def test_drop(self):
m = forth.Machine()
ret = m.eval('1 DROP')
assert ret == ' ok'
assert not m.data_stack
m = forth.Machine()
ret = m.eval('DROP')
assert ret == ' ? stack underflow'
def test_tuck(self):
m = forth.Machine()
ret = m.eval('1 2 TUCK')
assert ret == ' ok'
assert m.data_stack == [2, 1, 2]
m = forth.Machine()
ret = m.eval('1 TUCK')
assert ret == ' ? stack underflow'
def test_rot(self):
m = forth.Machine()
ret = m.eval('1 2 3 ROT')
assert ret == ' ok'
assert m.data_stack == [2, 3, 1]
m = forth.Machine()
ret = m.eval('1 2 ROT')
assert ret == ' ? stack underflow'
def test_over(self):
m = forth.Machine()
ret = m.eval('1 2 OVER')
assert ret == ' ok'
assert m.data_stack == [1, 2, 1]
m = forth.Machine()
ret = m.eval('1 OVER')
assert ret == ' ? stack underflow'
def test_dup(self):
m = forth.Machine()
ret = m.eval('9 DUP')
assert ret == ' ok'
assert m.data_stack == [9, 9]
m = forth.Machine()
ret = m.eval('DUP')
assert ret == ' ? stack underflow'
def test_two_operand_underflow(self):
for oper in ['+', '-', '*', '/', 'MOD', '/MOD', 'SWAP']:
m = forth.Machine()
ret = m.eval('1 ' + oper)
assert ret == ' ? stack underflow'
assert not m.data_stack
def test_bad_compile(self):
m = forth.Machine()
ret = m.eval(': STAR NO-SUCH-WORD')
assert 'undefined word' in ret
assert 'NO-SUCH-WORD' in ret
assert m.mode is forth.IMMEDIATE_MODE
def test_multi_loop(self):
m = forth.Machine()
ret = m.eval(': CR 10 EMIT ;\n'
': STAR 42 EMIT ;\n'
': STARS 0 DO STAR LOOP ;\n'
': STAR-LINES 0 DO 5 STARS CR LOOP ;\n'
'2 STAR-LINES')
assert ret == '*****\n*****\n ok'
m = forth.Machine()
ret = m.eval(': CR 10 EMIT ;\n'
': STAR-LINES 0 DO 5 0 DO 42 EMIT LOOP CR LOOP ;\n'
'2 STAR-LINES')
assert ret == '*****\n*****\n ok'
def test_interpret(self):
m = forth.Machine()
ret = m.interpret([('NUMBER', 42), ('NUMBER', 30),
('CALL', m.words['.'])])
assert ret == '30 '
assert m.data_stack == [42]
def test_quit(self):
m = forth.Machine()
ret = m.eval('4 QUIT 5')
assert ret == ''
assert 4 in m.data_stack
assert 5 not in m.data_stack
def test_plus_loop(self):
m = forth.Machine()
assert 'missing DO' in m.eval(': OOPS +LOOP ;')
assert 'underflow' in m.eval(': OOPS 2 0 DO 42 EMIT +LOOP ; OOPS')
ret = m.eval(': JUMP-TWO DO 42 EMIT 2 +LOOP ; 4 0 JUMP-TWO')
assert ret == '** ok'
def test_wrong_loop_close(self):
m = forth.Machine()
ret = m.eval(': BLAH')
m.return_stack.append('OOPSIE')
ret = m.eval('LOOP')
assert 'unclosed OOPSIE' in ret
def test_printstack(self):
m = forth.Machine()
ret = m.eval('42 1 2 3 .S')
assert m.data_stack == [42, 1, 2, 3]
# Kind of a fragile test, as it relies on the implementation of .S
# always including repr(self.data_stack), which it might not do in
# future. Nonetheless, it's currently sufficiently correct.
assert repr(m.data_stack) in ret
def forth_repl():
print('Type "BYE" or input an end of file (Ctrl+D) to quit.')
m = forth.Machine()
cmd = raw_input(PROMPT)
while cmd.upper() != 'BYE':
print(m.eval(cmd))
cmd = raw_input(PROMPT)
def test_twin_operators(self):
m = forth.Machine()
ret = m.eval('10 7 2DUP')
assert ret == ' ok'
assert m.data_stack == [10, 7, 10, 7]
m = forth.Machine()
ret = m.eval('1 2 3 4 2SWAP')
assert ret == ' ok'
assert m.data_stack == [3, 4, 1, 2]
m = forth.Machine()
ret = m.eval('1 2 3 4 2OVER')
assert ret == ' ok'
assert m.data_stack == [1, 2, 3, 4, 1, 2]
def test_if_else_on_stack(self):
m = forth.Machine()
ret = m.eval(': TEST IF ELSE')
assert 'compiled' in ret
assert 'IF' in m.return_stack
assert 'ELSE' in m.return_stack
assert 'IF' in m.data_stack
assert 'ELSE' in m.data_stack
def test_multi_eval(self):
m = forth.Machine()
ret = m.eval('12 34')
assert ret == ' ok'
assert m.data_stack == [12, 34]
ret = m.eval('+')
assert ret == ' ok'
assert m.data_stack == [46]
def test_comparisons(self):
m = forth.Machine()
ret = m.eval('''10 7
2DUP > .
2DUP >= .
2DUP < .
2DUP <= .
2DUP == .
2DUP != .''')
assert ret == '-1 -1 0 0 0 -1 ok'
def test_empty_if(self):
m = forth.Machine()
ret = m.eval(': TEST IF ELSE THEN ; 1 TEST')
assert ret == ' ok'
assert 'TEST' in m.words
assert not m.data_stack
assert not m.return_stack
ret = m.eval(': TEST IF 42 EMIT THEN ; 1 TEST 0 TEST')
assert ret == '* ok'
def test_if(self):
m = forth.Machine()
ret = m.eval(': TEST IF 42 ELSE 33 THEN . ;')
assert ret == ' ok'
assert 'TEST' in m.words
assert not m.data_stack
assert not m.return_stack
assert m.eval('1 TEST 0 TEST') == '42 33 ok'
assert 'stack underflow' in m.eval('TEST')
def test_error_clears_stack(self):
m = forth.Machine()
ret = m.eval('42')
assert ret == ' ok'
assert m.data_stack == [42]
ret = m.eval('NO-SUCH-WORD')
assert 'undefined word' in ret
assert not m.data_stack
def test_simple_math(self):
for oper, expected in {
'+': 24,
'-': 16,
'*': 80,
'/': 5,
'MOD': 0
}.iteritems():
m = forth.Machine()
ret = m.eval('20 4 ' + oper)
assert ret == ' ok'
assert expected in m.data_stack
def test_complete_compile(self):
m = forth.Machine()
ret = m.eval(': STAR 42 EMIT ;')
assert 'ok' in ret
assert 'STAR' in m.words
assert m.data_stack == []
assert m.mode is forth.IMMEDIATE_MODE
ret = m.eval('STAR')
assert ret == '* ok'
assert m.data_stack == []
def test_begin_until(self):
m = forth.Machine()
assert 'compile-only' in m.eval('BEGIN')
assert 'compile-only' in m.eval('UNTIL')
assert 'missing BEGIN' in m.eval(': TEST UNTIL')
assert 'unclosed DO' in m.eval(': TEST DO UNTIL')
ret = m.eval(''': TEST 0
BEGIN
DUP .
1 +
DUP
4 > UNTIL
; TEST''')
assert ret == '0 1 2 3 4 ok'
def test_leave(self):
m = forth.Machine()
assert 'compile-only' in m.eval('LEAVE')
assert '? not looping' in m.eval(': TEST LEAVE ; TEST')
ret = m.eval(''': TEST
10 5
2 0 DO
DUP
7 > IF
LEAVE
THEN
.
LOOP ;
TEST''')
assert ret == '5 ok'
def test_return_stack_fuckery(self):
m = forth.Machine()
ret = m.eval('1 2 3 >R SWAP R> . . .')
assert ret == '3 1 2 ok'
assert not m.data_stack
assert m.eval('2 >R R@ R> . .') == '2 2 ok'
assert not m.return_stack
assert 'return stack underflow' in m.eval('R>')
assert m.eval(': TEST 5 0 DO I . LOOP ; TEST') == '0 1 2 3 4 ok'
assert m.eval(': TEST 5 0 DO R> . 5 >R LOOP ; TEST') == '0 ok'
ret = m.eval(
': TEST 12 10 DO 22 20 DO 42 EMIT J . I . LOOP LOOP ; TEST')
assert ret == '*10 20 *10 21 *11 20 *11 21 ok'
def test_begin_while_repeat(self):
m = forth.Machine()
assert 'compile-only' in m.eval('BEGIN')
assert 'compile-only' in m.eval('WHILE')
assert 'compile-only' in m.eval('REPEAT')
assert 'missing BEGIN' in m.eval(': TEST WHILE')
assert 'missing WHILE' in m.eval(': TEST REPEAT')
assert 'unclosed DO' in m.eval(': TEST DO WHILE')
assert 'unclosed DO' in m.eval(': TEST DO REPEAT')
ret = m.eval(''': TEST 0
BEGIN
DUP
4 < WHILE
DUP .
1 +
REPEAT
; TEST''')
assert ret == '0 1 2 3 ok'
def test_two_part_compile(self):
m = forth.Machine()
ret = m.eval(': STAR')
ret = m.eval('42 EMIT')
assert ret == ' compiled'
assert ':' in m.data_stack
assert m.return_stack == [':']
assert m.mode is forth.COMPILE_MODE
assert 'STAR' not in m.words
ret = m.eval(';')
assert ret == ' ok'
assert m.data_stack == []
assert not m.return_stack
assert m.mode is forth.IMMEDIATE_MODE
assert 'STAR' in m.words
ret = m.eval('STAR STAR')
assert ret == '** ok'
assert m.data_stack == []
def test_swap(self):
m = forth.Machine()
ret = m.eval('5 12 SWAP')
assert ret == ' ok'
assert m.data_stack == [12, 5]
def test_divmod(self):
m = forth.Machine()
ret = m.eval('17 3 /MOD')
assert ret == ' ok'
assert m.data_stack == [2, 5]