The evaluator doesn't add much and keeps falling behind; remove it.

HISTORY.md

@@ -8,6 +8,7 @@ History of SixtyPical
 *   Initialized `byte table` values need not have all 256 bytes initialized.
 *   Constraints for `vector` type come immediately after the type, not the variable.
 *   `vector table` storage, and ability to copy vectors in and out of same.
+*   Removed the evaluator.  The reference implementation only analyzes and compiles.
 *   Fixed bug where index register wasn't required to be initialized before table access.
 
 0.10

README.md

@@ -21,8 +21,8 @@ based on common machine-language programming idioms, such as
 *   explicit tail calls
 *   indirect subroutine calls
 
-The reference implementation can execute, analyze, and compile SixtyPical
+The reference implementation can analyze and compile SixtyPical programs to
-programs to 6502 machine code.
+6502 machine code.
 
 Documentation
 -------------
@@ -45,8 +45,6 @@ Finish the little demo "game" where you can move a block around the screen with
 the joystick (i.e. bring it up to par with the original demo game that was written
 for SixtyPical)
 
-### `vector table` type
-
 ### `low` and `high` address operators
 
 To turn `word` type into `byte`.

bin/sixtypical

@@ -2,7 +2,7 @@
 
 """Usage: sixtypical [OPTIONS] FILES
 
-Analyzes and/or executes and/or compiles a Sixtypical program.
+Analyzes and compiles a Sixtypical program.
 """
 
 from os.path import realpath, dirname, join
@@ -19,7 +19,6 @@ import sys
 import traceback
 
 from sixtypical.parser import Parser
-from sixtypical.evaluator import Evaluator
 from sixtypical.analyzer import Analyzer
 from sixtypical.emitter import Emitter, Byte, Word
 from sixtypical.compiler import Compiler
@@ -43,9 +42,6 @@ if __name__ == '__main__':
     optparser.add_option("--traceback",
                          action="store_true",
                          help="")
-    optparser.add_option("--execute",
-                         action="store_true",
-                         help="")
 
     (options, args) = optparser.parse_args(sys.argv[1:])
 
@@ -88,7 +84,3 @@ if __name__ == '__main__':
                 pprint(emitter.accum)
             else:
                 emitter.serialize(fh)
-
-        if options.execute:
-            context = Evaluator().eval_program(program)
-            print str(context)

doc/SixtyPical.md

@@ -2,8 +2,9 @@ SixtyPical
 ==========
 
 This document describes the SixtyPical programming language version 0.11,
-both its execution aspect and its static analysis aspect (even though
+both its static semantics (the capabilities and limits of the static
-these are, technically speaking, separate concepts.)
+analyses it defines) and its runtime semantics (with reference to the
+semantics of 6502 machine code.)
 
 This document is nominally normative, but the tests in the `tests` directory
 are even more normative.

src/sixtypical/evaluator.py

@@ -1,208 +0,0 @@
-# encoding: UTF-8
-
-from sixtypical.ast import Program, Routine, Block, Instr
-from sixtypical.model import (
-    ConstantRef, LocationRef, PartRef, IndirectRef,
-    REG_A, REG_X, REG_Y, FLAG_Z, FLAG_N, FLAG_V, FLAG_C
-)
-
-
-class Context(object):
-    def __init__(self):
-        self._store = {}
-
-    def __str__(self):
-        return '\n'.join("%s: %s" % (name, value)
-                         for (name, value) in sorted(self._store.iteritems())
-                         if not isinstance(value, Routine))
-
-    def get(self, ref):
-        if isinstance(ref, ConstantRef):
-            return ref.value
-        elif isinstance(ref, LocationRef):
-            return self._store[ref.name]
-        elif isinstance(ref, PartRef):
-            value = self.get(ref.ref)
-            if ref.height == 0:
-                return value & 255
-            elif ref.height == 1:
-                return (value >> 8) & 255
-            else:
-                raise NotImplementedError
-        else:
-            raise ValueError(ref)
-
-    def set(self, ref, value):
-        if isinstance(ref, PartRef):
-            old = self.get(ref.ref)
-            if ref.height == 0:
-                value = (old & (255 << 8)) | value
-            elif ref.height == 1:
-                value = (value << 8) | (old & 255)
-            else:
-                raise NotImplementedError
-            ref = ref.ref
-        assert isinstance(ref, LocationRef)
-        self._store[ref.name] = value
-
-
-class Evaluator(object):
-
-    def eval_program(self, program):
-        assert isinstance(program, Program)
-        context = Context()
-        for ref in (REG_A, REG_X, REG_Y, FLAG_Z, FLAG_N, FLAG_V, FLAG_C):
-            context.set(ref, 0)
-        main = None
-
-        for defn in program.defns:
-            if defn.initial is not None:
-                context.set(defn.location, defn.initial)
-
-        for routine in program.routines:
-            context.set(routine.location, routine)
-            if routine.name == 'main':
-                main = routine
-
-        self.eval_routine(main, context)
-        return context
-
-    def eval_routine(self, routine, context):
-        assert isinstance(routine, Routine)
-        self.next_routine = routine
-        while self.next_routine:
-            routine = self.next_routine
-            self.next_routine = None
-            self.eval_block(routine.block, context)
-
-    def eval_block(self, block, context):
-        assert isinstance(block, Block)
-        for i in block.instrs:
-            self.eval_instr(i, context)
-            if self.next_routine:
-                break
-
-    def eval_instr(self, instr, context):
-        assert isinstance(instr, Instr)
-        opcode = instr.opcode
-        dest = instr.dest
-        src = instr.src
-
-        if opcode == 'ld':
-            result = context.get(src)
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'st':
-            context.set(dest, context.get(src))
-        elif opcode == 'add':
-            carry = context.get(FLAG_C)
-            val = context.get(src)
-            now = context.get(dest)
-            result = now + val + carry
-            if result > 255:
-                result &= 255
-                context.set(FLAG_C, 1)
-            else:
-                context.set(FLAG_C, 0)
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'sub':
-            carry = context.get(FLAG_C)
-            val = context.get(src)
-            now = context.get(dest)
-            result = now - val - carry
-            if result < 0:
-                result &= 255
-                context.set(FLAG_C, 1)
-            else:
-                context.set(FLAG_C, 0)
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'inc':
-            val = context.get(dest)
-            result = (val + 1) & 255
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'dec':
-            val = context.get(dest)
-            result = (val - 1) & 255
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'cmp':
-            val = context.get(src)
-            now = context.get(dest)
-            result = now - val
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            if result < 0:
-                result &= 255
-                context.set(FLAG_C, 1)
-            else:
-                context.set(FLAG_C, 0)
-        elif opcode == 'and':
-            result = context.get(dest) & context.get(src)
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'or':
-            result = context.get(dest) | context.get(src)
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'xor':
-            result = context.get(dest) ^ context.get(src)
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'shl':
-            val = context.get(dest)
-            carry = context.get(FLAG_C)
-            context.set(FLAG_C, 1 if val & 128 else 0)
-            result = ((val << 1) + carry) & 255
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'shr':
-            val = context.get(dest)
-            carry = context.get(FLAG_C)
-            context.set(FLAG_C, 1 if val & 1 else 0)
-            result = (val >> 1) + (carry * 128)
-            context.set(FLAG_Z, 1 if result == 0 else 0)
-            context.set(FLAG_N, 1 if result & 128 else 0)
-            context.set(dest, result)
-        elif opcode == 'call':
-            self.eval_routine(context.get(instr.location), context)
-        elif opcode == 'goto':
-            self.next_routine = context.get(instr.location)
-        elif opcode == 'if':
-            val = context.get(src)
-            test = (val != 0) if not instr.inverted else (val == 0)
-            if test:
-                self.eval_block(instr.block1, context)
-            elif instr.block2:
-                self.eval_block(instr.block2, context)
-        elif opcode == 'repeat':
-            self.eval_block(instr.block, context)
-            while context.get(src) == 0:
-                self.eval_block(instr.block, context)
-        elif opcode == 'copy':
-            if isinstance(src, IndirectRef):
-                raise NotImplementedError("this doesn't actually work")
-                src = src.ref
-            if isinstance(dest, IndirectRef):
-                raise NotImplementedError("this doesn't actually work")
-                dest = dest.ref
-            context.set(dest, context.get(src))
-            # these are trashed; so could be anything really
-            context.set(REG_A, 0)
-            context.set(FLAG_Z, 0)
-            context.set(FLAG_N, 0)
-        elif opcode == 'with-sei':
-            self.eval_block(instr.block)
-        else:
-            raise NotImplementedError

test.sh

@@ -2,6 +2,5 @@
 
 falderal --substring-error \
     tests/SixtyPical\ Syntax.md \
-    tests/SixtyPical\ Execution.md \
     tests/SixtyPical\ Analysis.md \
     tests/SixtyPical\ Compilation.md

tests/SixtyPical Execution.md

@@ -1,490 +0,0 @@
-SixtyPical Execution
-====================
-
-This is a test suite, written in [Falderal][] format, for the dynamic
-execution behaviour of the Sixtypical language, disgregarding static analysis.
-
-[Falderal]:     http://catseye.tc/node/Falderal
-
-    -> Functionality "Execute SixtyPical program" is implemented by
-    -> shell command "bin/sixtypical --execute %(test-body-file)"
-
-    -> Tests for functionality "Execute SixtyPical program"
-
-Rudimentary program.
-
-    | routine main {
-    |     ld a, 0
-    |     add a, 1
-    | }
-    = a: 1
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Program accesses a memory location.
-
-    | byte lives
-    | 
-    | routine main {
-    |     ld a, 0
-    |     st a, lives
-    |     ld x, lives
-    |     add x, 1
-    |     st x, lives
-    | }
-    = a: 0
-    = c: 0
-    = lives: 1
-    = n: 0
-    = v: 0
-    = x: 1
-    = y: 0
-    = z: 0
-
-Program accesses a memory location with initial value.
-
-    | byte lives : 3
-    | 
-    | routine main {
-    |     ld a, lives
-    | }
-    = a: 3
-    = c: 0
-    = lives: 3
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Add honours carry.
-
-    | routine main {
-    |     ld a, 255
-    |     st on, c
-    |     add a, 0
-    |   }
-    = a: 0
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 1
-
-    | routine main {
-    |     ld a, $ff
-    |     st off, c
-    |     add a, 1
-    |   }
-    = a: 0
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 1
-
-Subtract honours carry.
-
-    | routine main {
-    |     ld a, 0
-    |     st on, c
-    |     sub a, 0
-    |   }
-    = a: 255
-    = c: 1
-    = n: 1
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-    | routine main {
-    |     ld a, 0
-    |     st off, c
-    |     sub a, 1
-    | }
-    = a: 255
-    = c: 1
-    = n: 1
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Inc and dec do not honour carry, but do set n and z.
-
-    | routine main {
-    |     ld x, 254
-    |     st on, c
-    |     inc x
-    | }
-    = a: 0
-    = c: 1
-    = n: 1
-    = v: 0
-    = x: 255
-    = y: 0
-    = z: 0
-
-    | routine main {
-    |     ld y, 1
-    |     st on, c
-    |     dec y
-    | }
-    = a: 0
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 1
-
-Compare affects, but does not use, carry.
-
-    | routine main {
-    |     ld a, 1
-    |     st on, c
-    |     cmp a, 1
-    | }
-    = a: 1
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 1
-
-    | routine main {
-    |     ld a, 1
-    |     st off, c
-    |     cmp a, 5
-    | }
-    = a: 1
-    = c: 1
-    = n: 1
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-AND.
-
-    | routine main {
-    |     ld a, 15
-    |     and a, 18
-    |   }
-    = a: 2
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-OR.
-
-    | routine main {
-    |     ld a, 34
-    |     or a, 18
-    |   }
-    = a: 50
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-XOR.
-
-    | routine main {
-    |     ld a, 34
-    |     xor a, 18
-    |   }
-    = a: 48
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Shift left.
-
-    | routine main {
-    |     ld a, 129
-    |     st off, c
-    |     shl a
-    |   }
-    = a: 2
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-    | routine main {
-    |     ld a, 0
-    |     st on, c
-    |     shl a
-    |   }
-    = a: 1
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Shift right.
-
-    | routine main {
-    |     ld a, 129
-    |     st off, c
-    |     shr a
-    |   }
-    = a: 64
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-    | routine main {
-    |     ld a, 0
-    |     st on, c
-    |     shr a
-    |   }
-    = a: 128
-    = c: 0
-    = n: 1
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Call routine.
-
-    | routine up {
-    |     inc x
-    |     inc y
-    | }
-    | routine main {
-    |     ld x, 0
-    |     ld y, 1
-    |     call up
-    |     call up
-    | }
-    = a: 0
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 2
-    = y: 3
-    = z: 0
-
-If.
-
-    | routine main {
-    |     ld x, 40
-    |     cmp x, 40
-    |     if z {
-    |         ld a, 1
-    |     } else {
-    |         ld a, 8
-    |     }
-    |     ld x, 2
-    |   }
-    = a: 1
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 2
-    = y: 0
-    = z: 0
-
-    | routine main {
-    |     ld x, 39
-    |     cmp x, 40
-    |     if z {
-    |         ld a, 1
-    |     } else {
-    |         ld a, 8
-    |     }
-    |     ld x, 2
-    |   }
-    = a: 8
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 2
-    = y: 0
-    = z: 0
-
-If without else.
-
-    | routine main {
-    |     ld x, 39
-    |     cmp x, 40
-    |     if z {
-    |         ld a, 1
-    |     }
-    |     ld x, 2
-    |   }
-    = a: 0
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 2
-    = y: 0
-    = z: 0
-
-`not` inverts the sense of the test.
-
-    | routine main {
-    |     ld x, 40
-    |     cmp x, 40
-    |     if not z {
-    |         ld a, 1
-    |     } else {
-    |         ld a, 8
-    |     }
-    |     ld x, 2
-    |   }
-    = a: 8
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 2
-    = y: 0
-    = z: 0
-
-    | routine main {
-    |     ld x, 39
-    |     cmp x, 40
-    |     if not z {
-    |         ld a, 1
-    |     }
-    |     ld x, 2
-    |   }
-    = a: 1
-    = c: 1
-    = n: 0
-    = v: 0
-    = x: 2
-    = y: 0
-    = z: 0
-
-Repeat loop.
-
-    | routine main {
-    |     ld x, 0
-    |     ld y, 15
-    |     repeat {
-    |         inc x
-    |         inc y
-    |         cmp x, 10
-    |     } until z
-    | }
-    = a: 0
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 10
-    = y: 25
-    = z: 1
-
-Copy instruction.  Note that the state of a, z, and n are not defined
-after copy executes.
-
-    | routine main {
-    |     ld x, 5
-    |     copy x, y
-    | }
-    = a: 0
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 5
-    = y: 5
-    = z: 0
-
-Copy word to word.
-
-    | word foo : 2000
-    | word bar
-    | 
-    | routine main {
-    |     copy foo, bar
-    | }
-    = a: 0
-    = bar: 2000
-    = c: 0
-    = foo: 2000
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Copy literal word to word.
-
-    | word bar
-    | 
-    | routine main {
-    |     copy word 2000, bar
-    | }
-    = a: 0
-    = bar: 2000
-    = c: 0
-    = n: 0
-    = v: 0
-    = x: 0
-    = y: 0
-    = z: 0
-
-Indirect call.
-
-    | vector foo outputs x trashes z, n
-    | 
-    | routine bar outputs x trashes z, n {
-    |     ld x, 200
-    | }
-    | 
-    | routine main inputs bar outputs x, foo trashes a, z, n {
-    |     copy bar, foo
-    |     call foo
-    | }
-    = a: 0
-    = c: 0
-    = n: 1
-    = v: 0
-    = x: 200
-    = y: 0
-    = z: 0
-
-goto.
-
-    | routine bar outputs x trashes z, n {
-    |     ld x, 200
-    | }
-    | 
-    | routine main outputs x trashes a, z, n {
-    |     ld y, 200
-    |     goto bar
-    | }
-    = a: 0
-    = c: 0
-    = n: 1
-    = v: 0
-    = x: 200
-    = y: 200
-    = z: 0