digitalmars.D.learn - Is there a reason for default-int?
- "Simen kjaeraas" <simen.kjaras gmail.com> Dec 28 2009
- "Phil Deets" <pjdeets2 gmail.com> Dec 28 2009
- Don <nospam nospam.com> Dec 28 2009
- Ary Borenszweig <ary esperanto.org.ar> Dec 29 2009
- BCS <none anon.com> Dec 29 2009
- Don <nospam nospam.com> Dec 29 2009
- Ary Borenszweig <ary esperanto.org.ar> Dec 30 2009
- BCS <none anon.com> Dec 31 2009
- Don <nospam nospam.com> Dec 28 2009
- BCS <none anon.com> Dec 29 2009
- "Simen kjaeraas" <simen.kjaras gmail.com> Dec 29 2009
Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense? -- Simen
Dec 28 2009
On Mon, 28 Dec 2009 16:18:46 -0500, Simen kjaeraas = <simen.kjaras gmail.com> wrote:Apart from C legacy, is there a reason to assume anything we don't kno=
what is, is an int? Shouldn't the compiler instead say 'unknown type' or =
something else that makes sense?
C++ abandoned default int. I think it would be best for D to do the same= . Just my 2=A2, Phil Deets
Dec 28 2009
Phil Deets wrote:On Mon, 28 Dec 2009 16:18:46 -0500, Simen kjaeraas <simen.kjaras gmail.com> wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
C++ abandoned default int. I think it would be best for D to do the same.
D never had default int. When there's an error, the compiler just has to choose *some* type, so that it doesn't crash <g>.
Dec 28 2009
Don wrote:Phil Deets wrote:On Mon, 28 Dec 2009 16:18:46 -0500, Simen kjaeraas <simen.kjaras gmail.com> wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
C++ abandoned default int. I think it would be best for D to do the same.
D never had default int. When there's an error, the compiler just has to choose *some* type, so that it doesn't crash <g>.
It could be an Error type (that's not an alias for int type) that don't start to spit errors everywhere and instead just blocks all further errors on that type.
Dec 29 2009
Hello Ary,Don wrote:Phil Deets wrote:On Mon, 28 Dec 2009 16:18:46 -0500, Simen kjaeraas <simen.kjaras gmail.com> wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
same.
to choose *some* type, so that it doesn't crash <g>.
don't start to spit errors everywhere and instead just blocks all further errors on that type.
that poses an interesting question: what "type" does this this give? int i; char[] s; int foo(int); char[] foo(int,char[]); int[] foo(char[],int); auto whatType = foo(i ~ s, s); i~s gives the error type but DMD could tell that as long as the other args are correct, the only foo that works returns a char[] so does the variable get the error type or char[]?
Dec 29 2009
BCS wrote:Hello Ary,Don wrote:Phil Deets wrote:On Mon, 28 Dec 2009 16:18:46 -0500, Simen kjaeraas <simen.kjaras gmail.com> wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
same.
to choose *some* type, so that it doesn't crash <g>.
don't start to spit errors everywhere and instead just blocks all further errors on that type.
that poses an interesting question: what "type" does this this give? int i; char[] s; int foo(int); char[] foo(int,char[]); int[] foo(char[],int); auto whatType = foo(i ~ s, s); i~s gives the error type but DMD could tell that as long as the other args are correct, the only foo that works returns a char[] so does the variable get the error type or char[]?
Dec 29 2009
Don wrote:BCS wrote:Hello Ary,Don wrote:Phil Deets wrote:On Mon, 28 Dec 2009 16:18:46 -0500, Simen kjaeraas <simen.kjaras gmail.com> wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
same.
to choose *some* type, so that it doesn't crash <g>.
don't start to spit errors everywhere and instead just blocks all further errors on that type.
that poses an interesting question: what "type" does this this give? int i; char[] s; int foo(int); char[] foo(int,char[]); int[] foo(char[],int); auto whatType = foo(i ~ s, s); i~s gives the error type but DMD could tell that as long as the other args are correct, the only foo that works returns a char[] so does the variable get the error type or char[]?
Exactly! You would get an error saying "i ~ s" cannot happen, then it resolves to the Error type. Now resolution of "foo" is not done (or yes: it defaults to Error) because it has an argument of type Error (one less error in the console is shown). Since foo is error, whatType is Error. Then if whatType is used it won't trigger errors. Etc. You would get a single error in the precise position you need to correct it, instead of one error hidden with other many unrelated errors.
Dec 30 2009
BCS <none anon.com> Hello Ary,Don wrote:BCS wrote:Hello Ary,Don wrote:Phil Deets wrote:On Mon, 28 Dec 2009 16:18:46 -0500, Simen kjaeraas <simen.kjaras gmail.com> wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
the same.
has to choose *some* type, so that it doesn't crash <g>.
don't start to spit errors everywhere and instead just blocks all further errors on that type.
int i; char[] s; int foo(int); char[] foo(int,char[]); int[] foo(char[],int); auto whatType = foo(i ~ s, s); i~s gives the error type but DMD could tell that as long as the other args are correct, the only foo that works returns a char[] so does the variable get the error type or char[]?
resolves to the Error type. Now resolution of "foo" is not done (or yes: it defaults to Error) because it has an argument of type Error (one less error in the console is shown). Since foo is error, whatType is Error. Then if whatType is used it won't trigger errors. Etc. You would get a single error in the precise position you need to correct it, instead of one error hidden with other many unrelated errors.
IIRC, all of the above is planned and in the works. The only point I was wondering about is should DMD attempt to resolve functions where args are of error types? My thought is that in some cases it could resolve it and detect real errors down the line. OTOH, the argument for this (that blind propagation of Error can disable type checking on large swaths of code, even across functions via template code and auto return) is also an argument for why it could be a disaster if it makes the wrong guess.
Dec 31 2009
Simen kjaeraas wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
There's now an Error type in the compiler. It's gradually filtering its way through the compiler.
Dec 28 2009
Hello Don,Simen kjaeraas wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
its way through the compiler.
ok. Can we s/gradually/rapidly/ ?
Dec 29 2009
On Tue, 29 Dec 2009 07:37:42 +0100, Don <nospam nospam.com> wrote:Simen kjaeraas wrote:Apart from C legacy, is there a reason to assume anything we don't know what is, is an int? Shouldn't the compiler instead say 'unknown type' or something else that makes sense?
There's now an Error type in the compiler. It's gradually filtering its way through the compiler.
Great! -- Simen
Dec 29 2009