Does D have a native function to capitalize only the first letter of the word? (I'm asking that so I might avoid reinvent the wheel, which I did sometimes in D)

Marc wrote:

> Does D have a native function to capitalize only the first letter of the word? (I'm asking that so I might avoid reinvent the wheel, which I did sometimes in D)

http://dpldocs.info/experimental-docs/std.string.capitalize.html
http://dpldocs.info/experimental-docs/std.uni.asCapitalized.html

searching rox!

p.s.: but beware, it will lowercase all the letters except the first one, so it may not be exactly the thing you aksed for.

Something like this: https://dlang.org/phobos/std_uni.html#asCapitalized

On Tue, Dec 5, 2017 at 2:31 PM, Marc via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com> wrote:

> Does D have a native function to capitalize only the first letter of the word? (I'm asking that so I might avoid reinvent the wheel, which I did sometimes in D)
>

but this will change all other uppercase to lowercase, so maybe it is not what you want. If you really want just change first char to upper, then there is nothing wrong to do it yourself

On Tue, Dec 5, 2017 at 2:37 PM, Daniel Kozak <kozzi11@gmail.com> wrote:

> Something like this: https://dlang.org/phobos/std_uni.html#asCapitalized
>
> On Tue, Dec 5, 2017 at 2:31 PM, Marc via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com> wrote:
>
>> Does D have a native function to capitalize only the first letter of the word? (I'm asking that so I might avoid reinvent the wheel, which I did sometimes in D)
>>
>
>

On Tuesday, 5 December 2017 at 13:40:08 UTC, Daniel Kozak wrote:
> but this will change all other uppercase to lowercase, so maybe it is not what you want. If you really want just change first char to upper, then there is nothing wrong to do it yourself
>
> On Tue, Dec 5, 2017 at 2:37 PM, Daniel Kozak <kozzi11@gmail.com> wrote:
>
>> Something like this: https://dlang.org/phobos/std_uni.html#asCapitalized
>>
>> On Tue, Dec 5, 2017 at 2:31 PM, Marc via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com> wrote:
>>
>>> Does D have a native function to capitalize only the first letter of the word? (I'm asking that so I might avoid reinvent the wheel, which I did sometimes in D)

Yes, this is not what I want. I want to convert only the first letter of the word to lower case and left all the others immutable. similar to PHP's lcfirst():

http://php.net/manual/en/function.lcfirst.php

On Tuesday, 5 December 2017 at 14:01:35 UTC, Marc wrote:
> On Tuesday, 5 December 2017 at 13:40:08 UTC, Daniel Kozak wrote:
>> but this will change all other uppercase to lowercase, so maybe it is not what you want. If you really want just change first char to upper, then there is nothing wrong to do it yourself
>>
>> On Tue, Dec 5, 2017 at 2:37 PM, Daniel Kozak <kozzi11@gmail.com> wrote:
>>
>>> Something like this: https://dlang.org/phobos/std_uni.html#asCapitalized
>>>
>>> On Tue, Dec 5, 2017 at 2:31 PM, Marc via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com> wrote:
>>>
>>>> Does D have a native function to capitalize only the first letter of the word? (I'm asking that so I might avoid reinvent the wheel, which I did sometimes in D)
>
> Yes, this is not what I want. I want to convert only the first letter of the word to lower case and left all the others immutable. similar to PHP's lcfirst():
>
> http://php.net/manual/en/function.lcfirst.php

this is how i'd do it:

string upcaseFirst(string wut) {
  import std.ascii : toUpper;
  import std.array : appender;

  auto s = appender!string;
  s ~= wut[0].toUpper;
  s ~= wut[1..$];
  return s.data;
}

On Tuesday, 5 December 2017 at 14:34:57 UTC, Mengu wrote:
> On Tuesday, 5 December 2017 at 14:01:35 UTC, Marc wrote:
>> On Tuesday, 5 December 2017 at 13:40:08 UTC, Daniel Kozak wrote:
>>>>> [...]
>>
>> Yes, this is not what I want. I want to convert only the first letter of the word to lower case and left all the others immutable. similar to PHP's lcfirst():
>>
>> http://php.net/manual/en/function.lcfirst.php
>
> this is how i'd do it:
>
> string upcaseFirst(string wut) {
>   import std.ascii : toUpper;
>   import std.array : appender;
>
>   auto s = appender!string;
>   s ~= wut[0].toUpper;
>   s ~= wut[1..$];
>   return s.data;
> }

however a solution that does not allocate any memory would be a lot better.

On 2017-12-05 15:34, Mengu wrote:

> this is how i'd do it:
> 
> string upcaseFirst(string wut) {
>    import std.ascii : toUpper;
>    import std.array : appender;
> 
>    auto s = appender!string;
>    s ~= wut[0].toUpper;
>    s ~= wut[1..$];
>    return s.data;
> }

That's not Unicode aware and is only safe to do with single byte characters.

-- 
/Jacob Carlborg

On 12/5/17 10:00 AM, Mengu wrote:
> On Tuesday, 5 December 2017 at 14:34:57 UTC, Mengu wrote:
>> On Tuesday, 5 December 2017 at 14:01:35 UTC, Marc wrote:
>>> On Tuesday, 5 December 2017 at 13:40:08 UTC, Daniel Kozak wrote:
>>>>>> [...]
>>>
>>> Yes, this is not what I want. I want to convert only the first letter of the word to lower case and left all the others immutable. similar to PHP's lcfirst():
>>>
>>> http://php.net/manual/en/function.lcfirst.php
>>
>> this is how i'd do it:
>>
>> string upcaseFirst(string wut) {
>>   import std.ascii : toUpper;
>>   import std.array : appender;
>>
>>   auto s = appender!string;
>>   s ~= wut[0].toUpper;
>>   s ~= wut[1..$];
>>   return s.data;
>> }
> 
> however a solution that does not allocate any memory would be a lot better.

Non-allocating version:

struct LowerCaseFirst(R) // if(isSomeString!R)
{
   R src;
   bool notFirst; // terrible name, but I want default false
   dchar front() {
      import std.uni: toLower;
      return notFirst ? src.front : src.front.toLower;
   }
   void popFront() { notFirst = true; src.popFront; }
   bool empty() { return src.empty; }
}

auto lowerCaseFirst(R)(R r)
{
   return LowerCaseFirst!R(r);
}

Warning: it ain't going to be fast. Auto-decoding everywhere.

-Steve

On 12/05/2017 09:25 AM, Steven Schveighoffer wrote:

> Non-allocating version:
> 
> struct LowerCaseFirst(R) // if(isSomeString!R)
> {
>     R src;
>     bool notFirst; // terrible name, but I want default false
>     dchar front() {
>        import std.uni: toLower;
>        return notFirst ? src.front : src.front.toLower;
>     }
>     void popFront() { notFirst = true; src.popFront; }
>     bool empty() { return src.empty; }
> }
> 
> auto lowerCaseFirst(R)(R r)
> {
>     return LowerCaseFirst!R(r);
> }
> 
> Warning: it ain't going to be fast. Auto-decoding everywhere.
> 
> -Steve

One using existing facilities:

import std.range;
import std.uni;
import std.algorithm;

auto lowerCaseFirst(R)(R r) {
    R rest = r.save;
    rest.popFront();
    return chain(r.front.toLower.only, rest);
}

unittest {
    assert(lowerCaseFirst("SchveiGoffer").equal("schveiGoffer"));
    assert(lowerCaseFirst("ŞchveıĞöffer").equal("şchveıĞöffer"));
}

void main() {
}

Ali