Add Patio code gen for struct field accesses

5 files changed, 81 insertions, 16 deletions

diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
index 0c6f94f2..9382eab7 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
@@ -281,7 +281,14 @@ public class PatioCodeGen {
                     }
 
                     case FieldLoadInstruction.Receiver.Struct receiverStruct -> {
-                        throw new UnsupportedOperationException("TODO");
+                        context = PatioCodeGenStructs.fieldLoad(
+                            target,
+                            receiver,
+                            receiverStruct.type(),
+                            fieldLoad.fieldName(),
+                            fieldLoad.source(),
+                            context
+                        );
                     }
                 }
 
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java
index d99f3ce6..4d6ece42 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGenStructs.java
@@ -1,10 +1,7 @@
 package org.shedlang.compiler.patio;
 
 import org.shedlang.compiler.ast.typed.FreeVariables;
-import org.shedlang.compiler.patio.ast.instructions.PatioAllocHeap;
-import org.shedlang.compiler.patio.ast.instructions.PatioDataPtrToInt;
-import org.shedlang.compiler.patio.ast.instructions.PatioMemoryStore;
-import org.shedlang.compiler.patio.ast.instructions.PatioReturn;
+import org.shedlang.compiler.patio.ast.instructions.*;
 import org.shedlang.compiler.patio.ast.operands.PatioLocalRef;
 import org.shedlang.compiler.patio.ast.types.PatioDataLayout;
 import org.shedlang.compiler.patio.ast.types.PatioDataLayouts;
@@ -44,7 +41,7 @@ public class PatioCodeGenStructs {
                 var valuePointer = valuePointerResult.value();
                 bodyContext = valuePointerResult.context();
 
-                var structDataLayout = structDataLayout(fields);
+                var structDataLayout = structDataLayout(type, context);
 
                 bodyContext = bodyContext.addInstruction(new PatioAllocHeap(
                     valuePointer,
@@ -87,12 +84,52 @@ public class PatioCodeGenStructs {
         );
     }
 
+    public static PatioCodeGenContext fieldLoad(
+        PatioLocalRef target,
+        PatioLocalRef receiver,
+        StructType type,
+        String fieldName,
+        Source source,
+        PatioCodeGenContext context
+    ) {
+        var valuePointerResult = context.allocateVal(
+            PatioCodeGenLocalSpace.STRUCT_VALUE_POINTER,
+            PatioTypes.DATA_POINTER
+        );
+        var valuePointer = valuePointerResult.value();
+        context = valuePointerResult.context();
+
+        context = context.addInstruction(new PatioIntToDataPtr(
+            valuePointer,
+            receiver,
+            source
+        ));
+
+        var structDataLayout = structDataLayout(type, context);
+
+        var structTypeInfo = context.structTypeInfo(type);
+        var fieldIndex = structTypeInfo.fieldIndex(fieldName);
+
+        context = context.addInstruction(new PatioMemoryLoad(
+            target,
+            valuePointer,
+            structDataLayout,
+            List.of(fieldIndex),
+            source
+        ));
+
+        return context;
+    }
+
     private static PatioDataLayout structDataLayout(
-        List<DefineStructInstruction.Field> fields
+        StructType type,
+        PatioCodeGenContext context
     ) {
+        var structTypeInfo = context.structTypeInfo(type);
+
         return PatioDataLayouts.struct(Lists.repeat(
             PatioDataLayouts.INT,
-            fields.size()
+            structTypeInfo.fields().size()
         ));
     }
 }
diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index dc25bfc3..81917dfb 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -1,11 +1,10 @@
 package org.shedlang.compiler.typechecker;
 
-import org.pcollections.OrderedPMap;
 import org.shedlang.compiler.ast.typed.*;
 import org.shedlang.compiler.ast.untyped.*;
 import org.shedlang.compiler.sources.Source;
-import org.shedlang.compiler.typechecker.errors.*;
 import org.shedlang.compiler.typechecker.errors.NoSuchFieldError;
+import org.shedlang.compiler.typechecker.errors.*;
 import org.shedlang.compiler.typechecker.typesets.TypeSetTypeLevelValue;
 import org.shedlang.compiler.typechecker.typesets.TypeSets;
 import org.shedlang.compiler.types.*;
@@ -323,7 +322,7 @@ public class TypeChecker {
         ) {
             var structTypeInfo = context.structTypeInfo(structType, typedReceiver.source());
 
-            var namedParams = structTypeInfo.fields().entrySet().stream()
+            var namedParams = structTypeInfo.fields().entryStream()
                 .map(field -> {
                     var name = field.getKey();
                     var type = field.getValue();
@@ -859,7 +858,7 @@ public class TypeChecker {
             @Override
             public TypeCheckerContext defineTypes(TypeCheckerContext context) {
                 var typedFieldNodes = new ArrayList<TypedStructFieldDefinitionNode>();
-                var fieldTypes = OrderedPMap.<String, Type>empty();
+                var fieldTypes = P.<String, Type>orderedMap();
 
                 for (var untypedField : untyped.fields()) {
                     var typedFieldNode = new TypedStructFieldDefinitionNode(
diff --git a/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java b/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java
index f0c3eff7..7a95a234 100644
--- a/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java
+++ b/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java
@@ -1,11 +1,22 @@
 package org.shedlang.compiler.types;
 
-import org.pcollections.OrderedPMap;
+import org.shedlang.compiler.util.POrderedMap;
 
 import java.util.Optional;
 
-public record StructTypeInfo(OrderedPMap<String, Type> fields) {
+public record StructTypeInfo(POrderedMap<String, Type> fields) {
     public Optional<Type> fieldType(String fieldName) {
-        return Optional.ofNullable(this.fields.get(fieldName));
+        return this.fields.get(fieldName);
+    }
+
+    public int fieldIndex(String fieldName) {
+        // TODO: extract common field set from namespace type info
+        var fieldIndex = fields.keys().indexOf(fieldName);
+
+        if (fieldIndex == -1) {
+            throw new NoSuchFieldInternalError(fieldName);
+        } else {
+            return fieldIndex;
+        }
     }
 }
diff --git a/src/main/java/org/shedlang/compiler/util/POrderedMap.java b/src/main/java/org/shedlang/compiler/util/POrderedMap.java
index 3ab74270..4a8780ad 100644
--- a/src/main/java/org/shedlang/compiler/util/POrderedMap.java
+++ b/src/main/java/org/shedlang/compiler/util/POrderedMap.java
@@ -4,7 +4,9 @@ import org.pcollections.Empty;
 import org.pcollections.PMap;
 import org.pcollections.PVector;
 
-import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Stream;
 
 public class POrderedMap<K, V> {
     public static <K, V> POrderedMap<K, V> empty() {
@@ -42,6 +44,10 @@ public class POrderedMap<K, V> {
         return keys;
     }
 
+    public Optional<V> get(K key) {
+        return Optional.ofNullable(map.get(key));
+    }
+
     public PVector<V> toValues() {
         return keys.stream()
             .map(key -> map.get(key))
@@ -52,6 +58,11 @@ public class POrderedMap<K, V> {
         return keys.size();
     }
 
+    public Stream<Map.Entry<K, V>> entryStream() {
+        return keys.stream()
+            .map(key -> Map.entry(key, map.get(key)));
+    }
+
     @Override
     public boolean equals(Object other) {
         if (this == other) {