Compile expressions to stack IR

1 files changed, 71 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/stackir/StackCompilerFunctionExpressionTests.java b/src/test/java/org/shedlang/compiler/stackir/StackCompilerFunctionExpressionTests.java
new file mode 100644
index 00000000..b0ab21cc
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/stackir/StackCompilerFunctionExpressionTests.java
@@ -0,0 +1,71 @@
+package org.shedlang.compiler.stackir;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.ast.typed.Typed;
+import org.shedlang.compiler.ast.typed.TypedFunctionExpressionNode;
+import org.shedlang.compiler.stackir.instructions.DefineFunctionInstruction;
+import org.shedlang.compiler.types.Types;
+
+import static org.shedlang.compiler.stackir.instructions.InstructionMatchers.*;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.*;
+
+public class StackCompilerFunctionExpressionTests {
+    @Test
+    public void functionIsCompiledToDefineFunctionInstruction() {
+        var node = TypedFunctionExpressionNode.builder()
+            .addPositionalParam("x", Typed.typeLevelReference("String", Types.STRING))
+            .addNamedParam("y", Typed.typeLevelReference("Int", Types.INT))
+            .addFreeVariable("z")
+            .addStatement(Typed.expressionStatement(Typed.stringLiteral("hello")))
+            .build();
+        var context = StackCompiler.Context.EMPTY
+            .addShedVariable("f")
+            .addShedVariable("z");
+
+        var result = StackCompiler.compileExpression(node, context);
+
+        assertThat(result.instructions(), isSequence(
+            instanceOf(
+                DefineFunctionInstruction.class,
+                has("name", x -> x.name(), equalTo("anonymous")),
+                has("positionalParams", x -> x.positionalParams(), isSequence(
+                    isDefineFunctionInstructionParam("x__0")
+                )),
+                has("namedParams", x -> x.namedParams(), isSequence(
+                    isDefineFunctionInstructionParam("y__0")
+                )),
+                has("freeVariables", x -> x.freeVariables(), containsExactly(
+                    has("name", x -> x.name(), equalTo("z__0"))
+                )),
+                has("body", x -> x.body(), isSequence(
+                    isPushStringInstruction("hello"),
+                    isDiscardInstruction(),
+                    isPushUnitInstruction(),
+                    isReturnInstruction()
+                ))
+            )
+        ));
+    }
+
+    @Test
+    public void whenLastStatementIsBlockReturnThenThatValueIsReturned() {
+        var node = TypedFunctionExpressionNode.builder()
+            .addStatement(Typed.blockReturn(Typed.stringLiteral("hello")))
+            .build();
+        var context = StackCompiler.Context.EMPTY
+            .addShedVariable("f");
+
+        var result = StackCompiler.compileExpression(node, context);
+
+        assertThat(result.instructions(), isSequence(
+            instanceOf(
+                DefineFunctionInstruction.class,
+                has("body", x -> x.body(), isSequence(
+                    isPushStringInstruction("hello"),
+                    isReturnInstruction()
+                ))
+            )
+        ));
+    }
+}