Escape identifiers that match keywords

Author: natefaubion

src/SqlSquared/Parser/Tokenizer.purs

@@ -1,5 +1,6 @@
 module SqlSquared.Parser.Tokenizer
   ( tokenize
+  , keywords
   , Token(..)
   , Literal(..)
   , PositionedToken

src/SqlSquared/Signature/Ident.purs

@@ -1,6 +1,19 @@
 module SqlSquared.Signature.Ident where
 
-import SqlSquared.Utils (escapeIdent)
+import Prelude
+
+import Data.Set as Set
+import Data.String as S
+import Data.String.Regex (test, replace) as Regex
+import Data.String.Regex.Flags (ignoreCase, global) as Regex
+import Data.String.Regex.Unsafe (unsafeRegex) as Regex
+import SqlSquared.Parser.Tokenizer (keywords)
 
 printIdent ∷ String → String
-printIdent = escapeIdent "`"
+printIdent ident =
+  if Regex.test identifier ident && not (Set.member (S.toLower ident) keywords)
+    then ident
+    else "`" <> Regex.replace tick ("\\`") ident <> "`"
+  where
+  identifier = Regex.unsafeRegex "^[a-z][_a-z0-9]*$" Regex.ignoreCase
+  tick = Regex.unsafeRegex "`" Regex.global

src/SqlSquared/Utils.purs

@@ -2,9 +2,6 @@ module SqlSquared.Utils where
 
 import Prelude
 import Data.Functor.Coproduct (Coproduct, coproduct)
-import Data.String.Regex (test, replace) as Regex
-import Data.String.Regex.Flags (ignoreCase, global) as Regex
-import Data.String.Regex.Unsafe (unsafeRegex) as Regex
 import Data.Tuple (Tuple(..))
 
 infixr 4 type Tuple as ×
@@ -17,12 +14,3 @@ composeFlipped ∷ ∀ a b c d. Semigroupoid a ⇒ a b c → a c d → a b d
 composeFlipped f g = compose g f
 
 infixr 9 composeFlipped as ⋙
-
-escapeIdent ∷ String → String → String
-escapeIdent delim ident =
-  if Regex.test identifier ident
-    then ident
-    else delim <> Regex.replace tick ("\\" <> delim) ident <> delim
-  where
-  identifier = Regex.unsafeRegex "^[a-z][_a-z0-9]*$" Regex.ignoreCase
-  tick = Regex.unsafeRegex delim Regex.global

test/src/Parse.purs

@@ -176,6 +176,14 @@ testSuite1 = do
     industry
   """
 
+  parseFail """
+    select foo as between from bar
+  """
+
+  parseSucc """
+    select foo as `between` from bar
+  """
+
 testSuite2 ∷ ∀ e. TestSuite (testOutput ∷ Console.TESTOUTPUT | e)
 testSuite2 = do
   parseSucc """