tests/meta.g

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