Break the ground where we need to implement word table read/write.

HISTORY.markdown

@@ -6,6 +6,7 @@ History of SixtyPical
 
 *   Add word (constant or memory location) to word memory location.
 *   Add word to pointer (unchecked for now).
+*   Adding `word table` type (in progress).
 *   Implementation: `--debug` shows some extra info during analysis.
 *   Fixed bug where `copy`ing literal word into word storage used wrong endianness.
 

README.markdown

@@ -47,7 +47,7 @@ Compare word (constant or memory location) with memory location or pointer.  (Ma
 And then write a little demo "game" where you can move a block around the screen with
 the joystick.
 
-### `word table` and `vector table` types
+### `vector table` type
 
 ### `low` and `high` address operators
 
@@ -55,7 +55,7 @@ To turn `word` type into `byte`.
 
 ### save registers on stack
 
-This preserves them, so semantically, they can be used even though they
+This preserves them, so that, semantically, they can be used later even though they
 are trashed inside the block.
 
 ### And at some point...

eg/word-table.60p

@@ -0,0 +1,13 @@
+word one
+word table many
+
+routine main
+  inputs one, many
+  outputs one, many
+  trashes a, x, n, z
+{
+    ld x, 0
+    copy 777, one
+    copy one, many + x
+    copy many + x, one
+}

src/sixtypical/compiler.py

@@ -2,8 +2,8 @@
 
 from sixtypical.ast import Program, Routine, Block, Instr
 from sixtypical.model import (
-    ConstantRef, LocationRef, IndirectRef, AddressRef,
+    ConstantRef, LocationRef, IndexedRef, IndirectRef, AddressRef,
-    TYPE_BIT, TYPE_BYTE, TYPE_WORD, BufferType, PointerType, RoutineType, VectorType,
+    TYPE_BIT, TYPE_BYTE, TYPE_WORD, TYPE_WORD_TABLE, BufferType, PointerType, RoutineType, VectorType,
     REG_A, REG_X, REG_Y, FLAG_C
 )
 from sixtypical.emitter import Byte, Label, Offset, LowAddressByte, HighAddressByte
@@ -169,7 +169,7 @@ class Compiler(object):
                     raise UnsupportedOpcodeError(instr)
             elif isinstance(dest, LocationRef) and src.type == TYPE_WORD and isinstance(dest.type, PointerType):
                 if isinstance(src, ConstantRef):
-                    dest_label = self.labels[dest.name]  # this. is. zero-page.
+                    dest_label = self.labels[dest.name]
                     self.emitter.emit(LDA(ZeroPage(dest_label)))
                     self.emitter.emit(ADC(Immediate(Byte(src.low_byte()))))
                     self.emitter.emit(STA(ZeroPage(dest_label)))
@@ -178,7 +178,7 @@ class Compiler(object):
                     self.emitter.emit(STA(ZeroPage(Offset(dest_label, 1))))
                 elif isinstance(src, LocationRef):
                     src_label = self.labels[src.name]
-                    dest_label = self.labels[dest.name]  # this. is. zero-page.
+                    dest_label = self.labels[dest.name]
                     self.emitter.emit(LDA(ZeroPage(dest_label)))
                     self.emitter.emit(ADC(Absolute(src_label)))
                     self.emitter.emit(STA(ZeroPage(dest_label)))
@@ -345,6 +345,17 @@ class Compiler(object):
                 self.emitter.emit(STA(ZeroPage(dest_label)))
                 self.emitter.emit(LDA(Immediate(LowAddressByte(src_label))))
                 self.emitter.emit(STA(ZeroPage(Offset(dest_label, 1))))
+            elif isinstance(src, LocationRef) and isinstance(dest, IndexedRef):
+                if src.type == TYPE_WORD and dest.ref.type == TYPE_WORD_TABLE:
+                    src_label = self.labels[src.name]
+                    dest_label = self.labels[dest.ref.name]
+                    raise NotImplementedError("""\
+What we will need to do here, is to have TWO 'labels' per name, one for the high byte table,
+and one for the low byte table.  Then select AbsoluteX() or AbsoluteY() addressing on those
+tables.  And use that in the STA() part.""")
+                else:
+                    raise NotImplementedError
+
             elif not isinstance(src, (ConstantRef, LocationRef)) or not isinstance(dest, LocationRef):
                 raise NotImplementedError((src, dest))
             elif src.type == TYPE_BYTE and dest.type == TYPE_BYTE:

tests/SixtyPical Compilation.md

@@ -316,6 +316,23 @@ Copy routine to vector, inside an `interrupts off` block.
     | }
     = 00c078a90d8d0fc0a9c08d10c05860e860
 
+Copy word to word table and back.
+
+    | word one
+    | word table many
+    | 
+    | routine main
+    |   inputs one, many
+    |   outputs one, many
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     copy 777, one
+    |     copy one, many + x
+    |     copy many + x, one
+    | }
+    = 00c0a200a9009d0dc0bd0dc060....
+
 Indirect call.
 
     | vector foo outputs x trashes z, n