Refine the AST classes even more.

src/sixtypical/analyzer.py

@@ -1,6 +1,6 @@
 # encoding: UTF-8
 
-from sixtypical.ast import Program, Routine, Block, Instr, SingleOp, BlockOp, IfOp
+from sixtypical.ast import Program, Routine, Block, Instr, SingleOp, If, Repeat, WithInterruptsOff
 from sixtypical.model import (
     TYPE_BYTE, TYPE_WORD,
     TableType, BufferType, PointerType, VectorType, RoutineType,
@@ -313,11 +313,13 @@ class Analyzer(object):
 
     def analyze_instr(self, instr, context):
         if isinstance(instr, SingleOp):
-            return self.analyze_single_op(instr, context)
-        elif isinstance(instr, BlockOp):
-            return self.analyze_block_op(instr, context)
-        elif isinstance(instr, IfOp):
-            return self.analyze_if_op(instr, context)
+            self.analyze_single_op(instr, context)
+        elif isinstance(instr, If):
+            self.analyze_if(instr, context)
+        elif isinstance(instr, Repeat):
+            self.analyze_repeat(instr, context)
+        elif isinstance(instr, WithInterruptsOff):
+            self.analyze_block(instr.block, context)
         else:
             raise NotImplementedError
 
@@ -547,7 +549,7 @@ class Analyzer(object):
         else:
             raise NotImplementedError(opcode)
 
-    def analyze_if_op(self, instr, context):
+    def analyze_if(self, instr, context):
         incoming_meaningful = set(context.each_meaningful())
 
         context1 = context.clone()
@@ -586,20 +588,15 @@ class Analyzer(object):
             context.set_touched(ref)
             context.set_unmeaningful(ref)
 
-    def analyze_block_op(self, instr, context):
-        if instr.opcode == 'repeat':
-            # it will always be executed at least once, so analyze it having
-            # been executed the first time.
-            self.analyze_block(instr.block, context)
-            if instr.src is not None:  # None indicates 'repeat forever'
-                context.assert_meaningful(instr.src)
+    def analyze_repeat(self, instr, context):
+        # it will always be executed at least once, so analyze it having
+        # been executed the first time.
+        self.analyze_block(instr.block, context)
+        if instr.src is not None:  # None indicates 'repeat forever'
+            context.assert_meaningful(instr.src)
 
-            # now analyze it having been executed a second time, with the context
-            # of it having already been executed.
-            self.analyze_block(instr.block, context)
-            if instr.src is not None:
-                context.assert_meaningful(instr.src)
-        elif instr.opcode == 'with-sei':
-            self.analyze_block(instr.block, context)
-        else:
-            raise NotImplementedError(opcode)
+        # now analyze it having been executed a second time, with the context
+        # of it having already been executed.
+        self.analyze_block(instr.block, context)
+        if instr.src is not None:
+            context.assert_meaningful(instr.src)

src/sixtypical/ast.py

@@ -72,11 +72,15 @@ class SingleOp(Instr):
     value_attrs = ('opcode', 'dest', 'src', 'location',)
 
 
-class BlockOp(Instr):
-    value_attrs = ('opcode', 'src', 'inverted')
+class If(Instr):
+    value_attrs = ('src', 'inverted')
+    child_attrs = ('block1', 'block2',)
+
+
+class Repeat(Instr):
+    value_attrs = ('src', 'inverted')
     child_attrs = ('block',)
 
 
-class IfOp(Instr):
-    value_attrs = ('src', 'inverted')
-    child_attrs = ('block1', 'block2',)
+class WithInterruptsOff(Instr):
+    child_attrs = ('block',)

src/sixtypical/compiler.py

@@ -1,6 +1,6 @@
 # encoding: UTF-8
 
-from sixtypical.ast import Program, Routine, Block, Instr, SingleOp, BlockOp, IfOp
+from sixtypical.ast import Program, Routine, Block, Instr, SingleOp, If, Repeat, WithInterruptsOff
 from sixtypical.model import (
     ConstantRef, LocationRef, IndexedRef, IndirectRef, AddressRef,
     TYPE_BIT, TYPE_BYTE, TYPE_WORD,
@@ -144,10 +144,12 @@ class Compiler(object):
     def compile_instr(self, instr):
         if isinstance(instr, SingleOp):
             return self.compile_single_op(instr)
-        elif isinstance(instr, BlockOp):
-            return self.compile_block_op(instr)
-        elif isinstance(instr, IfOp):
-            return self.compile_if_op(instr)
+        elif isinstance(instr, If):
+            return self.compile_if(instr)
+        elif isinstance(instr, Repeat):
+            return self.compile_repeat(instr)
+        elif isinstance(instr, WithInterruptsOff):
+            return self.compile_with_interrupts_off(instr)
         else:
             raise NotImplementedError
 
@@ -493,7 +495,7 @@ class Compiler(object):
         else:
             raise NotImplementedError(src.type)
 
-    def compile_if_op(self, instr):
+    def compile_if(self, instr):
         cls = {
             False: {
                 'c': BCC,
@@ -518,29 +520,27 @@ class Compiler(object):
         else:
             self.emitter.resolve_label(else_label)
 
-    def compile_block_op(self, instr):
-        if instr.opcode == 'repeat':
-            top_label = self.emitter.make_label()
-            self.compile_block(instr.block)
-            if instr.src is None:  # indicates 'repeat forever'
-                self.emitter.emit(JMP(Absolute(top_label)))
-            else:
-                cls = {
-                    False: {
-                        'c': BCC,
-                        'z': BNE,
-                    },
-                    True: {
-                        'c': BCS,
-                        'z': BEQ,
-                    },
-                }[instr.inverted].get(instr.src.name)
-                if cls is None:
-                    raise UnsupportedOpcodeError(instr)
-                self.emitter.emit(cls(Relative(top_label)))
-        elif instr.opcode == 'with-sei':
-            self.emitter.emit(SEI())
-            self.compile_block(instr.block)
-            self.emitter.emit(CLI())
+    def compile_repeat(self, instr):
+        top_label = self.emitter.make_label()
+        self.compile_block(instr.block)
+        if instr.src is None:  # indicates 'repeat forever'
+            self.emitter.emit(JMP(Absolute(top_label)))
         else:
-            raise NotImplementedError(opcode)
+            cls = {
+                False: {
+                    'c': BCC,
+                    'z': BNE,
+                },
+                True: {
+                    'c': BCS,
+                    'z': BEQ,
+                },
+            }[instr.inverted].get(instr.src.name)
+            if cls is None:
+                raise UnsupportedOpcodeError(instr)
+            self.emitter.emit(cls(Relative(top_label)))
+
+    def compile_with_interrupts_off(self, instr):
+        self.emitter.emit(SEI())
+        self.compile_block(instr.block)
+        self.emitter.emit(CLI())

src/sixtypical/parser.py

@@ -1,6 +1,6 @@
 # encoding: UTF-8
 
-from sixtypical.ast import Program, Defn, Routine, Block, SingleOp, BlockOp, IfOp
+from sixtypical.ast import Program, Defn, Routine, Block, SingleOp, If, Repeat, WithInterruptsOff
 from sixtypical.model import (
     TYPE_BIT, TYPE_BYTE, TYPE_WORD,
     RoutineType, VectorType, TableType, BufferType, PointerType,
@@ -355,7 +355,7 @@ class Parser(object):
             block2 = None
             if self.scanner.consume('else'):
                 block2 = self.block()
-            return IfOp(src=src, block1=block1, block2=block2, inverted=inverted)
+            return If(src=src, block1=block1, block2=block2, inverted=inverted)
         elif self.scanner.consume('repeat'):
             inverted = False
             src = None
@@ -366,7 +366,7 @@ class Parser(object):
                 src = self.locexpr()
             else:
                 self.scanner.expect('forever')
-            return BlockOp(opcode='repeat', src=src, block=block, inverted=inverted)
+            return Repeat(src=src, block=block, inverted=inverted)
         elif self.scanner.token in ("ld",):
             # the same as add, sub, cmp etc below, except supports an indlocexpr for the src
             opcode = self.scanner.token
@@ -415,7 +415,7 @@ class Parser(object):
             self.scanner.expect("interrupts")
             self.scanner.expect("off")
             block = self.block()
-            return BlockOp(opcode='with-sei', src=None, block=block)
+            return WithInterruptsOff(block=block)
         elif self.scanner.consume("trash"):
             dest = self.locexpr()
             return SingleOp(opcode='trash', src=None, dest=dest)