[m-rev.] diff: Delete support for highlighting Erlang code in vim syntax file.

[Peter Wang]

vim/syntax/mercury.vim:
    As above.

    Also delete "il" and "IL" as recognised foreign languages.

vim/doc/mercury.txt:
    Update documentation.

diff --git a/vim/doc/mercury.txt b/vim/doc/mercury.txt
index 3f4bf10b0..fac726cc7 100644
--- a/vim/doc/mercury.txt
+++ b/vim/doc/mercury.txt
@@ -136,7 +136,7 @@ if you want to disable this, please use: >
 
     let mercury_no_highlight_tabs = 1
 <
-Highlighting of C, Java, C# and Erlang code is supported by default,
+Highlighting of C, Java and C# code is supported by default,
 disable (if you think loading huge files is slow) with: >
 
     let mercury_no_highlight_foreign = 1
diff --git a/vim/syntax/mercury.vim b/vim/syntax/mercury.vim
index 61e54d7f6..e15d7789a 100644
--- a/vim/syntax/mercury.vim
+++ b/vim/syntax/mercury.vim
@@ -2,7 +2,7 @@
 " Language:     Mercury
 " Maintainer:   Sebastian Godelet <sebastian.godelet at outlook.com>
 " Extensions:   *.m *.moo
-" Last Change:  2018-09-01
+" Last Change:  2020-10-30
 
 " for documentation, please use :help mercury-syntax
 
@@ -308,12 +308,8 @@ if !exists("mercury_no_highlight_foreign") || !mercury_no_highlight_foreign
   syn region  mercuryForeignJavaBlock    matchgroup=mercuryBracket start=/\v\(("Java"|java)/rs=s+1 end=')'
         \ transparent fold contained contains=@mercuryForeign,
         \ mercuryJavaCode,mercuryBlock
-  syn region  mercuryForeignErlangBlock  matchgroup=mercuryBracket start=/\v\(("Erlang"|erlang)/rs=s+1 end=')'
-        \ transparent fold contained contains=@mercuryForeign,
-        \ mercuryErlangCode,mercuryBlock
   syn cluster mercuryForeignBlock contains=mercuryForeignCBlock,
-        \ mercuryForeignCSharpBlock,mercuryForeignJavaBlock,
-        \ mercuryForeignErlangBlock
+        \ mercuryForeignCSharpBlock,mercuryForeignJavaBlock
   syn match   mercuryPragmaForeign /\v^\s*:-\s+pragma\s+foreign_(code|proc|decl|type|export(_enum)?|enum|import_module)/
         \ transparent nextgroup=@mercuryForeignBlock
 
@@ -414,39 +410,11 @@ if !exists("mercury_no_highlight_foreign") || !mercury_no_highlight_foreign
   syn region mercuryJavaCode   matchgroup=mercuryString start=+"+ skip=+""+ end=+"+
         \ transparent fold contained contains=@mercuryCppLike,mercuryCString,mercuryJavaType
 
-    " Declaration for Erlang
-  syn keyword mercuryErlangKeyword contained after and andalso band begin bnot bor bsl bsr bxor case
-        \ catch cond end fun if let not of orelse query receive throw try when xor
-  " syn keyword mercuryErlangBool true false
-  syn match mercuryErlangExtNumLiteral "\v([2-9]|[12][0-9]|3[0-6])#[A-Za-z0-9]+" contained
-  syn match mercuryErlangOperator "\v[?]" contained
-  syn match mercuryErlangLogical "\v[,;.]" contained
-  syn region mercuryErlangString start=+""+ end=+""+ contained contains=@Spell
-  syn region mercuryErlangString start=+\v\\"+ end=+\v\\"+ contained contains=@Spell
-  syn cluster mercuryErlangTerms contains=mercuryErlangBlock,mercuryErlangList,
-        \ mercuryErlangString,mercuryCLikeChar,mercuryCLikeNumber,
-        \ mercuryErlangExtNumLiteral,mercuryFloat,mercuryComment,mercuryKeyword,
-        \ mercuryErlangKeyword, mercuryErlangOperator, mercuryCComment,
-        \ mercuryErlangBool,mercuryOperator,mercurySingleton,mercuryImplication,
-        \ mercuryErlangDCGAction,mercuryErlangLogical, at mercuryFormatting
-  syn region  mercuryErlangList contained matchgroup=mercuryBracket
-        \ start='\[' end=']' transparent fold  contains=@mercuryErlangTerms
-  syn region  mercuryErlangBlock    contained matchgroup=mercuryBracket
-        \ start='(' end=')'  transparent fold  contains=@mercuryErlangTerms
-  syn region  mercuryErlangDCGAction contained matchgroup=mercuryBracket
-        \ start='{' end='}'  transparent fold  contains=@mercuryErlangTerms
-
-  syn cluster mercuryErlang contains=@mercuryErlangTerms,mercuryErlangDCGAction,
-        \ mercuryForeignIface
-
-  syn region mercuryErlangCode   matchgroup=mercuryString start=+"+ skip=+""+ end=+"+
-        \ transparent fold contained contains=@mercuryErlang
-
     " Matching the foreign language name identifiers, this comes after all the
     " code blocks, to match the identifiers in quotes
-  syn match mercuryForeignId /\v<(c|csharp|java|il|erlang)>/ contained
+  syn match mercuryForeignId /\v<(c|csharp|java)>/ contained
   syn region mercuryForeignId contained matchgroup=mercuryString
-        \ start=+\v["](C#|Java|C|I[Ll]|Erlang)["]{-}+rs=s+1 end=+"+
+        \ start=+\v["](C#|Java|C)["]{-}+rs=s+1 end=+"+
 
     " Matching foreign interface builtins and success indicator
   syn keyword mercuryForeignIface contained SUCCESS_INDICATOR
@@ -620,12 +588,6 @@ if !exists("mercury_no_highlight_foreign") || !mercury_no_highlight_foreign
   hi def link mercuryCSharpType       mercuryForeignType
   hi def link mercuryJavaBool         mercuryBool
   hi def link mercuryJavaType         mercuryForeignType
-  hi def link mercuryErlangKeyword    Keyword
-  hi def link mercuryErlangOperator   Operator
-  hi def link mercuryErlangBool       mercuryBool
-  hi def link mercuryErlangExtNumLiteral Number
-  hi def link mercuryErlangString     String
-  hi def link mercuryErlangLogical    mercuryLogical
   if exists("mercury_highlight_extra") && mercury_highlight_extra
     hi def link mercuryForeignType  Type
   else
-- 
2.28.0