Compile string addition into string-add instruction

5 files changed, 55 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/typed/Typed.java b/src/test/java/org/shedlang/compiler/ast/typed/Typed.java
index 09af73cc..f7dfb097 100644
--- a/src/test/java/org/shedlang/compiler/ast/typed/Typed.java
+++ b/src/test/java/org/shedlang/compiler/ast/typed/Typed.java
@@ -126,6 +126,18 @@ public class Typed {
         return new TypedReturnNode(expression, Sources.NULL);
     }
 
+    public static TypedBinaryOperationNode stringAdd(
+        TypedExpressionNode left,
+        TypedExpressionNode right
+    ) {
+        return new TypedBinaryOperationNode(
+            TypedBinaryOperator.STRING_ADD,
+            left,
+            right,
+            Sources.NULL
+        );
+    }
+
     public static TypedTargetNode targetVariable(String name) {
         return new TypedTargetNode.Variable(name, Sources.NULL);
     }
diff --git a/src/test/java/org/shedlang/compiler/stackir/InstructionSerializerTests.java b/src/test/java/org/shedlang/compiler/stackir/InstructionSerializerTests.java
index c6046847..3ce690b2 100644
--- a/src/test/java/org/shedlang/compiler/stackir/InstructionSerializerTests.java
+++ b/src/test/java/org/shedlang/compiler/stackir/InstructionSerializerTests.java
@@ -206,6 +206,15 @@ public class InstructionSerializerTests {
         assertThat(string, equalTo("(return)"));
     }
 
+    @Test
+    public void canSerializeStringAdd() {
+        var instruction = Instructions.stringAdd();
+
+        var string = serialize(instruction);
+
+        assertThat(string, equalTo("(string-add)"));
+    }
+
     private String serialize(Instruction instruction) {
         var builder = new StringBuilder();
         InstructionSerializer.serialize(instruction, builder);
diff --git a/src/test/java/org/shedlang/compiler/stackir/StackCompilerStringAddTests.java b/src/test/java/org/shedlang/compiler/stackir/StackCompilerStringAddTests.java
new file mode 100644
index 00000000..29bf576d
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/stackir/StackCompilerStringAddTests.java
@@ -0,0 +1,26 @@
+package org.shedlang.compiler.stackir;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.ast.typed.Typed;
+
+import static org.shedlang.compiler.stackir.instructions.InstructionMatchers.*;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.isSequence;
+
+public class StackCompilerStringAddTests {
+    @Test
+    public void stringAddIsCompiledToStringAddInstruction() {
+        var node = Typed.stringAdd(
+            Typed.stringLiteral("a"),
+            Typed.stringLiteral("b")
+        );
+
+        var instructions = StackCompiler.compileExpression(node);
+
+        assertThat(instructions, isSequence(
+            isPushStringInstruction("a"),
+            isPushStringInstruction("b"),
+            isStringAddInstruction()
+        ));
+    }
+}
diff --git a/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java b/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java
index a47e7c75..8b2661f7 100644
--- a/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java
+++ b/src/test/java/org/shedlang/compiler/stackir/instructions/InstructionMatchers.java
@@ -103,4 +103,8 @@ public class InstructionMatchers {
             ReturnInstruction.class
         );
     }
+
+    public static Matcher<Instruction> isStringAddInstruction() {
+        return instanceOf(StringAddInstruction.class);
+    }
 }
diff --git a/src/test/java/org/shedlang/compiler/stackir/instructions/Instructions.java b/src/test/java/org/shedlang/compiler/stackir/instructions/Instructions.java
index 6f769591..df8b193b 100644
--- a/src/test/java/org/shedlang/compiler/stackir/instructions/Instructions.java
+++ b/src/test/java/org/shedlang/compiler/stackir/instructions/Instructions.java
@@ -77,4 +77,8 @@ public class Instructions {
     public static Instruction return_() {
         return new ReturnInstruction(Sources.NULL);
     }
+
+    public static Instruction stringAdd() {
+        return new StringAddInstruction(Sources.NULL);
+    }
 }