ast.icl

   1 implementation module ast
   2
   3 import StdList
   4 import StdOverloaded
   5 import Data.Func
   6 import Text.PPrint
   7
   8 instance toString AST where toString a = display $ renderCompact $ pretty a
   9 instance toString Function where toString a = display $ renderCompact $ pretty a
  10 instance toString Expression where toString a = display $ renderCompact $ pretty a
  11 instance toString Value where toString a = display $ renderCompact $ pretty a
  12
  13 instance Pretty Expression
  14 where
  15         pretty (Literal v) = pretty v
  16         pretty (Variable v) = string v
  17         pretty (Apply a b) = parens (pretty a <+> pretty b)
  18         pretty (Lambda a b) = string "\\" <-> string a <+> string "->" <+> pretty b
  19         pretty (Let v a b) = string "let" <+> string v <+> string "=" <+> pretty a <+> string "in" <+> pretty b
  20         pretty (Code b) = string "code" <+> string b
  21
  22 instance Pretty Function
  23 where
  24         pretty (Function n args a) = string n <+> fold (<+>) (map string args) <+> string "=" <+> pretty a
  25
  26 instance Pretty AST
  27 where
  28         pretty (AST a) = pretty a
  29
  30 instance Pretty Value
  31 where
  32         pretty (Int i) = int i
  33         pretty (Bool b) = bool b
  34         pretty (Char c) = char c