Why not push to get the enum-names exposed via reflection instead? I 
wouldn't
wish to have to re-type them all over again, in a different manner. 
Doesn't make
sense.

- Kris



In article <d0onfb$1afp$1 digitaldaemon.com>, Andrew Fedoniouk 
says...

Thanks a lot,

What about this:

enum E {
 ZERO,
 ONE,
 TWO
}

char[] toString(E e)
{
 static char[][] map =
 [
   E.ZERO  :"primordial",
   E.ONE   :"first",
   E.TWO   :"second"
 ];
 return map[e];
}

for simple continuous enums?

Anyway enums which are sets of bits (0x01,0x02, 0x04...) in fact
need different toString implementation (string composition)

Andrew.




"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
news:d0omiq$19o7$1 digitaldaemon.com...

No worries

"Andrew Fedoniouk" <news terrainformatica.com> wrote in message
news:d0ollq$17ud$1 digitaldaemon.com...

Matthew, could you attach this as  d source file?
Beg my pardon, but it is hardly readable.

Thanks in advance,

Andrew Fedoniouk.


"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
news:d0oiuc$13r3$1 digitaldaemon.com...

Just thought I'd share what I came up with for the enum => string 
stuff,
which is currently resident in std/openrj.d. If it receives a +ve
reaction
we can move it into somewhere common, and use it for all enums. 
(That's
assuming, of course, we don't get something in the language to do 
it for
us.)

Let me know what you think.

   private struct EnumString
   {
       int     value;
       char[]  str;
   };

   private template enum_to_string(T)
   {
       char[] enum_to_string(EnumString[] strings, T t)
       {
           // 'Optimised' search.
           //
           // Since many enums start at 0 and are contiguously 
 ordered,
it's quite
           // likely that the value will equal the index. If it 
 does, we
can just
           // return the string from that index.
           int index   =   cast(int)(t);

           if( index >= 0 &&
               index < strings.length &&
               strings[index].value == index)
           {
               return strings[index].str;
           }

           // Otherwise, just do a linear search
           foreach(EnumString s; strings)
           {
               if(cast(int)(t) == s.value)
               {
                   return s.str;
               }
           }

           return "<unknown>";
       }
   }

   /*
/////////////////////////////////////////////////////////////////////////////
    * Enumerations
    */

   /** Flags that moderate the creation of Databases */
   public enum ORJ_FLAG
   {
           ORDER_FIELDS                    =   0x0001  /*!< 
 Arranges the
fields in alphabetical order                  */
       ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< 
 Causes blank
records to be ignored                         */
   }

   public char[] toString(ORJ_FLAG f)
   {
       const EnumString    strings[] =
       [
               {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the 
 fields
in alphabetical order" }
           ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank
records
to be ignored"        }
       ];

       return enum_to_string!(ORJ_FLAG)(strings, f);
   }

   /** General error codes */
   public enum ORJRC
   {
           SUCCESS                      =   0          /*!< 
 Operation
was
successful                                   */
       ,   CANNOT_OPEN_JAR_FILE                        /*!< The 
 given
file
does not exist, or cannot be accessed       */
       ,   NO_RECORDS                                  /*!< The 
 database
file contained no records                     */
       ,   OUT_OF_MEMORY                               /*!< The 
 API
suffered memory exhaustion                         */
       ,   BAD_FILE_READ                               /*!< A 
 read
operation failed                                    */
       ,   PARSE_ERROR                                 /*!< 
 Parsing of
the
database file failed due to a syntax error  */
       ,   INVALID_INDEX                               /*!< An 
 invalid
index was specified                             */
       ,   UNEXPECTED                                  /*!< An
unexpected
condition was encountered                    */
       ,   INVALID_CONTENT                             /*!< The 
 database
file contained invalid content                */
   }

   public char[] toString(ORJRC f)
   {
       const EnumString    strings[] =
       [
               {   ORJRC.SUCCESS,              "Operation was
            }
           ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file 
 does not
exist, or cannot be accessed"          }
           ,   {   ORJRC.NO_RECORDS,           "The database file
contained no records"                        }
           ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered 
 memory
exhaustion"                            }
           ,   {   ORJRC.BAD_FILE_READ,        "A read operation
        }
           ,   {   ORJRC.PARSE_ERROR,          "Parsing of the 
 database
file failed due to a syntax error"     }
           ,   {   ORJRC.INVALID_INDEX,        "An invalid index 
 was
specified"                                }
           ,   {   ORJRC.UNEXPECTED,           "An unexpected 
 condition
was encountered"                       }
           ,   {   ORJRC.INVALID_CONTENT,      "The database file
contained invalid content"                   }
       ];

       return enum_to_string!(ORJRC)(strings, f);
   }

   /** Parsing error codes */
   public enum ORJ_PARSE_ERROR
   {
           SUCCESS                         =   0       /*!< 
 Parsing was
successful 
*/
       ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A 
 record
separator was encountered during a content line continuation */
       ,   UNFINISHED_LINE                             /*!< The 
 last
line
in the database was not terminated by a line-feed 
*/
       ,   UNFINISHED_FIELD                            /*!< The 
 last
field
in the database file was not terminated by a record separator 
*/
       ,   UNFINISHED_RECORD                           /*!< The 
 last
record in the database file was not terminated by a record 
separator */
   }

   public char[] toString(ORJ_PARSE_ERROR f)
   {
       const EnumString    strings[] =
       [
               {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
           ,   { 
 ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, "A
record separator was encountered during a content line }
           ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last 
 line in
the
database was not terminated by a }
           ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last 
 field in
the database file was not terminated by a record separator"  }
           ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last 
 record
in
the database file was not terminated by a record separator" }
       ];

       return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
   }







Mar 10 2005
parent reply Kris <Kris_member pathlink.com> writes:
In article <d0qish$7hl$1 digitaldaemon.com>, Matthew says...
It's that, in Open-RJ, two of the three enums are error codes. In the C 
library there's a static array of structs mapping the value to a string.

This is a really common idiom, but painfully verbose and also very 
fragile - it's all too easy to get the Doxygen doc strings out of step 
with the string literals used in the translation - so I figured that D 
might address this. I still feel that that's worthwhile. (Note: in C, 
one can keep it all in the DRY SPOT by using macros, which we, er, 
cannot do in D. <g>)

If it is so common, then it should be exposed by the compiler via reflection. That way it would not be fragile, and would stay in that DRY SPOT.
Of course, this does not address localisation, and I don't suggest it 
does. It's just a safer shortcut for what we do now anyway.

I've been thinking that rather than strings we might also associate 
string identifiers, which would be hooked into the i18n framework that, 
as yet, does not exist. ;)

That i18n framework *does* exist. It's called ICU, and it has a slew of tools for producing, configuring, editing, and managing such resources. The best part about ICU is the level of maturity, and the vast sums of money poured into it by IBM et. al. It may not be ideal, but it's a long way down a reasonable path.
"kris" <fu bar.org> wrote in message 
news:d0ps0h$2fbt$1 digitaldaemon.com...
 Hey Andrew;

 I figured Matthew was using these enum-names for a non-i18n 
 application only ~ once you start getting into locale-specifics, 
 there's a whole lot more to consider (as I'm sure you know) and the 
 strings themselves would very likely be externalized in one manner or 
 another: making this topic somewhat moot?

 Of course, this is probably now way-off topic; so I'll mention the ICU 
 tools/APIs once again (WRT this domain) and then shuttup ...

 - Kris


Mar 10 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
It's that, in Open-RJ, two of the three enums are error codes. In the 
C
library there's a static array of structs mapping the value to a 
string.

This is a really common idiom, but painfully verbose and also very
fragile - it's all too easy to get the Doxygen doc strings out of step
with the string literals used in the translation - so I figured that D
might address this. I still feel that that's worthwhile. (Note: in C,
one can keep it all in the DRY SPOT by using macros, which we, er,
cannot do in D. <g>)

If it is so common, then it should be exposed by the compiler via reflection. That way it would not be fragile, and would stay in that DRY SPOT.

Cool.
Of course, this does not address localisation, and I don't suggest it
does. It's just a safer shortcut for what we do now anyway.

I've been thinking that rather than strings we might also associate
string identifiers, which would be hooked into the i18n framework 
that,
as yet, does not exist. ;)

That i18n framework *does* exist. It's called ICU, and it has a slew of tools for producing, configuring, editing, and managing such resources. The best part about ICU is the level of maturity, and the vast sums of money poured into it by IBM et. al. It may not be ideal, but it's a long way down a reasonable path.

Sorry. I meant like not something in D yet.
"kris" <fu bar.org> wrote in message
news:d0ps0h$2fbt$1 digitaldaemon.com...
 Hey Andrew;

 I figured Matthew was using these enum-names for a non-i18n
 application only ~ once you start getting into locale-specifics,
 there's a whole lot more to consider (as I'm sure you know) and the
 strings themselves would very likely be externalized in one manner 
 or
 another: making this topic somewhat moot?

 Of course, this is probably now way-off topic; so I'll mention the 
 ICU
 tools/APIs once again (WRT this domain) and then shuttup ...

 - Kris



Mar 10 2005
parent reply Kris <Kris_member pathlink.com> writes:
In article <d0qrj5$g81$1 digitaldaemon.com>, Matthew says...
 If it is so common, then it should be exposed by the compiler via 
 reflection.
 That way it would not be fragile, and would stay in that DRY SPOT.

Cool.

So how about it? What do folks think about a compiler-option to retain & expose reflection material such as enum-names? It would presumeably be a step along the path of reflection, and probably won't even be seriously considered until after 1.0 ... ? That would appear to be a neat way of providing tags for externalized content, including i18n considerations.
 That i18n framework *does* exist. It's called ICU, and it has a slew 
 of tools
 for producing, configuring, editing, and managing such resources. The 
 best part
 about ICU is the level of maturity, and the vast sums of money poured 
 into it by
 IBM et. al.

 It may not be ideal, but it's a long way down a reasonable path.

Sorry. I meant like not something in D yet.

Not to be argumentative, but it kinda' is available in D; we've got wrappers for almost all of the ICU APIs :-) Perhaps that's not what you meant ...
Mar 10 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
"Kris" <Kris_member pathlink.com> wrote in message 
news:d0qvv9$k3q$1 digitaldaemon.com...
 In article <d0qrj5$g81$1 digitaldaemon.com>, Matthew says...
 If it is so common, then it should be exposed by the compiler via
 reflection.
 That way it would not be fragile, and would stay in that DRY SPOT.

Cool.

So how about it? What do folks think about a compiler-option to retain & expose reflection material such as enum-names? It would presumeably be a step along the path of reflection, and probably won't even be seriously considered until after 1.0 ... ? That would appear to be a neat way of providing tags for externalized content, including i18n considerations.

I'm certainly keen to here: - from the group whether this is desirable - from the group whether there might be slight differences from the way I've expressed it that would be preferable - from Walter as to whether this is something that can be readily incorporated into the language.
 That i18n framework *does* exist. It's called ICU, and it has a slew
 of tools
 for producing, configuring, editing, and managing such resources. 
 The
 best part
 about ICU is the level of maturity, and the vast sums of money 
 poured
 into it by
 IBM et. al.

 It may not be ideal, but it's a long way down a reasonable path.

Sorry. I meant like not something in D yet.

Not to be argumentative, but it kinda' is available in D; we've got wrappers for almost all of the ICU APIs :-) Perhaps that's not what you meant ...

Kris, I'm largely ignorant of the subject, and, apparently, was purely pontifulating. :-)
Mar 10 2005
next sibling parent pragma <pragma_member pathlink.com> writes:
In article <d0r2a1$me8$1 digitaldaemon.com>, Matthew says...
"Kris" <Kris_member pathlink.com> wrote in message 
 So how about it? What do folks think about a compiler-option to retain 
 & expose
 reflection material such as enum-names? It would presumeably be a step 
 along the
 path of reflection, and probably won't even be seriously considered 
 until after
 1.0 ... ?

 That would appear to be a neat way of providing tags for externalized 
 content,
 including i18n considerations.

I'm certainly keen to here: - from the group whether this is desirable - from the group whether there might be slight differences from the way I've expressed it that would be preferable

I'll bite. :) I think that a full-on reflection system is desireable, but realizing that goal should probably be done as a wholesale design, rather than as a piecemeal set of improvements. I'd like to see us back something really close to the right design the first time round, rather than have to refactor needlessly as we go. As for enums, something transparent like
 enum Test{
    FOO,BAR,GORF
 };
 
 Test t = FOO;
 char[] name = typeid(Test).getValueName(t);
 char[] name2 = t.typeinfo.getValueName(t); // equivalent

I would like to void *against* any idea for the following c++ boost-ism:
 char[] name = lexical_cast!(char[])(t);

.. we can do better than that. As for a compiler option, I think that's a moot point. If someone is going to write code that's "lean and mean", why wouldn't they just write procedural code and leave it at that? After all, if you don't use any user-defined types, then the only typeinfo instances added to the app are for your scalar and array types. Classes already present overhead in the form of type information and v-tables already, so the needed metadata to fully support a complete reflection system probably won't bloat things too much. - EricAnderton at yahoo
Mar 10 2005
prev sibling parent Sean Kelly <sean f4.ca> writes:
In article <d0r2a1$me8$1 digitaldaemon.com>, Matthew says...
"Kris" <Kris_member pathlink.com> wrote in message 
news:d0qvv9$k3q$1 digitaldaemon.com...
 So how about it? What do folks think about a compiler-option to retain 
 & expose
 reflection material such as enum-names? It would presumeably be a step 
 along the
 path of reflection, and probably won't even be seriously considered 
 until after
 1.0 ... ?

 That would appear to be a neat way of providing tags for externalized 
 content,
 including i18n considerations.

I'm certainly keen to here: - from the group whether this is desirable - from the group whether there might be slight differences from the way I've expressed it that would be preferable - from Walter as to whether this is something that can be readily incorporated into the language.

Some reflection is better than no reflection IMO. And were I to use such a feature, it would have to be built into the compiler or at least supplied with a standard compiler package.
 Not to be argumentative, but it kinda' is available in D; we've got 
 wrappers for almost all of the ICU APIs :-)

 Perhaps that's not what you meant ...

Kris, I'm largely ignorant of the subject, and, apparently, was purely pontifulating. :-)

Kris picked up the ball when Jill disappeared and did much of the work himself. It's over at dsource :) Sean
Mar 11 2005
prev sibling parent "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
That's what I wanted, and proposed some days ago. The code I've manually 
provided is what I hope would be built in to the compiler. It's 
efficient - I bet more efficient than any based on AAs, esp. given the 
value==index optimisation - and does not do any runtime allocation. If 
the compiler simply did that for us - with expanded syntax for the 
strings (or string ids!!) - I think it'd be great.

"Kris" <Kris_member pathlink.com> wrote in message 
news:d0op0e$1bnh$1 digitaldaemon.com...
 Why not push to get the enum-names exposed via reflection instead? I 
 wouldn't
 wish to have to re-type them all over again, in a different manner. 
 Doesn't make
 sense.

 - Kris



 In article <d0onfb$1afp$1 digitaldaemon.com>, Andrew Fedoniouk says...
Thanks a lot,

What about this:

enum E {
  ZERO,
  ONE,
  TWO
}

char[] toString(E e)
{
  static char[][] map =
  [
    E.ZERO  :"primordial",
    E.ONE   :"first",
    E.TWO   :"second"
  ];
  return map[e];
}

for simple continuous enums?

Anyway enums which are sets of bits (0x01,0x02, 0x04...) in fact
need different toString implementation (string composition)

Andrew.




"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
news:d0omiq$19o7$1 digitaldaemon.com...
 No worries

 "Andrew Fedoniouk" <news terrainformatica.com> wrote in message
 news:d0ollq$17ud$1 digitaldaemon.com...
 Matthew, could you attach this as  d source file?
 Beg my pardon, but it is hardly readable.

 Thanks in advance,

 Andrew Fedoniouk.


 "Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
 news:d0oiuc$13r3$1 digitaldaemon.com...
 Just thought I'd share what I came up with for the enum => string 
 stuff,
 which is currently resident in std/openrj.d. If it receives a +ve
 reaction
 we can move it into somewhere common, and use it for all enums. 
 (That's
 assuming, of course, we don't get something in the language to do 
 it for
 us.)

 Let me know what you think.

    private struct EnumString
    {
        int     value;
        char[]  str;
    };

    private template enum_to_string(T)
    {
        char[] enum_to_string(EnumString[] strings, T t)
        {
            // 'Optimised' search.
            //
            // Since many enums start at 0 and are contiguously 
 ordered,
 it's quite
            // likely that the value will equal the index. If it 
 does, we
 can just
            // return the string from that index.
            int index   =   cast(int)(t);

            if( index >= 0 &&
                index < strings.length &&
                strings[index].value == index)
            {
                return strings[index].str;
            }

            // Otherwise, just do a linear search
            foreach(EnumString s; strings)
            {
                if(cast(int)(t) == s.value)
                {
                    return s.str;
                }
            }

            return "<unknown>";
        }
    }

    /*
 /////////////////////////////////////////////////////////////////////////////
     * Enumerations
     */

    /** Flags that moderate the creation of Databases */
    public enum ORJ_FLAG
    {
            ORDER_FIELDS                    =   0x0001  /*!< 
 Arranges the
 fields in alphabetical order                  */
        ,   ELIDE_BLANK_RECORDS             =   0x0002  /*!< Causes 
 blank
 records to be ignored                         */
    }

    public char[] toString(ORJ_FLAG f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_FLAG.ORDER_FIELDS,           "Arranges the 
 fields
 in alphabetical order" }
            ,   {   ORJ_FLAG.ELIDE_BLANK_RECORDS,    "Causes blank
 records
 to be ignored"        }
        ];

        return enum_to_string!(ORJ_FLAG)(strings, f);
    }

    /** General error codes */
    public enum ORJRC
    {
            SUCCESS                      =   0          /*!< 
 Operation
 was
 successful                                   */
        ,   CANNOT_OPEN_JAR_FILE                        /*!< The 
 given
 file
 does not exist, or cannot be accessed       */
        ,   NO_RECORDS                                  /*!< The 
 database
 file contained no records                     */
        ,   OUT_OF_MEMORY                               /*!< The 
 API
 suffered memory exhaustion                         */
        ,   BAD_FILE_READ                               /*!< A read
 operation failed                                    */
        ,   PARSE_ERROR                                 /*!< 
 Parsing of
 the
 database file failed due to a syntax error  */
        ,   INVALID_INDEX                               /*!< An 
 invalid
 index was specified                             */
        ,   UNEXPECTED                                  /*!< An
 unexpected
 condition was encountered                    */
        ,   INVALID_CONTENT                             /*!< The 
 database
 file contained invalid content                */
    }

    public char[] toString(ORJRC f)
    {
        const EnumString    strings[] =
        [
                {   ORJRC.SUCCESS,              "Operation was
             }
            ,   {   ORJRC.CANNOT_OPEN_JAR_FILE, "The given file 
 does not
 exist, or cannot be accessed"          }
            ,   {   ORJRC.NO_RECORDS,           "The database file
 contained no records"                        }
            ,   {   ORJRC.OUT_OF_MEMORY,        "The API suffered 
 memory
 exhaustion"                            }
            ,   {   ORJRC.BAD_FILE_READ,        "A read operation
         }
            ,   {   ORJRC.PARSE_ERROR,          "Parsing of the 
 database
 file failed due to a syntax error"     }
            ,   {   ORJRC.INVALID_INDEX,        "An invalid index 
 was
 specified"                                }
            ,   {   ORJRC.UNEXPECTED,           "An unexpected 
 condition
 was encountered"                       }
            ,   {   ORJRC.INVALID_CONTENT,      "The database file
 contained invalid content"                   }
        ];

        return enum_to_string!(ORJRC)(strings, f);
    }

    /** Parsing error codes */
    public enum ORJ_PARSE_ERROR
    {
            SUCCESS                         =   0       /*!< 
 Parsing was
 successful 
 */
        ,   RECORD_SEPARATOR_IN_CONTINUATION            /*!< A 
 record
 separator was encountered during a content line continuation */
        ,   UNFINISHED_LINE                             /*!< The 
 last
 line
 in the database was not terminated by a line-feed 
 */
        ,   UNFINISHED_FIELD                            /*!< The 
 last
 field
 in the database file was not terminated by a record separator   */
        ,   UNFINISHED_RECORD                           /*!< The 
 last
 record in the database file was not terminated by a record 
 separator */
    }

    public char[] toString(ORJ_PARSE_ERROR f)
    {
        const EnumString    strings[] =
        [
                {   ORJ_PARSE_ERROR.SUCCESS, "Parsing was }
            ,   { 
 ORJ_PARSE_ERROR.RECORD_SEPARATOR_IN_CONTINUATION, "A
 record separator was encountered during a content line }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_LINE, "The last line 
 in
 the
 database was not terminated by a }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_FIELD, "The last 
 field in
 the database file was not terminated by a record separator"  }
            ,   {   ORJ_PARSE_ERROR.UNFINISHED_RECORD, "The last 
 record
 in
 the database file was not terminated by a record separator" }
        ];

        return enum_to_string!(ORJ_PARSE_ERROR)(strings, f);
    }





Mar 10 2005
prev sibling parent reply "Andrew Fedoniouk" <news terrainformatica.com> writes:
enum E {
  FIRST = 0x01,
  SECOND =  0x02 ,
  THIRD =  0x04
}

alias char[] string8;

string8 toString(E e)
{
  static string8[int] map; if(!map.length)
  {
    map[E.FIRST] = "first";
    map[E.SECOND]  = "second";
    map[E.THIRD] = "third one";
  }
  return map[e];
}

Huh?

Andrew. 
Mar 09 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
"Andrew Fedoniouk" <news terrainformatica.com> wrote in message 
news:d0oodt$1ba0$1 digitaldaemon.com...
 enum E {
  FIRST = 0x01,
  SECOND =  0x02 ,
  THIRD =  0x04
 }

 alias char[] string8;

 string8 toString(E e)
 {
  static string8[int] map; if(!map.length)
  {
    map[E.FIRST] = "first";
    map[E.SECOND]  = "second";
    map[E.THIRD] = "third one";
  }
  return map[e];
 }

 Huh?

It's going to use more memory, though it's only a bit. It allocates memory at runtime, with the consequent, though unlikely, possibility of being out of memory It's going to run slower, though it's only a bit. Linear searches are generally more efficient for small data sets, which most enums are. It doesn't optimise for the common case where an enum value is equal to its index. It doesn't handle the case where the value is unrecognised, though that could be added by using some horrible 'in' construction. All these are small matters, to be sure, but are persuasive, at least to me. Please note: the solution I gave is what I would hope would become built-in. In that case it's only drawback, its verbosity, would be moot.
Mar 10 2005
parent reply "Andrew Fedoniouk" <news terrainformatica.com> writes:
"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message 
news:d0p18e$1l2q$1 digitaldaemon.com...
 "Andrew Fedoniouk" <news terrainformatica.com> wrote in message 
 news:d0oodt$1ba0$1 digitaldaemon.com...
 enum E {
  FIRST = 0x01,
  SECOND =  0x02 ,
  THIRD =  0x04
 }

 alias char[] string8;

 string8 toString(E e)
 {
  static string8[int] map; if(!map.length)
  {
    map[E.FIRST] = "first";
    map[E.SECOND]  = "second";
    map[E.THIRD] = "third one";
  }
  return map[e];
 }

 Huh?

It's going to use more memory, though it's only a bit. It allocates memory at runtime, with the consequent, though unlikely, possibility of being out of memory

Yes, it is. See below.
 It's going to run slower, though it's only a bit. Linear searches are 
 generally more efficient for small data sets, which most enums are.

Well, it depends on implementation of assoc. map in D. It could be an adaptive hash map which is either simple list if number of items is less than threshold and a real hasmap otherwise. But in D as far as I can see assosiative arrays made as lookup binary trees. So they are not so much expensive for small sets - but not so effective on big sets - reasonable compromise for built-ins. For small sets D's AA is close to linear search,
 It doesn't optimise for the common case where an enum value is equal to 
 its index.

Yes, but I've provided another implementation for "consequent" enums.
 It doesn't handle the case where the value is unrecognised, though that 
 could be added by using some horrible 'in' construction.

Life is life.
 All these are small matters, to be sure, but are persuasive, at least to 
 me.

 Please note: the solution I gave is what I would hope would become 
 built-in. In that case it's only drawback, its verbosity, would be moot.

Built-in.... Do you mean they will be implemented inside D compiler/runtime by default? If yes this is absolutely another case. 1) I don't want *all* enums to be "stringizeable" this way. 2) I would like to be able to define different string sets for different locales for the same enum. For me personally it would be enough to have hash map static initializers - static hash maps. They can be implenmented using (Minimal) Perfect Hash similar to what gnu::gperf.exe does - this is not the must but desirable. int[char[]] m = { "one":1, "two":2 } char[][int] m = { 1:"one", 2: "two" }
Mar 10 2005
parent "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
 Built-in.... Do you mean they will be implemented inside D 
 compiler/runtime by default?
 If yes this is absolutely another case.

That's what I'd like, as a default
 1) I don't want *all* enums to be "stringizeable" this way.

That'd be easy. Just don't provide any strings! :-)
 2) I would like to be able to define different string sets for 
 different locales for the same enum.

Agreed. The only way it'd be 'default' would be if one provided strings within the definition, as in: enum E1 { val1 : "This represents something" , val2 : "This represents something else" } enum E2 { val3 , val4 } enum E3 { val5 , val6 } char[] toString(E3 e); // Your localisation-aware implementation E1 e1 = E1.val1; E2 e2 = E2.val4; E3 e3 = E3.val5; char[] s1 = toString(e1); // This would use the compiler generated version, with the same impl as I've provided explicitly char[] s2 = toString(e2); // This would be a compilation error, since E2 does not have one provided char[] s3 = toString(e3); // Calls the explicitly provided function
 For me personally it would be enough to have hash map static 
 initializers - static hash maps.
 They can be implenmented using (Minimal) Perfect Hash similar to what 
 gnu::gperf.exe
 does - this is not the must but desirable.

 int[char[]] m = { "one":1, "two":2 }
 char[][int] m = { 1:"one", 2: "two" }

I think that's a separate issue, but I agree we should be able to have them
Mar 10 2005
prev sibling parent reply Jason Mills <jmills cs.mun.ca> writes:
Maybe D should have enums that are Java-like. See
http://java.sun.com/j2se/1.5.0/docs/guide/language/enums.html

Jason

Matthew wrote:
 Just thought I'd share what I came up with for the enum => string stuff, 
 which is currently resident in std/openrj.d. If it receives a +ve 
 reaction we can move it into somewhere common, and use it for all enums. 
 (That's assuming, of course, we don't get something in the language to 
 do it for us.)
 

Mar 10 2005
parent =?ISO-8859-1?Q?Anders_F_Bj=F6rklund?= <afb algonet.se> writes:
Jason Mills wrote:

 Maybe D should have enums that are Java-like. See
 http://java.sun.com/j2se/1.5.0/docs/guide/language/enums.html

You mean classes ? But if strings and arrays are not classes in D, then why should enumerations be ? Heck, sometimes not even classes are classes in D (!) - but just structs, for performance reasons ? I think this could be solved with better TypeInfo and some props... Like digitalmars.D/12594 (from the http://www.prowiki.org/wiki4d/wiki.cgi?FeatureRequestList) --anders
Mar 10 2005