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digitalmars.D.learn - String "dequote" in phobos?

reply cc <cc nevernet.com> writes:
Does something to dequote (unquote? or what would you call it?) a 
string exist in the standard library?  I didn't see one in 
std.string, just wondering before reinventing the wheel.

Something like:
```d
assert(dequote(`"foo"`) == "foo");
assert(dequote(`'foo'`) == "foo");
assert(dequote(`"foo's"`) == "foo's");
assert(dequote(`'foo "bar"'`) == `foo "bar"`);
assert(dequote(`"fo\"o"`) == `fo"o`);
dequote(`"fo"o"`); // bad quoting, maybe throw an exception here 
or something?
```
May 13 2021
next sibling parent Paul Backus <snarwin gmail.com> writes:
On Thursday, 13 May 2021 at 14:10:08 UTC, cc wrote:

 Does something to dequote (unquote? or what would you call it?) 
 a string exist in the standard library?  I didn't see one in 
 std.string, just wondering before reinventing the wheel.

 Something like:
 ```d
 assert(dequote(`"foo"`) == "foo");
 assert(dequote(`'foo'`) == "foo");
 assert(dequote(`"foo's"`) == "foo's");
 assert(dequote(`'foo "bar"'`) == `foo "bar"`);
 assert(dequote(`"fo\"o"`) == `fo"o`);
 dequote(`"fo"o"`); // bad quoting, maybe throw an exception 
 here or something?
 ```


I don't think there's anything like this in the standard library. 
If you write your own, consider publishing it on code.dlang.org.
May 13 2021
prev sibling next sibling parent reply Imperatorn <johan_forsberg_86 hotmail.com> writes:
On Thursday, 13 May 2021 at 14:10:08 UTC, cc wrote:

 Does something to dequote (unquote? or what would you call it?) 
 a string exist in the standard library?  I didn't see one in 
 std.string, just wondering before reinventing the wheel.

 Something like:
 ```d
 assert(dequote(`"foo"`) == "foo");
 assert(dequote(`'foo'`) == "foo");
 assert(dequote(`"foo's"`) == "foo's");
 assert(dequote(`'foo "bar"'`) == `foo "bar"`);
 assert(dequote(`"fo\"o"`) == `fo"o`);
 dequote(`"fo"o"`); // bad quoting, maybe throw an exception 
 here or something?
 ```


Wouldn't this just this do that? 🤔

```d
string dequote(string s)
{
     return s[1..$-1];
}
```
May 13 2021
next sibling parent cc <cc nevernet.com> writes:
On Thursday, 13 May 2021 at 16:40:29 UTC, Imperatorn wrote:

 Wouldn't this just this do that? 🤔

 ```d
 string dequote(string s)
 {
     return s[1..$-1];
 }
 ```


The idea would be for situations where it isn't known in advance 
whether the string is quoted, if it is quoted properly, and 
whether there are escaped quotes within the string that need to 
be un-escaped.  Additionally some data sources may handle 
escaping quotes in strings differently (e.g. `\"` vs `""`)
May 13 2021
prev sibling parent reply kdevel <kdevel vogtner.de> writes:
On Thursday, 13 May 2021 at 16:40:29 UTC, Imperatorn wrote:

 Wouldn't this just this do that? 🤔

 ```d
 string dequote(string s)
 {
     return s[1..$-1];
 }
 ```


1. Your code throws Range errors if s.length < 2.
2. assert(dequote(`"fo\"o"`) == `fo"o`) fails
3. dequote(`"fo"o"`) does not throw.
May 13 2021
parent Imperatorn <johan_forsberg_86 hotmail.com> writes:
On Thursday, 13 May 2021 at 17:13:40 UTC, kdevel wrote:

 On Thursday, 13 May 2021 at 16:40:29 UTC, Imperatorn wrote:

 Wouldn't this just this do that? 🤔

 ```d
 string dequote(string s)
 {
     return s[1..$-1];
 }
 ```


 1. Your code throws Range errors if s.length < 2.
 2. assert(dequote(`"fo\"o"`) == `fo"o`) fails
 3. dequote(`"fo"o"`) does not throw.


WI spent 2 seconds thinking about it and 18 seconds typing on my 
phone so I'm not so surprised it didn't work. It did "Ok" for a 
20 sec attempt tho 😁
May 13 2021
prev sibling parent Anonymouse <zorael gmail.com> writes:
On Thursday, 13 May 2021 at 14:10:08 UTC, cc wrote:

 Does something to dequote (unquote? or what would you call it?) 
 a string exist in the standard library?  I didn't see one in 
 std.string, just wondering before reinventing the wheel.

 Something like:
 ```d
 assert(dequote(`"foo"`) == "foo");
 assert(dequote(`'foo'`) == "foo");
 assert(dequote(`"foo's"`) == "foo's");
 assert(dequote(`'foo "bar"'`) == `foo "bar"`);
 assert(dequote(`"fo\"o"`) == `fo"o`);
 dequote(`"fo"o"`); // bad quoting, maybe throw an exception 
 here or something?
 ```


I called mine `unquoted`[1] and `unsinglequoted`. Not very 
imaginative, I concede.

I also assumed ASCII and fearlessly sliced `line[1..$-1]`, which 
you may or may not be able to do.

```d
private T unenclosed(char token = '"', T)(const T line) pure 
nothrow  nogc
if (isSomeString!T)
{
     enum escaped = "\\" ~ token;

     if (line.length < 2)
     {
         return line;
     }
     else if ((line[0] == token) && (line[$-1] == token))
     {
         if ((line.length >= 3) && (line[$-2..$] == escaped))
         {
             // End quote is escaped
             return line;
         }

         return line[1..$-1].unenclosed!token;
     }
     else
     {
         return line;
     }
}


pragma(inline, true)
T unquoted(T)(const T line) pure nothrow  nogc
{
     return unenclosed!'"'(line);
}

unittest
{
     assert(`"Lorem ipsum sit amet"`.unquoted == "Lorem ipsum sit 
amet");
     assert(`"""""Lorem ipsum sit amet"""""`.unquoted == "Lorem 
ipsum sit amet");
     // Unbalanced quotes are left untouched
     assert(`"Lorem ipsum sit amet`.unquoted == `"Lorem ipsum sit 
amet`);
     assert(`"Lorem \"`.unquoted == `"Lorem \"`);
     assert("\"Lorem \\\"".unquoted == "\"Lorem \\\"");
     assert(`"\"`.unquoted == `"\"`);
}


pragma(inline, true)
T unsinglequoted(T)(const T line) pure nothrow  nogc
{
     return unenclosed!'\''(line);
}

// ...
```

I'm not sure it's quite correct for all valid inputs but it 
worked well enough for my purposes.

[1]: http://lu.dpldocs.info/lu.string.unquoted.html
May 13 2021