Add tuple-get instruction

5 files changed, 27 insertions, 3 deletions

diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
index 3332a117..e6e3ba0a 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
@@ -471,6 +471,10 @@ public class PatioCodeGen {
                 throw new UnsupportedOperationException("TODO");
             }
 
+            case TupleGetInstruction tupleGet -> {
+                throw new UnsupportedOperationException("TODO");
+            }
+
             case VarLoadInstruction varLoad -> {
                 var varValueResult = context.allocateVal(
                     PatioCodeGenLocalSpace.VAR_VALUE,
diff --git a/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java b/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java
index d2dfc37b..875dbcec 100644
--- a/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java
+++ b/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java
@@ -177,6 +177,12 @@ public class InstructionSerializer {
                     treeInt(tupleCreateInstruction.elementCount())
                 );
 
+            case TupleGetInstruction tupleGetInstruction ->
+                treeList(
+                    treeIdentifier("tuple-get"),
+                    treeInt(tupleGetInstruction.elementIndex())
+                );
+
             case VarLoadInstruction varLoadInstruction ->
                 treeList(
                     treeIdentifier("var-load"),
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 25b14e93..29703869 100644
--- a/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
+++ b/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
@@ -3,7 +3,7 @@ package org.shedlang.compiler.stackir.instructions;
 import org.shedlang.compiler.sources.Source;
 
 public sealed interface Instruction
-    permits CallInstruction, DefineFunctionInstruction, DiscardInstruction, FieldLoadInstruction, IfInstruction, IntAddInstruction, IntEqualsInstruction, IntNotEqualInstruction, IntSubInstruction, LocalLoadInstruction, LocalStoreInstruction, LoopBreakInstruction, LoopContinueInstruction, LoopInstruction, NamespaceFieldStoreInstruction, NamespaceImportInstruction, PushBoolInstruction, PushIntInstruction, PushStringInstruction, PushUnitInstruction, ReturnInstruction, StringAddInstruction, TupleCreateInstruction, VarLoadInstruction, VarStoreInstruction {
+    permits CallInstruction, DefineFunctionInstruction, DiscardInstruction, FieldLoadInstruction, IfInstruction, IntAddInstruction, IntEqualsInstruction, IntNotEqualInstruction, IntSubInstruction, LocalLoadInstruction, LocalStoreInstruction, LoopBreakInstruction, LoopContinueInstruction, LoopInstruction, NamespaceFieldStoreInstruction, NamespaceImportInstruction, PushBoolInstruction, PushIntInstruction, PushStringInstruction, PushUnitInstruction, ReturnInstruction, StringAddInstruction, TupleCreateInstruction, TupleGetInstruction, VarLoadInstruction, VarStoreInstruction {
 
     Source source();
 }
diff --git a/src/main/java/org/shedlang/compiler/stackir/instructions/TupleCreateInstruction.java b/src/main/java/org/shedlang/compiler/stackir/instructions/TupleCreateInstruction.java
index 0888d947..d1dec767 100644
--- a/src/main/java/org/shedlang/compiler/stackir/instructions/TupleCreateInstruction.java
+++ b/src/main/java/org/shedlang/compiler/stackir/instructions/TupleCreateInstruction.java
@@ -3,8 +3,9 @@ package org.shedlang.compiler.stackir.instructions;
 import org.shedlang.compiler.sources.Source;
 
 /**
- * Pop {@code elementCount} values from the stack and create a tuple from those
- * elements. Elements should have been pushed onto the stack in index order.
+ * Pop {@code elementCount} values from the stack, create a tuple from those
+ * elements, and push the tuple onto the stack. Elements should have been pushed
+ * onto the stack in index order.
  */
 public record TupleCreateInstruction(
     int elementCount,
diff --git a/src/main/java/org/shedlang/compiler/stackir/instructions/TupleGetInstruction.java b/src/main/java/org/shedlang/compiler/stackir/instructions/TupleGetInstruction.java
new file mode 100644
index 00000000..b621a336
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/stackir/instructions/TupleGetInstruction.java
@@ -0,0 +1,13 @@
+package org.shedlang.compiler.stackir.instructions;
+
+import org.shedlang.compiler.sources.Source;
+
+/**
+ * Pop a tuple from the stack, get the element at the given index, and push it
+ * onto the stack.
+ */
+public record TupleGetInstruction(
+    int elementIndex,
+    Source source
+) implements Instruction {
+}