tests/meta.g

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