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Diffstat (limited to 'docs/examples/parsing/lambda/TestParser.scala')
-rw-r--r-- | docs/examples/parsing/lambda/TestParser.scala | 68 |
1 files changed, 0 insertions, 68 deletions
diff --git a/docs/examples/parsing/lambda/TestParser.scala b/docs/examples/parsing/lambda/TestParser.scala deleted file mode 100644 index d26589da1b..0000000000 --- a/docs/examples/parsing/lambda/TestParser.scala +++ /dev/null @@ -1,68 +0,0 @@ -package examples.parsing.lambda - -import scala.util.parsing.input.Reader -import scala.util.parsing.combinator.lexical.StdLexical -import scala.util.parsing.combinator.syntactical.StdTokenParsers -import scala.util.parsing.combinator.ImplicitConversions - -/** - * Parser for an untyped lambda calculus - * - * @author Miles Sabin (adapted slightly by Adriaan Moors) - */ -trait TestParser extends StdTokenParsers with ImplicitConversions with TestSyntax -{ - type Tokens = StdLexical - val lexical = new StdLexical - lexical.reserved ++= List("unit", "let", "in", "if", "then", "else") - lexical.delimiters ++= List("=>", "->", "==", "(", ")", "=", "\\", "+", "-", "*", "/") - - - def name : Parser[Name] = ident ^^ Name - - // meaning of the arguments to the closure during subsequent iterations - // (...(expr2 op1 expr1) ... op1 expr1) - // ^a^^^ ^o^ ^b^^^ - // ^^^^^^^a^^^^^^^ ^o^ ^^b^^ - def expr1 : Parser[Term] = - chainl1(expr2, expr1, op1 ^^ {o => (a: Term, b: Term) => App(App(o, a), b)}) - - def expr2 : Parser[Term] = - chainl1(expr3, expr2, op2 ^^ {o => (a: Term, b: Term) => App(App(o, a), b)}) - - def expr3 : Parser[Term] = - chainl1(expr4, expr3, op3 ^^ {o => (a: Term, b: Term) => App(App(o, a), b)}) - - def expr4 : Parser[Term] = - ( "\\" ~> lambdas - | ("let" ~> name) ~ ("=" ~> expr1) ~ ("in" ~> expr1) ^^ flatten3(Let) - | ("if" ~> expr1) ~ ("then" ~> expr1) ~ ("else" ~> expr1) ^^ flatten3(If) - | chainl1(aexpr, success(App(_: Term, _: Term))) - ) - - def lambdas : Parser[Term] = - name ~ ("->" ~> expr1 | lambdas) ^^ flatten2(Lam) - - def aexpr : Parser[Term] = - ( numericLit ^^ (_.toInt) ^^ Lit - | name ^^ Ref - | "unit" ^^^ Unit() - | "(" ~> expr1 <~ ")" - ) - - def op1 : Parser[Term] = - "==" ^^^ Ref(Name("==")) - - def op2 : Parser[Term] = - ( "+" ^^^ Ref(Name("+")) - | "-" ^^^ Ref(Name("-")) - ) - - def op3 : Parser[Term] = - ( "*" ^^^ Ref(Name("*")) - | "/" ^^^ Ref(Name("/")) - ) - - def parse(r: Reader[char]) : ParseResult[Term] = - phrase(expr1)(new lexical.Scanner(r)) -} |