tests/meta.g

   1 // use 'a'-'z' or 'a-z' instead of [a-z]?
   2 // EOF token?
   3 // #include (with renaming?)
   4
   5 s             =  ws! Grammar ws!
   6
   7 Grammar       =  Declaration +/ ws
   8
   9 Declaration   =  NonTerminal
  10               |  ^"#import" ws! FileName (ws! "as" ws! Word)?
  11
  12 FileName      = FileNameChar+ -> [\r\n ]
  13 FileNameChar  = Space:: "\\ "
  14               | ~[\r\n ]
  15
  16 NonTerminal   =  Word           "="     RHS /ws
  17               |  Word  "*" ws! ^"=" ws! RHS
  18               |  Word  "*/" Word ws! ^"=" ws! RHS
  19
  20 RHS           =  (Sequence +/ (ws! "|" ws!)) +/ (ws! ">" ws!)
  21
  22 Elements      =  e*/ws
  23
  24 PreSequence   =  Elements
  25               |  (Quoted|Word)   ^"::" PreSequence /ws
  26               >  PreSequence     ^"/"      e       /ws
  27               |  PreSequence     ^"->"     e       /ws
  28
  29 Sequence      = psx:: PreSequence
  30               |       Sequence ^"&"  Elements /ws
  31               |       Sequence ^"&~" Elements /ws
  32
  33 ec            = ~[\-\]\\]
  34               | escaped
  35
  36 Range         = ec
  37               | ec "-" ec
  38
  39 e             =                (Quoted|Word) ^":" e
  40               >                NonTerminalReference
  41               |                Literal
  42               |                  ^"()"
  43               |                  ^"{" PreSequence "}"    /ws
  44               |                  ^"["  Range* "]"
  45               |                e ^"++"                   /ws -> ~[/]
  46               |                e ^"+"                    /ws -> ~[+]
  47               |                e ^"++/" e                /ws
  48               |                e ^"+/"  e                /ws
  49               |                e ^"**"                   /ws -> ~[/]
  50               |                e ^"*"                    /ws -> ~[*]
  51               |                e ^"**/" e                /ws
  52               |                e ^"*/"  e                /ws
  53               |                     e ^"!"
  54               |                e ^"?"                    /ws
  55               |                  ^"^"   Quoted
  56               >                  ^"(" RHS  ")"           /ws
  57               |                  ^"~" e
  58               |                  ^"\\{"
  59               |                  ^"\\}"
  60
  61 NonTerminalReference = Word
  62 Literal              = Quoted
  63 Word                 = [.a-zA-Z0-9_]++
  64 Quoted               = "\"" ((~[\"\\] | escaped)+) "\""
  65                      | EmptyString
  66                        EmptyString = "\"\""
  67
  68 escaped    = "\n":: "\\n"
  69            | "\r":: "\\r"
  70            |        "\\" ~[nr]
  71
  72 w             = " " | "\n" | "\r"
  73 ws            =  w**
  74               |  w** "//" (~[\n])*! "\n" ws!
  75 wp            =  w++