Update runtime files
diff --git a/runtime/syntax/erlang.vim b/runtime/syntax/erlang.vim
index b8cbf07..0b25619 100644
--- a/runtime/syntax/erlang.vim
+++ b/runtime/syntax/erlang.vim
@@ -2,7 +2,7 @@
" Language: Erlang (http://www.erlang.org)
" Maintainer: Csaba Hoch <csaba.hoch@gmail.com>
" Contributor: Adam Rutkowski <hq@mtod.org>
-" Last Update: 2020-May-26
+" Last Update: 2022-Sep-06
" License: Vim license
" URL: https://github.com/vim-erlang/vim-erlang-runtime
@@ -61,7 +61,8 @@
syn match erlangModifier '\$\%([^\\]\|\\\%(\o\{1,3}\|x\x\x\|x{\x\+}\|\^.\|.\)\)'
" Operators, separators
-syn match erlangOperator '==\|=:=\|/=\|=/=\|<\|=<\|>\|>=\|=>\|:=\|++\|--\|=\|!\|<-\|+\|-\|\*\|\/'
+syn match erlangOperator '==\|=:=\|/=\|=/=\|<\|=<\|>\|>=\|=>\|:=\|?=\|++\|--\|=\|!\|<-\|+\|-\|\*\|\/'
+syn match erlangEqualsBinary '=<<\%(<\)\@!'
syn keyword erlangOperator div rem or xor bor bxor bsl bsr and band not bnot andalso orelse
syn match erlangBracket '{\|}\|\[\|]\||\|||'
syn match erlangPipe '|'
@@ -76,7 +77,8 @@
syn match erlangGlobalFuncRef '\<\%(\a[[:alnum:]_@]*\%(\s\|\n\|%.*\n\)*\.\%(\s\|\n\|%.*\n\)*\)*\a[[:alnum:]_@]*\%(\s\|\n\|%.*\n\)*:\%(\s\|\n\|%.*\n\)*\a[[:alnum:]_@]*\>\%(\%(\s\|\n\|%.*\n\)*/\)\@=' contains=erlangComment,erlangVariable
" Variables, macros, records, maps
-syn match erlangVariable '\<[A-Z_][[:alnum:]_@]*'
+syn match erlangVariable '\<[A-Z][[:alnum:]_@]*'
+syn match erlangAnonymousVariable '\<_[[:alnum:]_@]*'
syn match erlangMacro '??\=[[:alnum:]_@]\+'
syn match erlangMacro '\%(-define(\)\@<=[[:alnum:]_@]\+'
syn region erlangQuotedMacro start=/??\=\s*'/ end=/'/ contains=erlangQuotedAtomModifier
@@ -92,7 +94,7 @@
" Constants and Directives
syn match erlangUnknownAttribute '^\s*-\%(\s\|\n\|%.*\n\)*\l[[:alnum:]_@]*' contains=erlangComment
-syn match erlangAttribute '^\s*-\%(\s\|\n\|%.*\n\)*\%(behaviou\=r\|compile\|export\(_type\)\=\|file\|import\|module\|author\|copyright\|doc\|vsn\|on_load\|optional_callbacks\)\>' contains=erlangComment
+syn match erlangAttribute '^\s*-\%(\s\|\n\|%.*\n\)*\%(behaviou\=r\|compile\|export\(_type\)\=\|file\|import\|module\|author\|copyright\|doc\|vsn\|on_load\|optional_callbacks\|feature\)\>' contains=erlangComment
syn match erlangInclude '^\s*-\%(\s\|\n\|%.*\n\)*\%(include\|include_lib\)\>' contains=erlangComment
syn match erlangRecordDef '^\s*-\%(\s\|\n\|%.*\n\)*record\>' contains=erlangComment
syn match erlangDefine '^\s*-\%(\s\|\n\|%.*\n\)*\%(define\|undef\)\>' contains=erlangComment
@@ -100,8 +102,8 @@
syn match erlangType '^\s*-\%(\s\|\n\|%.*\n\)*\%(spec\|type\|opaque\|callback\)\>' contains=erlangComment
" Keywords
-syn keyword erlangKeyword after begin case catch cond end fun if let of
-syn keyword erlangKeyword receive when try
+syn keyword erlangKeyword after begin case catch cond end fun if let of else
+syn keyword erlangKeyword receive when try maybe
" Build-in-functions (BIFs)
syn keyword erlangBIF abs alive apply atom_to_binary atom_to_list contained
@@ -174,6 +176,7 @@
" Operators, separators
hi def link erlangOperator Operator
+hi def link erlangEqualsBinary ErrorMsg
hi def link erlangRightArrow Operator
if s:old_style
hi def link erlangBracket Normal
@@ -191,6 +194,7 @@
hi def link erlangGlobalFuncCall Function
hi def link erlangGlobalFuncRef Function
hi def link erlangVariable Normal
+hi def link erlangAnonymousVariable erlangVariable
hi def link erlangMacro Normal
hi def link erlangQuotedMacro Normal
hi def link erlangRecord Normal
@@ -203,6 +207,7 @@
hi def link erlangGlobalFuncCall Normal
hi def link erlangGlobalFuncRef Normal
hi def link erlangVariable Identifier
+hi def link erlangAnonymousVariable erlangVariable
hi def link erlangMacro Macro
hi def link erlangQuotedMacro Macro
hi def link erlangRecord Structure