Merge pull request #2 from LunarClient/add-conditionals

Added Conditionals and related tests
LunarClient · Nov 2, 2023 · bcb0d5d · bcb0d5d
2 parents 348a6fa + 16b5189
commit bcb0d5d
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Showing 6 changed files with 61 additions and 3 deletions.
diff --git a/src/main/java/com/eliotlash/molang/Parser.java b/src/main/java/com/eliotlash/molang/Parser.java
@@ -300,9 +300,12 @@ private Expr unary() {
         Expr access = access();
         if (match(QUESTION)) {
             Expr left = expression();
-            consume(COLON, "Expected ':' after ternary");
-            Expr right = expression();
-            return new Expr.Ternary(access, left, right);
+            if (match(COLON)) {
+                Expr right = expression();
+                return new Expr.Ternary(access, left, right);
+            } else {
+                return new Expr.Conditional(access, left);
+            }
         }
         if (match(ARROW)) {
             Expr right = expression();

diff --git a/src/main/java/com/eliotlash/molang/ast/ASTTransformation.java b/src/main/java/com/eliotlash/molang/ast/ASTTransformation.java
@@ -83,6 +83,11 @@ public Expr visitNot(Expr.Not expr) {
 		return new Expr.Not(visit(expr.value()));
 	}
 
+	@Override
+	public Expr visitConditional(Expr.Conditional expr) {
+		return new Expr.Conditional(visit(expr.condition()), visit(expr.ifTrue()));
+	}
+
 	@Override
 	public Expr visitTernary(Expr.Ternary expr) {
 		return new Expr.Ternary(visit(expr.condition()), visit(expr.ifTrue()), visit(expr.ifFalse()));

diff --git a/src/main/java/com/eliotlash/molang/ast/Evaluator.java b/src/main/java/com/eliotlash/molang/ast/Evaluator.java
@@ -187,6 +187,13 @@ public Double visitNot(Expr.Not expr) {
         return evaluate(expr.value()) == 0 ? 1.0 : 0.0;
     }
 
+    @Override
+    public Double visitConditional(Expr.Conditional expr) {
+        double result = evaluate(expr.condition());
+        if (result == 0) return 0.0;
+        return evaluate(expr.ifTrue());
+    }
+
     @Override
     public Double visitTernary(Expr.Ternary expr) {
         Expr branch = evaluate(expr.condition()) == 0 ? expr.ifFalse() : expr.ifTrue();

diff --git a/src/main/java/com/eliotlash/molang/ast/Expr.java b/src/main/java/com/eliotlash/molang/ast/Expr.java
@@ -157,6 +157,16 @@ public <R> R accept(Visitor<R> visitor) {
         }
     }
 
+    /**
+     * condition ? ifTrue
+     */
+    record Conditional(Expr condition, Expr ifTrue) implements Expr {
+        @Override
+        public <R> R accept(Visitor<R> visitor) {
+            return visitor.visitConditional(this);
+        }
+    }
+
     /**
      * condition ? ifTrue : ifFalse
      */
@@ -228,6 +238,8 @@ default R visit(Expr node) {
 
         R visitNot(Not expr);
 
+        R visitConditional(Conditional expr);
+
         R visitTernary(Ternary expr);
 
         R visitSwitchContext(SwitchContext expr);

diff --git a/src/test/java/com/eliotlash/molang/ParserTest.java b/src/test/java/com/eliotlash/molang/ParserTest.java
@@ -46,6 +46,31 @@ void testOperators() {
 		}
 	}
 
+	@Test
+	void testConditionals() {
+		// Binary Conditional
+		assertEquals(new Expr.Conditional(c(0), c(20)), e("0 ? 20"));
+		assertEquals(
+				new Expr.Conditional(c(0), paren(new Expr.Conditional(c(20), c(30)))),
+				e("0 ? (20 ? 30)")
+		);
+		// Ternary Conditional
+		assertEquals(new Expr.Ternary(c(0), c(10), c(20)), e("0 ? 10 : 20"));
+		assertEquals(
+				new Expr.Ternary(c(0), paren(new Expr.Ternary(c(10), c(20), c(30))), c(20)),
+				e("0 ? (10 ? 20 : 30) : 20")
+		);
+		// Combinations
+		assertEquals(
+				new Expr.Conditional(c(0), new Expr.Ternary(c(10), c(20), c(30))),
+				e("0 ? 10 ? 20 : 30")
+		);
+		assertEquals(
+				new Expr.Ternary(c(0), c(10), new Expr.Conditional(c(20), c(30))),
+				e("0 ? 10 : 20 ? 30")
+		);
+	}
+
 	@Test
 	void testMath() {
 		Expr.Constant twenty = c(20);

diff --git a/src/test/java/com/eliotlash/molang/ast/EvaluatorTest.java b/src/test/java/com/eliotlash/molang/ast/EvaluatorTest.java
@@ -87,6 +87,12 @@ void visitNot() {
 		assertEquals(1, eval.visitNot(new Expr.Not(c(0))));
 	}
 
+	@Test
+	void visitConditional() {
+		assertEquals(10, eval.visitConditional(new Expr.Conditional(c(1), c(10))));
+		assertEquals(0, eval.visitConditional(new Expr.Conditional(c(0), c(10))));
+	}
+
 	@Test
 	void visitTernary() {
 		assertEquals(10, eval.visitTernary(new Expr.Ternary(c(1), c(10), c(30))));