instance print VarDecl where
print (VarDecl _ t i e) = maybe ["var"] print t ++ [" ":i:"=":print e] ++ [";"]
+instance toString VarDecl where
+ toString v = concat (print v)
instance toString Type where
toString t = concat $ print t
print FieldTl = print "tl"
print FieldSnd = print "snd"
print FieldFst = print "fst"
+instance toString FieldSelector where
+ toString fs = concat $ print fs
instance print VarDef where
print (VarDef i fs) = printersperse "." [i:printersperse "" fs]
BiLesserEq = "<="; BiGreaterEq = ">="; BiUnEqual = "!=";
BiAnd = "&&"; BiOr = "||"; BiCons = ":"
+instance toString Op1 where
+ toString UnNegation = "!"
+ toString UnMinus = "-"
+
instance print Expr where
print (VarExpr _ vd) = print vd
print (Op2Expr _ e1 o e2) = ["(":print e1] ++
print (FunExpr _ id as fs) = printFunCall id as ++ printSelectors fs
print (EmptyListExpr _) = ["[]"]
print (TupleExpr _ (e1, e2)) = ["(":print e1] ++ [",":print e2] ++ [")"]
+instance toString Expr where
+ toString e = concat $ print e
printSelectors :: [FieldSelector] -> [String]
printSelectors x = case x of [] = [""]; _ = [".":printersperse "." x]
instance zero Pos where
zero = {line=0, col=0}
+
+derive gEq Op1
+instance == Op1 where (==) o1 o2 = gEq{|*|} o1 o2
+instance < Op2 where (<) o1 o2 = toString o1 < toString o2
+instance < Op1 where (<) o1 o2 = toString o1 < toString o2
+
+derive gEq Type
+instance == Type where (==) t1 t2 = gEq{|*|} t1 t2
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