split the Op ctor into binop,prefixop, postfixop and specialop

add support for is null
2013-12-13 21:26:14 +02:00 · 2013-12-13 21:26:14 +02:00 · 4f73f4ec44
commit 4f73f4ec44
parent 955658c41f
4 changed files with 67 additions and 59 deletions
--- a/Language/SQL/SimpleSQL/Syntax.lhs
+++ b/Language/SQL/SimpleSQL/Syntax.lhs
@ -21,7 +21,13 @@
 >                 | Star
 >                 | Star2 String
 >                 | App String [ScalarExpr]
->                 | Op String [ScalarExpr]
+>                   -- the binop, prefixop and postfix op
+>                   -- are used for symbol and keyword operators
+>                 | BinOp String ScalarExpr ScalarExpr
+>                 | PrefixOp String ScalarExpr
+>                 | PostfixOp String ScalarExpr
+>                   -- the special op is used for ternary, mixfix and other non orthodox operators
+>                 | SpecialOp String [ScalarExpr]
 >                 | Case (Maybe ScalarExpr) -- test value
 >                        [(ScalarExpr,ScalarExpr)] -- when branches
 >                        (Maybe ScalarExpr) -- else value