add less than or equal to

BrianHicks · Jun 10, 2021 · 307e47b · 307e47b
1 parent 7da96d1
commit 307e47b
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Showing 2 changed files with 25 additions and 1 deletion.
diff --git a/src/Datalog.elm b/src/Datalog.elm
@@ -866,6 +866,7 @@ type Token
     | Horn
     | DoubleQuote
     | LessThan
+    | LessThanOrEquals
     | GreaterThan
     | GreaterThanOrEquals
     | Equals
@@ -981,7 +982,9 @@ filterClauseParser =
 opParser : Parser (String -> Term -> Filter)
 opParser =
     Parser.oneOf
-        [ Parser.succeed lt
+        [ Parser.succeed (\lhs rhs -> or (lt lhs rhs) (eq lhs rhs))
+            |. Parser.token lessThanOrEqualsToken
+        , Parser.succeed lt
             |. Parser.token lessThanToken
         , Parser.succeed (\lhs rhs -> or (gt lhs rhs) (eq lhs rhs))
             |. Parser.token greaterThanOrEqualsToken
@@ -1115,6 +1118,11 @@ lessThanToken =
     Parser.Token "<" (ExpectedToken LessThan)
 
 
+lessThanOrEqualsToken : Parser.Token ParsingProblem
+lessThanOrEqualsToken =
+    Parser.Token "<=" (ExpectedToken LessThanOrEquals)
+
+
 greaterThanToken : Parser.Token ParsingProblem
 greaterThanToken =
     Parser.Token ">" (ExpectedToken GreaterThan)

diff --git a/tests/DatalogTests.elm b/tests/DatalogTests.elm
@@ -517,6 +517,22 @@ datalogTests =
                                             (eq "age" (int 18))
                                         )
                                 ]
+                    , test "less than or equal to" <|
+                        \_ ->
+                            expectParses
+                                """
+                                child(name) :-
+                                  person(name, age),
+                                  age <= 17.
+                                """
+                                [ rule "child" [ "name" ]
+                                    |> with "person" [ var "name", var "age" ]
+                                    |> filter
+                                        (or
+                                            (lt "age" (int 17))
+                                            (eq "age" (int 17))
+                                        )
+                                ]
                     ]
                 , todo "rule with negation"
                 ]