feat: Adding ValueEmitter, LambdaEvaluatorSystem

1 files changed, 60 insertions, 0 deletions

diff --git a/core/src/test/java/coffee/liz/lambda/format/ValueEmitterTest.java b/core/src/test/java/coffee/liz/lambda/format/ValueEmitterTest.java
new file mode 100644
index 0000000..c1ab704
--- /dev/null
+++ b/core/src/test/java/coffee/liz/lambda/format/ValueEmitterTest.java
@@ -0,0 +1,60 @@
+package coffee.liz.lambda.format;
+
+import coffee.liz.lambda.LambdaDriver;
+import coffee.liz.lambda.ast.SourceCode;
+import coffee.liz.lambda.eval.Value;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ValueEmitterTest {
+    @Test
+    void emitsFreeInBothSyntaxes() {
+        final Value value = LambdaDriver.interpret(SourceCode.ofArrow("z"));
+
+        final SourceCode arrow = ValueEmitter.emit(value, SourceCode.Syntax.ARROW);
+        final SourceCode lambda = ValueEmitter.emit(value, SourceCode.Syntax.LAMBDA);
+
+        assertEquals("z", assertInstanceOf(SourceCode.Arrow.class, arrow).source());
+        assertEquals("z", assertInstanceOf(SourceCode.Lambda.class, lambda).source());
+    }
+
+    @Test
+    void emitsApplicationInBothSyntaxes() {
+        final Value value = LambdaDriver.interpret(SourceCode.ofArrow("f(x)"));
+
+        final SourceCode arrow = ValueEmitter.emit(value, SourceCode.Syntax.ARROW);
+        final SourceCode lambda = ValueEmitter.emit(value, SourceCode.Syntax.LAMBDA);
+
+        assertEquals("f(x)", assertInstanceOf(SourceCode.Arrow.class, arrow).source());
+        assertEquals("f x", assertInstanceOf(SourceCode.Lambda.class, lambda).source());
+    }
+
+    @Test
+    void emitsClosureWithCaptureMacros() {
+        final Value value = LambdaDriver.interpret(SourceCode.ofArrow("(x -> y -> x)(z)"));
+        final SourceCode emitted = ValueEmitter.emit(value, SourceCode.Syntax.ARROW);
+        final String source = assertInstanceOf(SourceCode.Arrow.class, emitted).source();
+
+        assertTrue(source.contains("let _cap"));
+        assertTrue(source.contains("y -> _cap"));
+
+        // Validate emitted program is parsable and evaluates.
+        final Value roundTrip = LambdaDriver.interpret(emitted);
+        assertInstanceOf(Value.Closure.class, roundTrip);
+    }
+
+    @Test
+    void emitsHygienicCapturesWhenNamesShadow() {
+        final Value value = LambdaDriver.interpret(SourceCode.ofArrow("(x -> y -> x)(y)"));
+        final SourceCode emitted = ValueEmitter.emit(value, SourceCode.Syntax.ARROW);
+        final String source = assertInstanceOf(SourceCode.Arrow.class, emitted).source();
+
+        assertTrue(source.contains("let _cap"));
+        assertTrue(source.contains("y -> _cap"));
+        assertFalse(source.contains("let y ="));
+    }
+}