[m-rev.] for review: Aligning the Vim syntax file to match the Mercury language more closely

[Sebastian Godelet]

Fixed escaping of the escape character in strings,
added more details to the Vim README and
moved file type detection to vim/ftdetect,
such that one can use
    $ cp -r vim/ ~/.vim
to copy the Vim syntax files without conflicts.

vim/README:
    Removed warning about ~/.vim/after/filetype.vim,
    add utf-8 encoding detection.
vim/after/filetype.vim:
    moved to vim/ftdetect/mercury.vim.
vim/syntax/mercury.vim:
    see above.

diff --git a/vim/README b/vim/README
index fc24187..30e0650 100644
--- a/vim/README
+++ b/vim/README
@@ -1,4 +1,4 @@
-Mercury Syntax Highlighting Under Vim 6.0
+Mercury Syntax Highlighting Under Vim 6.0+

 1. Create a diretory `~/.vim':

@@ -8,24 +8,31 @@ Mercury Syntax Highlighting Under Vim 6.0

  $ cp -r . ~/.vim

-IMPORTANT: If you already have a file `~/.vim/after/filetype.vim' then you
-should copy the files from this directory one by one, except for
-`after/filetype.vim' which you should append to your own
-`~/.vim/after/filetype.vim'.
-
 3. Ensure you have the following lines in your `~/.vimrc' file:

  filetype on
  filetype plugin on
  syntax enable
+ set modeline
+
+4. It is advisable to have the following file encoding detection lines
+in your ~/.vimrc:

-4. If you wish to change the colour scheme used by Vim's syntax highlighting,
+ if has("multi_byte")
+   set encoding=utf-8
+   setglobal fileencoding=utf-8
+   if &termencoding == ""
+     let &termencoding = &encoding
+   endif
+ endif
+
+5. If you wish to change the colour scheme used by Vim's syntax highlighting,
 we suggest you put the necessary commands in `~/.vim/colors/mycolours.vim'
 and append the following to the above list of commands in your `~/.vimrc':

  colors mycolours

-4. Vim will load `~/.vim/syntax/mercury.vim' and `~/.vim/ftplugin/mercury.vim'
+6. Vim will load `~/.vim/syntax/mercury.vim' and `~/.vim/ftplugin/mercury.vim'
 automatically when opening a .m or .moo file.

 The syntax file describes two options you may wish to alter from your
@@ -33,3 +40,6 @@ The syntax file describes two options you may wish
to alter from your

 The ftplugin file defines a number of useful keyboard mappings you may wish to
 consider.
+
+If you want to add a custom extension for Mercury source files, then modify the
+ftdetect/mercury.vim file. Currently .m and .moo are recognised.
diff --git a/vim/after/filetype.vim b/vim/after/filetype.vim
deleted file mode 100644
index 97f9076..0000000
--- a/vim/after/filetype.vim
+++ /dev/null
@@ -1,6 +0,0 @@
-" filetype.vim
-" vim: ts=2 sw=2 et
-
-augroup filetypedetect
-  au! BufRead,BufNewFile  *.m,*.moo         setfiletype mercury
-augroup END
diff --git a/vim/ftdetect/mercury.vim b/vim/ftdetect/mercury.vim
new file mode 100644
index 0000000..b535dcf
--- /dev/null
+++ b/vim/ftdetect/mercury.vim
@@ -0,0 +1,4 @@
+" mercury.vim
+" vim: ts=2 sw=2 et
+
+au! BufRead,BufNewFile  *.m,*.moo         setfiletype mercury
diff --git a/vim/syntax/mercury.vim b/vim/syntax/mercury.vim
index 9d37f94..03ddf7a 100644
--- a/vim/syntax/mercury.vim
+++ b/vim/syntax/mercury.vim
@@ -78,7 +78,7 @@ syn match   mercuryImplication  +<=>\|<=\|=>\|/\\\|\\/+
 syn match   mercuryNumCode      +0'.\|0[box][0-9a-fA-F]*+
 syn region  mercuryAtom         start=+'+ skip=+\\.+ end=+'+
 syn region  mercuryString       start=+"+ skip=+\\.+ end=+"+
                    contains=mercuryStringFmt
-syn match   mercuryStringFmt
+\\[abfnrtv]\|\\x[0-9a-fA-F]*\\\|%[-+# *.0-9]*[dioxXucsfeEgGp]+

contained
+syn match   mercuryStringFmt
/\\[abfnrtv\\"]\|\\x[0-9a-fA-F]\+\\\|%[-+# *.0-9]*[dioxXucsfeEgGp]/
 contained
 syn region  mercuryClauseHead   start=+^[a-zA-Z]+
end=+=\|:-\|\.\s*$\|-->+
contains=mercuryComment,mercuryCComment,mercuryAtom,mercuryString
 syn region  mercuryCComment     start=+/\*+ end=+\*/+
                        contains=mercuryToDo
 if !exists("mercury_no_highlight_overlong") || !mercury_no_highlight_overlong