From 19a196f765d3dcd4603cfb83cffc1d6abc1c3f39 Mon Sep 17 00:00:00 2001
From: Chris Pressey <cpressey@catseye.tc>
Date: Fri, 24 Nov 2017 16:56:55 +0000
Subject: [PATCH] Compile copy[]+y.

---
 eg/buffer.60p                   |  2 +-
 src/sixtypical/compiler.py      | 10 ++++++++++
 src/sixtypical/gen6502.py       | 12 ++----------
 tests/SixtyPical Compilation.md | 17 ++++++++++++++++-
 4 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/eg/buffer.60p b/eg/buffer.60p
index 84cb784..5b63103 100644
--- a/eg/buffer.60p
+++ b/eg/buffer.60p
@@ -8,5 +8,5 @@ routine main
 {
     ld y, 0
     copy buf, ptr
-    // copy 123, [ptr] + y
+    copy 123, [ptr] + y
 }
diff --git a/src/sixtypical/compiler.py b/src/sixtypical/compiler.py
index a649b29..192f81f 100644
--- a/src/sixtypical/compiler.py
+++ b/src/sixtypical/compiler.py
@@ -322,5 +322,15 @@ class Compiler(object):
                 self.emitter.emit(STA(Absolute(Offset(dest_label, 1))))
             else:
                 raise NotImplementedError(src.type)
+        elif opcode == 'copy[]+y':
+            if src.type == TYPE_BYTE and isinstance(dest.type, PointerType):
+                if isinstance(src, ConstantRef):
+                    dest_label = self.labels[dest.name]
+                    self.emitter.emit(LDA(Immediate(Byte(src.value))))
+                    self.emitter.emit(STA(IndirectY(dest_label)))
+                else:
+                    raise NotImplementedError((src.type, dest.type))
+            else:
+                raise NotImplementedError((src.type, dest.type))
         else:
             raise NotImplementedError(opcode)
diff --git a/src/sixtypical/gen6502.py b/src/sixtypical/gen6502.py
index b72471e..8659ab6 100644
--- a/src/sixtypical/gen6502.py
+++ b/src/sixtypical/gen6502.py
@@ -82,16 +82,8 @@ class Indirect(AddressingMode):
         return self.value.serialize()
 
 
-class IndirectY(AddressingMode):
-    def __init__(self, value):
-        assert isinstance(value, Label)
-        self.value = value
-
-    def size(self):
-        return 1
-
-    def serialize(self, addr=None):
-        return self.value.serialize()
+class IndirectY(ZeroPage):
+    pass
 
 
 class Relative(AddressingMode):
diff --git a/tests/SixtyPical Compilation.md b/tests/SixtyPical Compilation.md
index b001f53..5e2df28 100644
--- a/tests/SixtyPical Compilation.md	
+++ b/tests/SixtyPical Compilation.md	
@@ -354,6 +354,21 @@ Buffers and pointers.
     | {
     |     ld y, 0
     |     copy buf, ptr
-    |     // copy 123, [ptr] + y
     | }
     = 00c0a000a90b85fea9c085ff60
+
+Writing through a pointer.
+
+    | buffer[2048] buf
+    | pointer ptr @ 254
+    | 
+    | routine main
+    |   inputs buf
+    |   outputs buf, y
+    |   trashes a, z, n, ptr
+    | {
+    |     ld y, 0
+    |     copy buf, ptr
+    |     copy 123, [ptr] + y
+    | }
+    = 00c0a000a90f85fea9c085ffa97b91fe60