def get_var_name(ins, allow_empty=False):
""" Get variable name from token stream. """
name = ''
d = skip_white_read(ins).upper()
if not d:
pass
elif d not in string.ascii_uppercase:
# variable name must start with a letter
ins.seek(-len(d), 1)
else:
while d and d in name_chars:
name += d
d = ins.read(1).upper()
if d in '$%!#':
name += d
else:
ins.seek(-len(d), 1)
if not name and not allow_empty:
raise error.RunError(error.STX)
# append type specifier
name = vartypes.complete_name(name)
# only the first 40 chars are relevant in GW-BASIC, rest is discarded
if len(name) > 41:
name = name[:40] + name[-1]
return name
def get_var_name(ins, allow_empty=False):
""" Get variable name from token stream. """
name = ''
d = skip_white_read(ins).upper()
if not d:
pass
elif d not in string.ascii_uppercase:
# variable name must start with a letter
ins.seek(-len(d), 1)
else:
while d and d in name_chars:
name += d
d = ins.read(1).upper()
if d in '$%!#':
name += d
else:
ins.seek(-len(d), 1)
if not name and not allow_empty:
raise error.RunError(error.STX)
# append type specifier
name = vartypes.complete_name(name)
# only the first 40 chars are relevant in GW-BASIC, rest is discarded
if len(name) > 41:
name = name[:40]+name[-1]
return name
def dim_array(name, dimensions):
""" Allocate array space for an array of given dimensioned size. Raise errors if duplicate name or illegal index value. """
if state.basic_state.array_base == None:
state.basic_state.array_base = 0
name = vartypes.complete_name(name)
if name in state.basic_state.arrays:
# duplicate definition
raise error.RunError(10)
for d in dimensions:
if d < 0:
# illegal function call
raise error.RunError(5)
elif d < state.basic_state.array_base:
# subscript out of range
raise error.RunError(9)
size = array_len(dimensions)
try:
state.basic_state.arrays[name] = [ dimensions, bytearray(size*var_size_bytes(name)), 0 ]
except OverflowError:
# out of memory
raise error.RunError(7)
except MemoryError:
# out of memory
raise error.RunError(7)
# update memory model
# first two bytes: chars of name or 0 if name is one byte long
name_ptr = state.basic_state.array_current
record_len = 1 + max(3, len(name)) + 3 + 2*len(dimensions)
array_ptr = name_ptr + record_len
state.basic_state.array_current += record_len + array_size_bytes(name)
state.basic_state.array_memory[name] = (name_ptr, array_ptr)
def set_var(name, value):
""" Assign a value to a variable. """
name = vartypes.complete_name(name)
type_char = name[-1]
# check if garbage needs collecting before allocating mem
size = (max(3, len(name)) + 1 + byte_size[type_char])
if type_char == '$':
unpacked = vartypes.pass_string_unpack(value)
size += len(unpacked)
if fre() <= size:
# TODO: GARBTEST difference is because string literal is currently stored in string space, whereas GW stores it in code space.
collect_garbage()
if fre() <= size:
raise error.RunError(7)
# assign variables
if type_char == '$':
# every assignment to string leads to new pointer being allocated
# TODO: string literals in programs have the var ptr point to program space.
state.basic_state.variables[name] = state.basic_state.strings.store(bytearray(unpacked[:]))
else:
# make a copy of the value in case we want to use POKE on it - we would change both values otherwise
# NOTE: this is an in-place copy - crucial for FOR!
try:
state.basic_state.variables[name][:] = vartypes.pass_type_keep(name[-1], value)[1][:]
except KeyError:
state.basic_state.variables[name] = vartypes.pass_type_keep(name[-1], value)[1][:]
# update memory model
# first two bytes: chars of name or 0 if name is one byte long
if name not in state.basic_state.var_memory:
name_ptr = state.basic_state.var_current
var_ptr = name_ptr + max(3, len(name)) + 1 # byte_size first_letter second_letter_or_nul remaining_length_or_nul
state.basic_state.var_current += max(3, len(name)) + 1 + byte_size[name[-1]]
state.basic_state.var_memory[name] = (name_ptr, var_ptr)
def dim_array(name, dimensions):
""" Allocate array space for an array of given dimensioned size. Raise errors if duplicate name or illegal index value. """
if state.basic_state.array_base is None:
state.basic_state.array_base = 0
name = vartypes.complete_name(name)
if name in state.basic_state.arrays:
raise error.RunError(error.DUPLICATE_DEFINITION)
for d in dimensions:
if d < 0:
raise error.RunError(error.IFC)
elif d < state.basic_state.array_base:
raise error.RunError(error.SUBSCRIPT_OUT_OF_RANGE)
size = array_len(dimensions)
# update memory model
# first two bytes: chars of name or 0 if name is one byte long
name_ptr = state.basic_state.array_current
record_len = 1 + max(3, len(name)) + 3 + 2*len(dimensions)
array_ptr = name_ptr + record_len
array_bytes = size*var_size_bytes(name)
check_free_memory(record_len + array_bytes, error.OUT_OF_MEMORY)
state.basic_state.array_current += record_len + array_bytes
state.basic_state.array_memory[name] = (name_ptr, array_ptr)
try:
state.basic_state.arrays[name] = [ dimensions, bytearray(array_bytes), 0 ]
except OverflowError:
# out of memory
raise error.RunError(error.OUT_OF_MEMORY)
except MemoryError:
# out of memory
raise error.RunError(error.OUT_OF_MEMORY)
def set_scalar(name, value=None):
""" Assign a value to a variable. """
name = vartypes.complete_name(name)
type_char = name[-1]
if value is not None:
value = vartypes.pass_type(type_char, value)
# update memory model
# check if garbage needs collecting before allocating memory
if name not in state.basic_state.var_memory:
# don't add string length, string already stored
size = (max(3, len(name)) + 1 + vartypes.byte_size[type_char])
check_free_memory(size, error.OUT_OF_MEMORY)
# first two bytes: chars of name or 0 if name is one byte long
name_ptr = state.basic_state.var_current
# byte_size first_letter second_letter_or_nul remaining_length_or_nul
var_ptr = name_ptr + max(3, len(name)) + 1
state.basic_state.var_current += max(3, len(name)) + 1 + vartypes.byte_size[name[-1]]
state.basic_state.var_memory[name] = (name_ptr, var_ptr)
# don't change the value if just checking allocation
if value is None:
if name in state.basic_state.variables:
return
else:
value = vartypes.null(type_char)
# copy buffers
try:
# in-place copy is crucial for FOR
state.basic_state.variables[name][:] = value[1][:]
except KeyError:
# copy into new buffer if not existing
state.basic_state.variables[name] = value[1][:]
def get_scalar(name):
""" Retrieve the value of a scalar variable. """
name = vartypes.complete_name(name)
try:
return (name[-1], state.basic_state.variables[name])
except KeyError:
return vartypes.null(name[-1])
def dim_array(name, dimensions):
""" Allocate array space for an array of given dimensioned size. Raise errors if duplicate name or illegal index value. """
if state.basic_state.array_base is None:
state.basic_state.array_base = 0
name = vartypes.complete_name(name)
if name in state.basic_state.arrays:
raise error.RunError(error.DUPLICATE_DEFINITION)
for d in dimensions:
if d < 0:
raise error.RunError(error.IFC)
elif d < state.basic_state.array_base:
raise error.RunError(error.SUBSCRIPT_OUT_OF_RANGE)
size = array_len(dimensions)
# update memory model
# first two bytes: chars of name or 0 if name is one byte long
name_ptr = state.basic_state.array_current
record_len = 1 + max(3, len(name)) + 3 + 2*len(dimensions)
array_ptr = name_ptr + record_len
array_bytes = size*var_size_bytes(name)
check_free_memory(record_len + array_bytes, error.OUT_OF_MEMORY)
state.basic_state.array_current += record_len + array_bytes
state.basic_state.array_memory[name] = (name_ptr, array_ptr)
try:
state.basic_state.arrays[name] = [ dimensions, bytearray(array_bytes), 0 ]
except OverflowError:
# out of memory
raise error.RunError(error.OUT_OF_MEMORY)
except MemoryError:
# out of memory
raise error.RunError(error.OUT_OF_MEMORY)
def get_scalar(name):
""" Retrieve the value of a scalar variable. """
name = vartypes.complete_name(name)
try:
return (name[-1], state.basic_state.variables[name])
except KeyError:
return vartypes.null(name[-1])
def set_scalar(name, value=None):
""" Assign a value to a variable. """
name = vartypes.complete_name(name)
type_char = name[-1]
if value is not None:
value = vartypes.pass_type(type_char, value)
# update memory model
# check if garbage needs collecting before allocating memory
if name not in state.basic_state.var_memory:
# don't add string length, string already stored
size = (max(3, len(name)) + 1 + vartypes.byte_size[type_char])
check_free_memory(size, error.OUT_OF_MEMORY)
# first two bytes: chars of name or 0 if name is one byte long
name_ptr = state.basic_state.var_current
# byte_size first_letter second_letter_or_nul remaining_length_or_nul
var_ptr = name_ptr + max(3, len(name)) + 1
state.basic_state.var_current += max(3, len(name)) + 1 + vartypes.byte_size[name[-1]]
state.basic_state.var_memory[name] = (name_ptr, var_ptr)
# don't change the value if just checking allocation
if value is None:
if name in state.basic_state.variables:
return
else:
value = vartypes.null(type_char)
# copy buffers
try:
# in-place copy is crucial for FOR
state.basic_state.variables[name][:] = value[1][:]
except KeyError:
# copy into new buffer if not existing
state.basic_state.variables[name] = value[1][:]
def get_var(name):
""" Retrieve the value of a variable. """
name = vartypes.complete_name(name)
try:
if name[-1] == '$':
return get_string_copy_packed(state.basic_state.variables[name])
else:
return (name[-1], state.basic_state.variables[name])
except KeyError:
return vartypes.null[name[-1]]
def get_var(name):
""" Retrieve the value of a variable. """
name = vartypes.complete_name(name)
try:
if name[-1] == '$':
return get_string_copy_packed(state.basic_state.variables[name])
else:
return (name[-1], state.basic_state.variables[name])
except KeyError:
return vartypes.null[name[-1]]
def varptr(name, indices):
"""Get address of variable. """
name = vartypes.complete_name(name)
if indices == []:
try:
_, var_ptr = state.basic_state.var_memory[name]
return var_ptr
except KeyError:
return -1
else:
try:
dimensions, _, _ = state.basic_state.arrays[name]
_, array_ptr = state.basic_state.array_memory[name]
# arrays are kept at the end of the var list
return state.basic_state.var_current + array_ptr + var.var_size_bytes(name) * var.index_array(indices, dimensions)
except KeyError:
return -1
def varptr(name, indices):
"""Get address of variable. """
name = vartypes.complete_name(name)
if indices == []:
try:
_, var_ptr = state.basic_state.var_memory[name]
return var_ptr
except KeyError:
return -1
else:
try:
dimensions, _, _ = state.basic_state.arrays[name]
_, array_ptr = state.basic_state.array_memory[name]
# arrays are kept at the end of the var list
return state.basic_state.var_current + array_ptr + var.var_size_bytes(
name) * var.index_array(indices, dimensions)
except KeyError:
return -1
def set_var(name, value):
""" Assign a value to a variable. """
name = vartypes.complete_name(name)
type_char = name[-1]
# check if garbage needs collecting before allocating mem
size = (max(3, len(name)) + 1 + byte_size[type_char])
if type_char == '$':
unpacked = vartypes.pass_string_unpack(value)
size += len(unpacked)
if fre() <= size:
# TODO: GARBTEST difference is because string literal is currently stored in string space, whereas GW stores it in code space.
collect_garbage()
if fre() <= size:
raise error.RunError(error.OUT_OF_MEMORY)
# assign variables
if type_char == '$':
# every assignment to string leads to new pointer being allocated
# TODO: string literals in programs have the var ptr point to program space.
state.basic_state.variables[name] = state.basic_state.strings.store(
bytearray(unpacked[:]))
else:
# make a copy of the value in case we want to use POKE on it - we would change both values otherwise
# NOTE: this is an in-place copy - crucial for FOR!
try:
state.basic_state.variables[name][:] = vartypes.pass_type_keep(
name[-1], value)[1][:]
except KeyError:
state.basic_state.variables[name] = vartypes.pass_type_keep(
name[-1], value)[1][:]
# update memory model
# first two bytes: chars of name or 0 if name is one byte long
if name not in state.basic_state.var_memory:
name_ptr = state.basic_state.var_current
var_ptr = name_ptr + max(
3, len(name)
) + 1 # byte_size first_letter second_letter_or_nul remaining_length_or_nul
state.basic_state.var_current += max(
3, len(name)) + 1 + byte_size[name[-1]]
state.basic_state.var_memory[name] = (name_ptr, var_ptr)
