Create separate class for generating primitive methods in Python

1 files changed, 56 insertions, 0 deletions

diff --git a/src/main/java/org/zwobble/couscous/backends/python/PrimitiveMethods.java b/src/main/java/org/zwobble/couscous/backends/python/PrimitiveMethods.java
new file mode 100644
index 0000000..129fb19
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/backends/python/PrimitiveMethods.java
@@ -0,0 +1,56 @@
+package org.zwobble.couscous.backends.python;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import org.zwobble.couscous.backends.python.ast.PythonExpressionNode;
+import org.zwobble.couscous.values.StringValue;
+import org.zwobble.couscous.values.TypeReference;
+
+import com.google.common.collect.ImmutableMap;
+
+import static java.util.Arrays.asList;
+import static org.zwobble.couscous.backends.python.ast.PythonAttributeAccessNode.pythonAttributeAccess;
+import static org.zwobble.couscous.backends.python.ast.PythonCallNode.pythonCall;
+import static org.zwobble.couscous.backends.python.ast.PythonVariableReferenceNode.pythonVariableReference;
+
+public class PrimitiveMethods {
+    private static final Map<String, PrimitiveMethodGenerator> STRING_METHODS =
+        ImmutableMap.<String, PrimitiveMethodGenerator>builder()
+        
+            .put("length", (receiver, arguments) ->
+                pythonCall(
+                    pythonVariableReference("len"),
+                    asList(receiver)))
+            
+            .put("substring", (receiver, arguments) ->
+                pythonCall(
+                    pythonAttributeAccess(
+                        receiver,
+                        "__getitem__"),
+                    asList(pythonCall(
+                        pythonVariableReference("slice"),
+                    arguments))))
+            
+            .build();
+    
+    private static final Map<TypeReference, Map<String, PrimitiveMethodGenerator>> METHODS = 
+        ImmutableMap.<TypeReference, Map<String, PrimitiveMethodGenerator>>builder()
+            .put(StringValue.REF, STRING_METHODS)
+            .build();
+    
+    public static boolean isPrimitive(TypeReference type) {
+        return METHODS.containsKey(type);
+    }
+    
+    public static Optional<PrimitiveMethodGenerator> getPrimitiveMethod(TypeReference type, String methodName) {
+        return Optional.ofNullable(METHODS.get(type))
+            .flatMap(methodsForType -> Optional.ofNullable(methodsForType.get(methodName)));
+    }
+    
+    @FunctionalInterface
+    public interface PrimitiveMethodGenerator {
+        PythonExpressionNode generate(PythonExpressionNode receiver, List<PythonExpressionNode> arguments);
+    }
+}