VimL - expressions (PEG)

; VimL (Vim Script) Parser
; Barry Arthur, 29 Oct 2011

.skip_white = true
.namespace = 'viml_parser'
.parser_name = 'viml#parser'
.root_element = 'viml'

<expr1>           ::=  <expr2> '?' <expr1> ':' <expr1>
<expr2>           ::=  <expr3> '||' <expr3>
<expr3>           ::=  <expr4> '&&' <expr4>
<expr4>           ::=  (<expr5> <eqop> <expr5>) / (<expr5> <isop> <expr5>)
<expr5>           ::=  <expr5> <addop> <expr6>
<expr6>           ::=  <expr7> <mulop> <expr7>
<expr7>           ::=  <unop> <expr8>
<expr8>           ::=  (<expr9> '[' (<exprange> / <expr1>) ']') / (<expr9> '.' <ident>) / (<expr9> '(' <exprlist> ')' / <expr7>
<expr9>           ::=  <number> / <string> / <list> / <dict> / <optval> / <nestedexpr> / <envvar> / <regval> / <funccall> / <bracedfunccall> / <ident> / <bracedident>

<eqop>            ::=  ('==' / '!=' / '>=' / '>' / '<=' / '<' / '=~' / '!~') ('?' / '#')?
<isop>            ::=  'is' 'not'?
<addop>           ::=  '+' / '-' / '.'
<mulop>           ::=  '*' / '/' / '%'
<unop>            ::=  '!' / '-' / '+'
<exprange>        ::=  <expr1> ':' <expr1>

<number>          ::=  '[-+]\?\d*\.\?\d\+\%([eE][-+]\?\d\+\)\?'
<sqstr>           ::=  "'" "'"! '.'* "'"
<dqstr>           ::=  '"' '"'! '.'* '"'
<string>          ::=  <sqstr> / <dqstr>
<list>            ::=  '[' <exprlist> ']'
<exprlist>        ::=  (<expr1> (',' <expr1>)*)?
<dict>            ::=  '{' (<dictpair> (',' <dictpair>)*)? '}'
<dictpair>        ::=  <expr1> ':' <expr1>

<optval>          ::=  '&' <ident>

<nestedexpr>      ::=  '(' <expr1> ')'

<ident>           ::=  '\h\w*'
<bracedident>     ::=  '\h\w*{\w*}\w*'
<envvar>          ::=  '$[A-Z]\+'
<regval>          ::=  '@[a-z0-9_/.+*"'']'

<funccall>        ::=  <ident> '(' <exprlist> ')'
<bracedfunccall>  ::=  <bracedident> '(' <exprlist> ')'