; [meta.sty] Meta-grammar for composed, indendet files

Language meta


Regular Grammar

; Character Set

  let Byte        = '\00' .. '\ff' ; all extended ascii
  let Control     = '\00' .. '\1f' ; control
                  |          '\7f' ; DEL
                  |          '\ff' ; space-like extended ascii

; Basic elements of tokens

  let Printable   = Byte - Control

  ign Space       = " "            ; ASCII - Space
  ign Line        = "\n" | "\r\n"  ; UNIX / CPM / DOS
                  | "\r"           ; Mac
  ign Page        = "\p"           ; weak separation convention

  ign Etx         = "\1a" {Byte}   ; CPM / older DOS Versions

  let Digit       = '0' .. '9'
  let Letter      = 'a' .. 'z' | 'A' .. 'Z'

; final tokens

  tok Ide         = ( Letter | '_' ) { Digit | Letter | '_.' }
  tok Opr         = ':()'

; comments

  com Comment     = ';' {Printable}


Context Free Grammar

  start Source
  :dfn : Parts

  let Parts
  :nil :
  :cons: Elm Parts

  let Typ
  :nul :
  :dfn : ":" Ide

  let Elm
  :txt : "text" 
  :grp : Ide Typ XParts 

  let XParts
  :nil :
  :ign0: "(" Parts ")"