Compile expression statements to stack instructions

3 files changed, 18 insertions, 1 deletions

diff --git a/src/main/java/org/shedlang/compiler/stackir/StackCompiler.java b/src/main/java/org/shedlang/compiler/stackir/StackCompiler.java
index c16674e0..4623bc5d 100644
--- a/src/main/java/org/shedlang/compiler/stackir/StackCompiler.java
+++ b/src/main/java/org/shedlang/compiler/stackir/StackCompiler.java
@@ -56,6 +56,17 @@ public class StackCompiler {
         };
     }
 
+    private static PVector<Instruction> compileExpressionStatement(TypedExpressionStatementNode node) {
+        return compileExpression(node.expression()).plus(new DiscardInstruction(node.source()));
+    }
+    
+    public static PVector<Instruction> compileFunctionStatement(TypedFunctionStatementNode node) {
+        return switch (node) {
+            case TypedExpressionStatementNode expressionStatement ->
+                compileExpressionStatement(expressionStatement);  
+        };
+    }
+
     private static PVector<Instruction> compileIntLiteral(TypedIntLiteralNode node) {
         return P.vector(new PushIntInstruction(node.value(), node.source()));
     }
diff --git a/src/main/java/org/shedlang/compiler/stackir/instructions/DiscardInstruction.java b/src/main/java/org/shedlang/compiler/stackir/instructions/DiscardInstruction.java
new file mode 100644
index 00000000..6efd3c03
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/stackir/instructions/DiscardInstruction.java
@@ -0,0 +1,6 @@
+package org.shedlang.compiler.stackir.instructions;
+
+import org.shedlang.compiler.sources.Source;
+
+public record DiscardInstruction(Source source) implements Instruction {
+}
diff --git a/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java b/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
index 33007bf2..0b5d9dd8 100644
--- a/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
+++ b/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
@@ -1,5 +1,5 @@
 package org.shedlang.compiler.stackir.instructions;
 
 public sealed interface Instruction
-    permits CallInstruction, LocalLoadInstruction, LocalStoreInstruction, PushBoolInstruction, PushIntInstruction, PushStringInstruction {
+    permits CallInstruction, DiscardInstruction, LocalLoadInstruction, LocalStoreInstruction, PushBoolInstruction, PushIntInstruction, PushStringInstruction {
 }