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module CompilerMacros(compilerMacros) where
import AST
compilerMacros :: Program -> Program
compilerMacros (Program values) = Program (map process values)
process :: Value -> Value
process (VList [VName "define", VName name, VList args, body])
| Just names <- mapM fromVName args = process (VList [VName "define", VName name, VLambda names body])
| otherwise = error "Invalid 'define' shorthand syntax: Invalid argument list"
process (VList [VName "define", VName name, value]) = VDefine name (process value)
process (VList (VName "define" : _)) = error "Invalid 'define' syntax"
process (VList [VName "lambda", VList args, body])
| Just names <- mapM fromVName args = process (VLambda names body)
| otherwise = error "Invalid 'lambda' syntax: Invalid argument list"
process (VList (VName "lambda" : _)) = error "Invalid 'lambda' syntax"
process (VList [VName "lambdarec", VName recname, VList args, body])
| Just names <- mapM fromVName args = process (VLambdaRec recname names body)
| otherwise = error "Invalid 'lambdarec' syntax: Invalid argument list"
process (VList (VName "lambdarec" : _)) = error "Invalid 'lambdarec' syntax"
-- process (VList [VName "let", VList args, body]) =
-- case sequence [case p of { [n, v] -> Just (n, v); _ -> Nothing } | VList p <- args] of
-- Just pairs ->
-- process (VList (VList [VName "lambda", VList (map fst pairs), body] : map snd pairs))
-- Nothing ->
-- error "Invalid 'let' syntax: Invalid variable list (not all pairs)"
process (VList [VName "let", VList args, body]) =
case sequence [case p of { [VName n, v] -> Just (n, v); _ -> Nothing } | VList p <- args] of
Just pairs ->
process (VLet pairs body)
Nothing ->
error "Invalid 'let' syntax: Invalid variable list (not all pairs)"
process (VList (VName "let" : _)) = error "Invalid 'let' syntax: Invalid argument list"
process (VList values) = VList (map process values)
process (VDefine name body) = VDefine name (process body)
process (VLambda args body) = VLambda args (process body)
process (VLambdaRec recname args body) = VLambdaRec recname args (process body)
process (VLet args body) = VLet [(name, process value) | (name, value) <- args] (process body)
process v@(VNum _) = v
process v@(VString _) = v
process v@(VName _) = v
process v@(VQuoted _) = v
process v@(VBuiltin _) = v
process v@VEllipsis = v
|
