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(* Uses the generated lexer and parser to export parsing functions
*)
signature PARSE =
sig
structure Absyn : ABSYN
(* parse a program from a string *)
val prog_parse : string -> Absyn.absyn
(* parse a query from a string *)
val query_parse : string -> Absyn.absyn
(* parse a program in a file *)
val file_parse : string -> Absyn.absyn
(* parse a query from the standard input *)
val top_parse : unit -> Absyn.absyn
end (* signature PARSE *)
functor Parse (structure Absyn : ABSYN
structure Interface : INTERFACE
structure Parser : PARSER
sharing type Parser.arg = Interface.arg
sharing type Parser.pos = Interface.pos
sharing type Parser.result = Absyn.absyn
structure Tokens : Fol_TOKENS
sharing type Tokens.token = Parser.Token.token
sharing type Tokens.svalue = Parser.svalue
) : PARSE =
struct
structure Absyn = Absyn
fun parse (dummyToken,lookahead,reader : int -> string) =
let val _ = Interface.init_line()
val empty = !Interface.line
val dummyEOF = Tokens.EOF(empty,empty)
val dummyTOKEN = dummyToken(empty,empty)
fun invoke lexer =
let val newLexer = Parser.Stream.cons(dummyTOKEN,lexer)
in Parser.parse(lookahead,newLexer,Interface.error,
Interface.nothing)
end
fun loop lexer =
let val (result,lexer) = invoke lexer
val (nextToken,lexer) = Parser.Stream.get lexer
in if Parser.sameToken(nextToken,dummyEOF) then result
else loop lexer
end
in loop (Parser.makeLexer reader)
end
fun string_reader s =
let val next = ref s
in fn _ => !next before next := ""
end
fun prog_parse s = parse (Tokens.PARSEPROG,15,string_reader s)
fun query_parse s = parse (Tokens.PARSEQUERY,15,string_reader s)
fun file_parse name =
let val dev = TextIO.openIn name
in (parse (Tokens.PARSEPROG,15,fn i => TextIO.inputN(dev,i)))
before TextIO.closeIn dev
end
fun top_parse () =
parse (Tokens.PARSEQUERY,0,(fn i => TextIO.inputLine TextIO.stdIn))
end (* functor Parse *)
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