hy/hy/models.py

364 lines
10 KiB
Python

# Copyright 2019 the authors.
# This file is part of Hy, which is free software licensed under the Expat
# license. See the LICENSE.
from __future__ import unicode_literals
from contextlib import contextmanager
from math import isnan, isinf
from hy import _initialize_env_var
from hy._compat import PY3, str_type, bytes_type, long_type, string_types
from hy.errors import HyWrapperError
from fractions import Fraction
from clint.textui import colored
PRETTY = True
_hy_colored_ast_objects = _initialize_env_var('HY_COLORED_AST_OBJECTS', False)
@contextmanager
def pretty(pretty=True):
"""
Context manager to temporarily enable
or disable pretty-printing of Hy model reprs.
"""
global PRETTY
old, PRETTY = PRETTY, pretty
try:
yield
finally:
PRETTY = old
class HyObject(object):
"""
Generic Hy Object model. This is helpful to inject things into all the
Hy lexing Objects at once.
The position properties (`start_line`, `end_line`, `start_column`,
`end_column`) are each 1-based and inclusive. For example, a symbol
`abc` starting at the first column would have `start_column` 1 and
`end_column` 3.
"""
__properties__ = ["module", "start_line", "end_line", "start_column",
"end_column"]
def replace(self, other, recursive=False):
if isinstance(other, HyObject):
for attr in self.__properties__:
if not hasattr(self, attr) and hasattr(other, attr):
setattr(self, attr, getattr(other, attr))
else:
raise TypeError("Can't replace a non Hy object '{}' with a Hy object '{}'".format(repr(other), repr(self)))
return self
def __repr__(self):
return "%s(%s)" % (self.__class__.__name__, super(HyObject, self).__repr__())
_wrappers = {}
def wrap_value(x):
"""Wrap `x` into the corresponding Hy type.
This allows replace_hy_obj to convert a non Hy object to a Hy object.
This also allows a macro to return an unquoted expression transparently.
"""
new = _wrappers.get(type(x), lambda y: y)(x)
if not isinstance(new, HyObject):
raise HyWrapperError("Don't know how to wrap {!r}: {!r}".format(type(x), x))
if isinstance(x, HyObject):
new = new.replace(x, recursive=False)
if not hasattr(new, "start_column"):
new.start_column = 0
if not hasattr(new, "start_line"):
new.start_line = 0
return new
def replace_hy_obj(obj, other):
return wrap_value(obj).replace(other)
def repr_indent(obj):
return repr(obj).replace("\n", "\n ")
class HyString(HyObject, str_type):
"""
Generic Hy String object. Helpful to store string literals from Hy
scripts. It's either a ``str`` or a ``unicode``, depending on the
Python version.
"""
def __new__(cls, s=None, is_format=False, brackets=None):
value = super(HyString, cls).__new__(cls, s)
value.is_format = bool(is_format)
value.brackets = brackets
return value
_wrappers[str_type] = HyString
class HyBytes(HyObject, bytes_type):
"""
Generic Hy Bytes object. It's either a ``bytes`` or a ``str``, depending
on the Python version.
"""
pass
_wrappers[bytes_type] = HyBytes
class HySymbol(HyObject, str_type):
"""
Hy Symbol. Basically a string.
"""
def __new__(cls, s=None):
return super(HySymbol, cls).__new__(cls, s)
_wrappers[bool] = lambda x: HySymbol("True") if x else HySymbol("False")
_wrappers[type(None)] = lambda foo: HySymbol("None")
class HyKeyword(HyObject):
"""Generic Hy Keyword object."""
__slots__ = ['name']
def __init__(self, value):
self.name = value
def __repr__(self):
return "%s(%r)" % (self.__class__.__name__, self.name)
def __str__(self):
return ":%s" % self.name
def __hash__(self):
return hash(self.name)
def __eq__(self, other):
if not isinstance(other, HyKeyword):
return NotImplemented
return self.name == other.name
def __ne__(self, other):
if not isinstance(other, HyKeyword):
return NotImplemented
return self.name != other.name
def __bool__(self):
return bool(self.name)
_sentinel = object()
def __call__(self, data, default=_sentinel):
try:
return data[self]
except KeyError:
if default is HyKeyword._sentinel:
raise
return default
def strip_digit_separators(number):
# Don't strip a _ or , if it's the first character, as _42 and
# ,42 aren't valid numbers
return (number[0] + number[1:].replace("_", "").replace(",", "")
if isinstance(number, string_types) and len(number) > 1
else number)
class HyInteger(HyObject, long_type):
"""
Internal representation of a Hy Integer. May raise a ValueError as if
int(foo) was called, given HyInteger(foo). On python 2.x long will
be used instead
"""
def __new__(cls, number, *args, **kwargs):
if isinstance(number, string_types):
number = strip_digit_separators(number)
bases = {"0x": 16, "0o": 8, "0b": 2}
for leader, base in bases.items():
if number.startswith(leader):
# We've got a string, known leader, set base.
number = long_type(number, base=base)
break
else:
# We've got a string, no known leader; base 10.
number = long_type(number, base=10)
else:
# We've got a non-string; convert straight.
number = long_type(number)
return super(HyInteger, cls).__new__(cls, number)
_wrappers[int] = HyInteger
if not PY3: # do not add long on python3
_wrappers[long_type] = HyInteger
def check_inf_nan_cap(arg, value):
if isinstance(arg, string_types):
if isinf(value) and "i" in arg.lower() and "Inf" not in arg:
raise ValueError('Inf must be capitalized as "Inf"')
if isnan(value) and "NaN" not in arg:
raise ValueError('NaN must be capitalized as "NaN"')
class HyFloat(HyObject, float):
"""
Internal representation of a Hy Float. May raise a ValueError as if
float(foo) was called, given HyFloat(foo).
"""
def __new__(cls, num, *args, **kwargs):
value = super(HyFloat, cls).__new__(cls, strip_digit_separators(num))
check_inf_nan_cap(num, value)
return value
_wrappers[float] = HyFloat
class HyComplex(HyObject, complex):
"""
Internal representation of a Hy Complex. May raise a ValueError as if
complex(foo) was called, given HyComplex(foo).
"""
def __new__(cls, real, imag=0, *args, **kwargs):
if isinstance(real, string_types):
value = super(HyComplex, cls).__new__(
cls, strip_digit_separators(real)
)
p1, _, p2 = real.lstrip("+-").replace("-", "+").partition("+")
check_inf_nan_cap(p1, value.imag if "j" in p1 else value.real)
if p2:
check_inf_nan_cap(p2, value.imag)
return value
return super(HyComplex, cls).__new__(cls, real, imag)
_wrappers[complex] = HyComplex
class HySequence(HyObject, list):
"""
An abstract type for sequence-like models to inherit from.
"""
def replace(self, other, recursive=True):
if recursive:
for x in self:
replace_hy_obj(x, other)
HyObject.replace(self, other)
return self
def __add__(self, other):
return self.__class__(super(HySequence, self).__add__(other))
def __getslice__(self, start, end):
return self.__class__(super(HySequence, self).__getslice__(start, end))
def __getitem__(self, item):
ret = super(HySequence, self).__getitem__(item)
if isinstance(item, slice):
return self.__class__(ret)
return ret
color = None
def __repr__(self):
return str(self) if PRETTY else super(HySequence, self).__repr__()
def __str__(self):
global _hy_colored_ast_objects
with pretty():
c = self.color if _hy_colored_ast_objects else str
if self:
return ("{}{}\n {}{}").format(
c(self.__class__.__name__),
c("(["),
(c(",") + "\n ").join([repr_indent(e) for e in self]),
c("])"))
else:
return '' + c(self.__class__.__name__ + "()")
class HyList(HySequence):
color = staticmethod(colored.cyan)
def recwrap(f):
return lambda l: f(wrap_value(x) for x in l)
_wrappers[HyList] = recwrap(HyList)
_wrappers[list] = recwrap(HyList)
_wrappers[tuple] = recwrap(HyList)
class HyDict(HySequence):
"""
HyDict (just a representation of a dict)
"""
color = staticmethod(colored.green)
def __str__(self):
global _hy_colored_ast_objects
with pretty():
g = self.color if _hy_colored_ast_objects else str
if self:
pairs = []
for k, v in zip(self[::2],self[1::2]):
k, v = repr_indent(k), repr_indent(v)
pairs.append(
("{0}{c}\n {1}\n "
if '\n' in k+v
else "{0}{c} {1}").format(k, v, c=g(',')))
if len(self) % 2 == 1:
pairs.append("{} {}\n".format(
repr_indent(self[-1]), g("# odd")))
return "{}\n {}{}".format(
g("HyDict(["), ("{c}\n ".format(c=g(',')).join(pairs)), g("])"))
else:
return '' + g("HyDict()")
def keys(self):
return self[0::2]
def values(self):
return self[1::2]
def items(self):
return list(zip(self.keys(), self.values()))
_wrappers[HyDict] = recwrap(HyDict)
_wrappers[dict] = lambda d: HyDict(wrap_value(x) for x in sum(d.items(), ()))
class HyExpression(HySequence):
"""
Hy S-Expression. Basically just a list.
"""
color = staticmethod(colored.yellow)
_wrappers[HyExpression] = recwrap(HyExpression)
_wrappers[Fraction] = lambda e: HyExpression(
[HySymbol("fraction"), wrap_value(e.numerator), wrap_value(e.denominator)])
class HySet(HySequence):
"""
Hy set (just a representation of a set)
"""
color = staticmethod(colored.red)
_wrappers[HySet] = recwrap(HySet)
_wrappers[set] = recwrap(HySet)