main: Add ' helper function

Author: phy1729

docs/highlighters/main.md

@@ -38,6 +38,7 @@ This highlighter defines the following styles:
 * `single-quoted-argument` - single quoted arguments (`` 'foo' ``)
 * `double-quoted-argument` - double quoted arguments (`` "foo" ``)
 * `dollar-quoted-argument` - dollar quoted arguments (`` $'foo' ``)
+* `rc-quote` - two single quotes inside single quotes when `RC_QUOTES` is set (`` 'foo''bar' ``)
 * `dollar-double-quoted-argument` - parameter expansion inside double quotes (`$foo` inside `""`)
 * `back-double-quoted-argument` -  back double quoted arguments (`\x` inside `""`)
 * `back-dollar-quoted-argument` -  back dollar quoted arguments (`\x` inside `$''`)

highlighters/main/main-highlighter.zsh

@@ -46,6 +46,7 @@
 : ${ZSH_HIGHLIGHT_STYLES[single-quoted-argument]:=fg=yellow}
 : ${ZSH_HIGHLIGHT_STYLES[double-quoted-argument]:=fg=yellow}
 : ${ZSH_HIGHLIGHT_STYLES[dollar-quoted-argument]:=fg=yellow}
+: ${ZSH_HIGHLIGHT_STYLES[rc-quote]:=fg=cyan}
 : ${ZSH_HIGHLIGHT_STYLES[dollar-double-quoted-argument]:=fg=cyan}
 : ${ZSH_HIGHLIGHT_STYLES[back-double-quoted-argument]:=fg=cyan}
 : ${ZSH_HIGHLIGHT_STYLES[back-dollar-quoted-argument]:=fg=cyan}
@@ -670,7 +671,9 @@ _zsh_highlight_highlighter_main_paint()
                  ;|
         '--'*)   style=double-hyphen-option;;
         '-'*)    style=single-hyphen-option;;
-        "'"*)    style=single-quoted-argument;;
+        "'"*)    _zsh_highlight_main_highlighter_highlight_single_quote 1
+                 already_added=1
+                 ;;
         '"'*)    _zsh_highlight_main_highlighter_highlight_double_quote
                  already_added=1
                  ;;
@@ -797,6 +800,25 @@ _zsh_highlight_main_highlighter_check_path()
   return 1
 }
 
+# Highlight single-quoted strings
+_zsh_highlight_main_highlighter_highlight_single_quote()
+{
+  local arg1=$1 i q=\'
+  local -a highlights
+  i=$arg[(ib:arg1+1:)$q]
+
+  if [[ $useroptions[rcquotes] == on ]]; then
+    while [[ $arg[i+1] == "'" ]]; do
+      highlights+=($(( start_pos + i - 1 )) $(( start_pos + ++i )) rc-quote)
+      i=$arg[(ib:i+1:)$q]
+    done
+  fi
+
+  highlights+=($(( start_pos + $1 - 1 )) $(( start_pos + i )) single-quoted-argument $highlights)
+  _zsh_highlight_main_add_region_highlights $highlights
+  REPLY=$i
+}
+
 # Highlight special chars inside double-quoted strings
 _zsh_highlight_main_highlighter_highlight_double_quote()
 {