Machine model is a bit fuller now.

README.markdown

@@ -92,11 +92,39 @@ that has a natural symmetrical opcode (e.g. `pha`, `sei`).  These instructions
 take a block.  The natural symmetrical opcode is inserted at the end of the
 block.
 
+### Loops ###
+
+Still need to figure this out.
+
+Typical `repeat` loop looks like:
+
+    ldy #0
+    _loop:
+    lda #65
+    sta screen, y
+    iny
+    cpy #250
+    bne _loop
+
+This might be
+
+    routine blah {
+        ldy# 0
+        repeat bne {
+            lda# 65
+            sta,y screen
+            iny
+            cpy# 250
+        }
+    }
+
+Note, `screen` must be a `byte table` here.
+
 TODO
 ----
 
 *   Parse HEX values like $40A3
-*   Full machine model
+*   Fuller machine model
 *   Addressing modes; rename instructions to match
 
 Tests

src/SixtyPical/Analyzer.hs

@@ -9,11 +9,11 @@ import SixtyPical.Model
 -- -- -- -- data-flow-analysis context -- -- -- --
 
 data Usage = Unknown
-           | Value LocationName -- obviously a bit daft for now
-           | Retained Register
+           | Value StorageLocation -- obviously a bit daft for now
+           | Retained StorageLocation
     deriving (Show, Ord, Eq)
 
-type RoutineContext = Map.Map Register Usage
+type RoutineContext = Map.Map StorageLocation Usage
 
 type ProgramContext = Map.Map RoutineName RoutineContext
 

src/SixtyPical/Checker.hs

@@ -21,14 +21,16 @@ locationDeclared locName (Program decls _) =
     elem locName (map (getDeclLocationName) decls)
     where
 
+-- in the following, we mean Named locations
+
 routineUsedLocations (Routine _ instrs) = blockUsedLocations instrs
 
 blockUsedLocations [] = []
 blockUsedLocations (instr:instrs) =
     (instrUsedLocations instr) ++ blockUsedLocations instrs
 
-instrUsedLocations (LOAD reg loc) = [loc]
-instrUsedLocations (CMP reg loc) = [loc]
+instrUsedLocations (LOAD reg (NamedLocation loc)) = [loc]
+instrUsedLocations (CMP reg (NamedLocation loc)) = [loc]
 -- TODO: JSR...
 instrUsedLocations (IFEQ b1 b2) =
     blockUsedLocations b1 ++ blockUsedLocations b2

src/SixtyPical/Emitter.hs

@@ -35,10 +35,10 @@ emitInstrs _ _ [] = ""
 emitInstrs p r (instr:instrs) =
     "  " ++ emitInstr p r instr ++ "\n" ++ emitInstrs p r instrs
 
-emitInstr p r (LOAD A label) = "lda " ++ label
-emitInstr p r (LOAD X label) = "ldx " ++ label
-emitInstr p r (LOAD Y label) = "ldy " ++ label
-emitInstr p r (CMP A label) = "cmp " ++ label
+emitInstr p r (LOAD A (NamedLocation label)) = "lda " ++ label
+emitInstr p r (LOAD X (NamedLocation label)) = "ldx " ++ label
+emitInstr p r (LOAD Y (NamedLocation label)) = "ldy " ++ label
+emitInstr p r (CMP A (NamedLocation label)) = "cmp " ++ label
 
 emitInstr p r (COPY A X) = "tax"
 emitInstr p r (COPY A Y) = "tay"

src/SixtyPical/Model.hs

@@ -8,10 +8,30 @@ type Address = Int -- LET'S ASSUME THIS IS AT LEAST 16 BITS
 
 type LocationName = String
 
-data Register = A | X | Y    -- | MemLoc LocationName
+-- We do not include the PC as it of course changes constantly.
+-- We do not include the stack pointer, as it should not change over
+-- the lifetime of a single routine.  (Always pop what you pushed.)
+-- Ditto the I flag.  (always enable interrupts after disabling them.)
+-- We do not include the B flag, because for us, BRK is game over, man.
+
+-- One of these should never refer to the program code.  We can only police
+-- this up to a point.
+
+data StorageLocation = A
+              | Y
+              | X
+              | FlagN
+              | FlagV
+              | FlagD
+              | FlagZ
+              | FlagC
+              | NamedLocation LocationName
     deriving (Show, Ord, Eq)
 
-allRegisters = [A, X, Y]
+-- this is bunk, man.  if a location does not appear in an analysis
+-- map the meaning should be taken to be "preserved".
+
+allRegisters = [A, X, Y, FlagN, FlagV, FlagD, FlagZ, FlagC]
 
 -- -- -- -- program model -- -- -- --
 
@@ -25,9 +45,9 @@ data Decl = Assign LocationName Size Address -- .alias
 
 type RoutineName = String
 
-data Instruction = LOAD Register LocationName
-                 | COPY Register Register
-                 | CMP Register LocationName
+data Instruction = LOAD StorageLocation StorageLocation
+                 | COPY StorageLocation StorageLocation
+                 | CMP StorageLocation StorageLocation
                  | JSR RoutineName
                  | IFEQ [Instruction] [Instruction]
                  | NOP

src/SixtyPical/Parser.hs

@@ -88,28 +88,28 @@ cmp = do
     string "cmp"
     spaces
     l <- locationName
-    return (CMP A l)
+    return (CMP A (NamedLocation l))
 
 lda :: Parser Instruction
 lda = do
     string "lda"
     spaces
     l <- locationName
-    return (LOAD A l)
+    return (LOAD A (NamedLocation l))
 
 ldx :: Parser Instruction
 ldx = do
     string "ldx"
     spaces
     l <- locationName
-    return (LOAD X l)
+    return (LOAD X (NamedLocation l))
 
 ldy :: Parser Instruction
 ldy = do
     string "ldy"
     spaces
     l <- locationName
-    return (LOAD Y l)
+    return (LOAD Y (NamedLocation l))
 
 txa :: Parser Instruction
 txa = do