bug#66614: 29.1.50; Support not capitalizing words inside symbols

[Eli Zaretskii <eliz@gnu.org>]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Date: Wed, 18 Oct 2023 13:01:43 -0400
> 
> --- a/doc/lispref/strings.texi
> +++ b/doc/lispref/strings.texi
> @@ -1510,7 +1510,9 @@ Case Conversion
>  
>  The definition of a word is any sequence of consecutive characters that
>  are assigned to the word constituent syntax class in the current syntax
> -table (@pxref{Syntax Class Table}).
> +table (@pxref{Syntax Class Table}), or if @var{case-symbols-as-words} is
> +non-nil, also characters assigned to the symbol constituent syntax
> +class.
>  
>  When @var{string-or-char} is a character, this function does the same
>  thing as @code{upcase}.
> @@ -1542,7 +1544,9 @@ Case Conversion
>  
>  The definition of a word is any sequence of consecutive characters that
>  are assigned to the word constituent syntax class in the current syntax
> -table (@pxref{Syntax Class Table}).
> +table (@pxref{Syntax Class Table}), or if @var{case-symbols-as-words} is
> +non-nil, also characters assigned to the symbol constituent syntax
> +class.

These two hunks use @var incorrectly: case-symbols-as-words is a
literal symbol, so it should have the @code markup.

> ++++
> +** New variable 'case-symbols-as-words' to change case behavior for symbols.

"Case behavior" is confusing.  I think you mean

  New variable 'case-symbols-as-words' affects case operations for symbols.

> +If this is set to non-nil, then case operations such as
> +'upcase-initials' or 'replace-match' (with nil FIXEDCASE) will treat
> +symbol constituents as if they were part of words.

Don't you mean

  will treat the entire symbol name as a single word

?  I find the text you used confusing, FWIW.

>                                                    This is useful for
> +programming languages and style where words in the middle of symbols
> +are never capitalized.

Likewise here: instead of talking about "words in the middle of
symbols", wouldn't it be better to say something like

  ...style where only the first letter of a symbol's name is ever
  capitalized.

?

Also, please say here that the default of this new variable is nil.

> +  DEFVAR_BOOL ("case-symbols-as-words", case_symbols_as_words,
> +	       doc: /* If non-nil, case functions treat symbol syntax as part of words.
> +
> +Functions such as `upcase-initials' and `replace-match' check or modify
> +the case pattern of sequences of characters.  Normally, these operate on
> +sequences of characters whose syntax is word constituent.  If this
> +variable is non-nil, then they operate on sequences of characters who
> +syntax is either word constituent or symbol constituent.
> +
> +This is useful for programming styles which wish to capitalize the
> +beginning of symbols, but not capitalize individual words in a symbol.*/);

Similar comments about this doc string.

Also, shouldn't this variable be buffer-local?  You want certain major
modes to set it, right?

> -	      if (SYNTAX (prevc) != Sword)
> +	      if (SYNTAX (prevc) != Sword
> +		  && (!case_symbols_as_words || SYNTAX (prevc) != Ssymbol))

I think the code will be more clear if you use

		  && !(case_symbols_as_words && SYNTAX (prevc) == Ssymbol))

>  	  else if (uppercasep (c))
>  	    {
>  	      some_uppercase = 1;
> -	      if (SYNTAX (prevc) != Sword)
> +	      if (SYNTAX (prevc) != Sword
> +		  && (!case_symbols_as_words || SYNTAX (prevc) != Ssymbol))

Same here.

>  	      /* If the initial is a caseless word constituent,
>  		 treat that like a lowercase initial.  */
> -	      if (SYNTAX (prevc) != Sword)
> +	      if (SYNTAX (prevc) != Sword
> +		  && (!case_symbols_as_words || SYNTAX (prevc) != Ssymbol))
>  		some_nonuppercase_initial = 1;

And here.

Thanks.