$namespace=SyntaxAnalyzer

COMPILER GPDefSyntaxAnalyzer

CHARACTERS
  letter = 'A'..'Z' + 'a'..'z'.
  digit = '0'..'9'.

TOKENS
  ident = letter {letter | digit} .

COMMENTS
  FROM "/*" TO "*/" NESTED

IGNORE '\t' + '\r' + '\n'

PRODUCTIONS
  GPDefSyntaxAnalyzer = 
    "PROBLEM" ident 
    ["CODE" "<<" {ANY} ">>" ]
    ["INIT" "<<" {ANY} ">>" ]
    "NONTERMINALS" { NonterminalDecl }
    "TERMINALS" { TerminalDecl }
    "RULES" { RuleDef } 
    ("MAXIMIZE" | "MINIMIZE") "<<" {ANY} ">>" 
    "END" ident '.'.


  SemDecl = "LOCAL" "<<" {ANY} ">>" 
  .

  SemAction = "SEM" "<<" {ANY} ">>" 
  .

  NonterminalDecl = ident "<<" {ANY} ">>"  '.'
  .

  TerminalDecl = ident "<<" {ANY} ">>" 
    [ "CONSTRAINTS" ConstraintDef ]
    '.'
  .

  ConstraintDef = { ConstraintRule }.
  ConstraintRule = ident "IN" SetDefinition .
  SetDefinition = 
    "SET" "<<" {ANY} ">>" 
    | "RANGE" "<<" {ANY} ">>" ".." "<<" {ANY} ">>" 
  .

  RuleDef = ident "<<" {ANY} ">>"  '=' [SemDecl] SynExpr '.'
  .

  SynExpr = SynTerm { '|' SynTerm }
  .

  SynTerm = SynFact { SynFact }
  .

  SynFact = 
    ident "<<" {ANY} ">>" 
    | "EPS"
    | '(' SynExpr ')'
    | '[' SynExpr ']'
    | '{' SynExpr '}'
    | SemAction
  .

END GPDefSyntaxAnalyzer.