added support for multiple comment characters

By default, it will now use '/!#'. Fixes #456

Author: jacobwilliams

src/json_initialize_arguments.inc

@@ -32,13 +32,13 @@ logical(LK),intent(in),optional :: unescape_strings
   !! string is returned from [[json_get_string]]
   !! and similar routines. If true [default],
   !! then the string is returned unescaped.
-character(kind=CK,len=1),intent(in),optional :: comment_char
-  !! If present, this character is used
+character(kind=CK,len=*),intent(in),optional :: comment_char
+  !! If present, these characters are used
   !! to denote comments in the JSON file,
   !! which will be ignored if present.
-  !! Example: `!` or `#`. Setting this
+  !! Example: `!`, `#`, or `/!#`. Setting this
   !! to a blank string disables the
-  !! ignoring of comments. (Default is `!`).
+  !! ignoring of comments. (Default is `/!#`).
 integer(IK),intent(in),optional :: path_mode
   !! How the path strings are interpreted in the
   !! `get_by_path` routines:

src/json_value_module.F90

@@ -216,11 +216,12 @@ module json_value_module
                                                    !! then the string is returned unescaped.
 
         logical(LK) :: allow_comments = .true.  !! if true, any comments will be ignored when
-                                                !! parsing a file. The comment token is defined
+                                                !! parsing a file. The comment tokens are defined
                                                 !! by the `comment_char` character variable.
-        character(kind=CK,len=1) :: comment_char = CK_'!'  !! comment token when
-                                                           !! `allow_comments` is true.
-                                                           !! Examples: '`!`' or '`#`'.
+        character(kind=CK,len=:),allocatable :: comment_char !! comment tokens when
+                                                             !! `allow_comments` is true.
+                                                             !! Examples: '`!`' or '`#`'.
+                                                             !! Default is `CK_'/!#'`.
 
         integer(IK) :: path_mode = 1_IK  !! How the path strings are interpreted in the
                                          !! `get_by_path` routines:
@@ -1081,7 +1082,7 @@ subroutine json_initialize(me,&
     ! [an empty string disables comments]
     if (present(comment_char)) then
         me%allow_comments = comment_char/=CK_''
-        me%comment_char = comment_char
+        me%comment_char = trim(adjustl(comment_char))
     end if
 
     ! path separator:
@@ -9736,6 +9737,12 @@ subroutine json_parse_file(json, file, p, unit)
     ! clear any exceptions and initialize:
     call json%initialize()
 
+    if (json%allow_comments .and. .not. allocated(json%comment_char)) then
+        ! comments are enabled, but user hasn't set the comment char,
+        ! so in this case use the default:
+        json%comment_char = CK_'/!#'
+    end if
+
     if ( present(unit) ) then
 
         if (unit==0) then
@@ -9846,6 +9853,12 @@ subroutine json_parse_string(json, p, str)
     ! clear any exceptions and initialize:
     call json%initialize()
 
+    if (json%allow_comments .and. .not. allocated(json%comment_char)) then
+        ! comments are enabled, but user hasn't set the comment char,
+        ! so in this case use the default:
+        json%comment_char = CK_'/!#'
+    end if
+
     ! create the value and associate the pointer
     call json_value_create(p)
 
@@ -11435,7 +11448,7 @@ subroutine pop_char(json,unit,str,skip_ws,skip_comments,eof,popped)
 
             end if
 
-            if (ignore_comments .and. (parsing_comment .or. c == json%comment_char) ) then
+            if (ignore_comments .and. (parsing_comment .or. scan(c,json%comment_char,kind=IK)>0_IK) ) then
 
                 ! skipping the comment
                 parsing_comment = .true.