tests/meta.g

   1 s             =  !ws Grammar ws              => "gram"
   2 Grammar       =  NonTerminal +/ ws           => "grammar"
   3 NonTerminal   =  word  !wp ^"=" !wp RHS
   4
   5 RHS           =  (Conjuncts +/ (!ws "|" !ws)) +/ (!ws ">" !ws)
   6
   7 Conjuncts     =  Sequence
   8               |  Sequence ^"&"  Elements  /ws
   9               |  Sequence ^"&~" Elements  /ws
  10 Elements      =  e*/ws
  11
  12 PreSequence   = Elements => "ps"
  13               | PreSequence !wp ^"/"  !ws e
  14               | PreSequence     ^"->"     e /ws
  15 //              | (Quoted|word)   ^"::" PreSequence /ws
  16               | PreSequence     ^"=>" ("[]"|"()"|word|Quoted) /ws
  17 Sequence      = PreSequence    => "psx"
  18
  19 ec            = ~[\-\]\\]
  20               | escaped
  21
  22 Range         = ec          => "range"
  23               | ec ^"-" ec
  24
  25 e             =
  26                 (Quoted|word) ^":" e
  27               >  word                          => "nonTerminal"
  28               |  Quoted                        => "literal"
  29               |    ^"()"
  30               |    ^"{" Sequence "}"       /ws
  31               |    ^"["  Range* "]"
  32               |  e ^"++"                   /ws -> ~[/]
  33               |  e ^"+"                    /ws -> ~[+]
  34               |  e ^"++/" e                /ws
  35               |  e ^"+/"  e                /ws
  36               |  e ^"**"                   /ws -> ~[/]
  37               |  e ^"*"                    /ws -> ~[*]
  38               |  e ^"**/" e                /ws
  39               |  e ^"*/"  e                /ws
  40               |    ^"!"   e                /ws
  41               |  e ^"?"                    /ws
  42               |    ^"^" Quoted             /ws
  43
  44               |     "(" word         ^")"  /ws
  45               >    ^"(" RHS  ")"           /ws
  46               |    ^"~" e
  47
  48 word       = [a-zA-Z0-9_]++
  49 Quoted     = "\"" ((~[\"\\] | escaped)+) "\""
  50            | "\"\"" => ""
  51 escaped    = "\\n" => "\n"
  52            | "\\r" => "\r"
  53            | "\\" ~[nr]
  54
  55
  56 w             = " " | "\n" | "\r"
  57 ws            =  w** => ()
  58               |  w** "//" ~[\n]* "\n" ws => ()
  59 wp            =  w++