hy/hy/compiler.py

2213 lines
82 KiB
Python
Executable File

# -*- encoding: utf-8 -*-
# Copyright 2020 the authors.
# This file is part of Hy, which is free software licensed under the Expat
# license. See the LICENSE.
from hy.models import (HyObject, HyExpression, HyKeyword, HyInteger, HyComplex,
HyString, HyBytes, HySymbol, HyFloat, HyList, HySet,
HyDict, HySequence, wrap_value)
from hy.model_patterns import (FORM, SYM, KEYWORD, STR, sym, brackets, whole,
notpexpr, dolike, pexpr, times, Tag, tag, unpack)
from funcparserlib.parser import some, many, oneplus, maybe, NoParseError
from hy.errors import (HyCompileError, HyTypeError, HyLanguageError,
HySyntaxError, HyEvalError, HyInternalError)
from hy.lex import mangle, unmangle, hy_parse, parse_one_thing, LexException
from hy._compat import (PY36, PY38, reraise)
from hy.macros import require, load_macros, macroexpand, tag_macroexpand
import hy.core
import re
import textwrap
import pkgutil
import traceback
import itertools
import importlib
import inspect
import types
import ast
import sys
import copy
import builtins
import __future__
from collections import defaultdict
from functools import reduce
Inf = float('inf')
hy_ast_compile_flags = (__future__.CO_FUTURE_DIVISION |
__future__.CO_FUTURE_PRINT_FUNCTION)
def ast_compile(ast, filename, mode):
"""Compile AST.
Parameters
----------
ast : instance of `ast.AST`
filename : str
Filename used for run-time error messages
mode: str
`compile` mode parameter
Returns
-------
out : instance of `types.CodeType`
"""
return compile(ast, filename, mode, hy_ast_compile_flags)
def calling_module(n=1):
"""Get the module calling, if available.
As a fallback, this will import a module using the calling frame's
globals value of `__name__`.
Parameters
----------
n: int, optional
The number of levels up the stack from this function call.
The default is one level up.
Returns
-------
out: types.ModuleType
The module at stack level `n + 1` or `None`.
"""
frame_up = inspect.stack(0)[n + 1][0]
module = inspect.getmodule(frame_up)
if module is None:
# This works for modules like `__main__`
module_name = frame_up.f_globals.get('__name__', None)
if module_name:
try:
module = importlib.import_module(module_name)
except ImportError:
pass
return module
def ast_str(x, piecewise=False):
if piecewise:
return ".".join(ast_str(s) if s else "" for s in x.split("."))
return mangle(x)
_special_form_compilers = {}
_model_compilers = {}
_decoratables = (ast.FunctionDef, ast.ClassDef, ast.AsyncFunctionDef)
# _bad_roots are fake special operators, which are used internally
# by other special forms (e.g., `except` in `try`) but can't be
# used to construct special forms themselves.
_bad_roots = tuple(ast_str(x) for x in (
"unquote", "unquote-splice", "unpack-mapping", "except"))
def special(names, pattern):
"""Declare special operators. The decorated method and the given pattern
is assigned to _special_form_compilers for each of the listed names."""
pattern = whole(pattern)
def dec(fn):
for name in names if isinstance(names, list) else [names]:
if isinstance(name, tuple):
condition, name = name
if not condition:
continue
_special_form_compilers[ast_str(name)] = (fn, pattern)
return fn
return dec
def builds_model(*model_types):
"Assign the decorated method to _model_compilers for the given types."
def _dec(fn):
for t in model_types:
_model_compilers[t] = fn
return fn
return _dec
# Provide asty.Foo(x, ...) as shorthand for
# ast.Foo(..., lineno=x.start_line, col_offset=x.start_column) or
# ast.Foo(..., lineno=x.lineno, col_offset=x.col_offset)
class Asty(object):
def __getattr__(self, name):
setattr(Asty, name, staticmethod(lambda x, **kwargs: getattr(ast, name)(
lineno=getattr(
x, 'start_line', getattr(x, 'lineno', None)),
col_offset=getattr(
x, 'start_column', getattr(x, 'col_offset', None)),
**kwargs)))
return getattr(Asty, name)
asty = Asty()
class Result(object):
"""
Smart representation of the result of a hy->AST compilation
This object tries to reconcile the hy world, where everything can be used
as an expression, with the Python world, where statements and expressions
need to coexist.
To do so, we represent a compiler result as a list of statements `stmts`,
terminated by an expression context `expr`. The expression context is used
when the compiler needs to use the result as an expression.
Results are chained by addition: adding two results together returns a
Result representing the succession of the two Results' statements, with
the second Result's expression context.
We make sure that a non-empty expression context does not get clobbered by
adding more results, by checking accesses to the expression context. We
assume that the context has been used, or deliberately ignored, if it has
been accessed.
The Result object is interoperable with python AST objects: when an AST
object gets added to a Result object, it gets converted on-the-fly.
"""
__slots__ = ("imports", "stmts", "temp_variables",
"_expr", "__used_expr")
def __init__(self, *args, **kwargs):
if args:
# emulate kw-only args for future bits.
raise TypeError("Yo: Hacker: don't pass me real args, dingus")
self.imports = defaultdict(set)
self.stmts = []
self.temp_variables = []
self._expr = None
self.__used_expr = False
# XXX: Make sure we only have AST where we should.
for kwarg in kwargs:
if kwarg not in ["imports", "stmts", "expr", "temp_variables"]:
raise TypeError(
"%s() got an unexpected keyword argument '%s'" % (
self.__class__.__name__, kwarg))
setattr(self, kwarg, kwargs[kwarg])
@property
def expr(self):
self.__used_expr = True
return self._expr
@expr.setter
def expr(self, value):
self.__used_expr = False
self._expr = value
@property
def lineno(self):
if self._expr is not None:
return self._expr.lineno
if self.stmts:
return self.stmts[-1].lineno
return None
@property
def col_offset(self):
if self._expr is not None:
return self._expr.col_offset
if self.stmts:
return self.stmts[-1].col_offset
return None
def add_imports(self, mod, imports):
"""Autoimport `imports` from `mod`"""
self.imports[mod].update(imports)
def is_expr(self):
"""Check whether I am a pure expression"""
return self._expr and not (self.imports or self.stmts)
@property
def force_expr(self):
"""Force the expression context of the Result.
If there is no expression context, we return a "None" expression.
"""
if self.expr:
return self.expr
return ast.Name(
id=ast_str("None"),
ctx=ast.Load(),
lineno=self.stmts[-1].lineno if self.stmts else 0,
col_offset=self.stmts[-1].col_offset if self.stmts else 0)
def expr_as_stmt(self):
"""Convert the Result's expression context to a statement
This is useful when we want to use the stored expression in a
statement context (for instance in a code branch).
We drop ast.Names if they are appended to statements, as they
can't have any side effect. "Bare" names still get converted to
statements.
If there is no expression context, return an empty result.
"""
if self.expr and not (isinstance(self.expr, ast.Name) and self.stmts):
return Result() + asty.Expr(self.expr, value=self.expr)
return Result()
def rename(self, new_name):
"""Rename the Result's temporary variables to a `new_name`.
We know how to handle ast.Names and ast.FunctionDefs.
"""
new_name = ast_str(new_name)
for var in self.temp_variables:
if isinstance(var, ast.Name):
var.id = new_name
var.arg = new_name
elif isinstance(var, (ast.FunctionDef, ast.AsyncFunctionDef)):
var.name = new_name
else:
raise TypeError("Don't know how to rename a %s!" % (
var.__class__.__name__))
self.temp_variables = []
def __add__(self, other):
# If we add an ast statement, convert it first
if isinstance(other, ast.stmt):
return self + Result(stmts=[other])
# If we add an ast expression, clobber the expression context
if isinstance(other, ast.expr):
return self + Result(expr=other)
if isinstance(other, ast.excepthandler):
return self + Result(stmts=[other])
if not isinstance(other, Result):
raise TypeError("Can't add %r with non-compiler result %r" % (
self, other))
# Check for expression context clobbering
if self.expr and not self.__used_expr:
traceback.print_stack()
print("Bad boy clobbered expr %s with %s" % (
ast.dump(self.expr),
ast.dump(other.expr)))
# Fairly obvious addition
result = Result()
result.imports = other.imports
result.stmts = self.stmts + other.stmts
result.expr = other.expr
result.temp_variables = other.temp_variables
return result
def __str__(self):
return (
"Result(imports=[%s], stmts=[%s], expr=%s)"
% (
", ".join(ast.dump(x) for x in self.imports),
", ".join(ast.dump(x) for x in self.stmts),
ast.dump(self.expr) if self.expr else None
))
def is_unpack(kind, x):
return (isinstance(x, HyExpression)
and len(x) > 0
and isinstance(x[0], HySymbol)
and x[0] == "unpack-" + kind)
def make_hy_model(outer, x, rest):
return outer(
[HySymbol(a) if type(a) is str else
a[0] if type(a) is list else a
for a in x] +
(rest or []))
def mkexpr(*items, **kwargs):
return make_hy_model(HyExpression, items, kwargs.get('rest'))
def mklist(*items, **kwargs):
return make_hy_model(HyList, items, kwargs.get('rest'))
# Parse an annotation setting.
OPTIONAL_ANNOTATION = maybe(pexpr(sym("annotate*") + FORM) >> (lambda x: x[0]))
def is_annotate_expression(model):
return (isinstance(model, HyExpression) and model and isinstance(model[0], HySymbol)
and model[0] == HySymbol("annotate*"))
class HyASTCompiler(object):
"""A Hy-to-Python AST compiler"""
def __init__(self, module, filename=None, source=None):
"""
Parameters
----------
module: str or types.ModuleType
Module name or object in which the Hy tree is evaluated.
filename: str, optional
The name of the file for the source to be compiled.
This is optional information for informative error messages and
debugging.
source: str, optional
The source for the file, if any, being compiled. This is optional
information for informative error messages and debugging.
"""
self.anon_var_count = 0
self.imports = defaultdict(set)
self.temp_if = None
if not inspect.ismodule(module):
self.module = importlib.import_module(module)
else:
self.module = module
self.module_name = self.module.__name__
self.filename = filename
self.source = source
# Hy expects these to be present, so we prep the module for Hy
# compilation.
self.module.__dict__.setdefault('__macros__', {})
self.module.__dict__.setdefault('__tags__', {})
self.can_use_stdlib = not self.module_name.startswith("hy.core")
self._stdlib = {}
# Everything in core needs to be explicit (except for
# the core macros, which are built with the core functions).
if self.can_use_stdlib:
# Load stdlib macros into the module namespace.
load_macros(self.module)
# Populate _stdlib.
for stdlib_module in hy.core.STDLIB:
mod = importlib.import_module(stdlib_module)
for e in map(ast_str, getattr(mod, 'EXPORTS', [])):
self._stdlib[e] = stdlib_module
def get_anon_var(self):
self.anon_var_count += 1
return "_hy_anon_var_%s" % self.anon_var_count
def update_imports(self, result):
"""Retrieve the imports from the result object"""
for mod in result.imports:
self.imports[mod].update(result.imports[mod])
def imports_as_stmts(self, expr):
"""Convert the Result's imports to statements"""
ret = Result()
for module, names in self.imports.items():
if None in names:
ret += self.compile(mkexpr('import', module).replace(expr))
names = sorted(name for name in names if name)
if names:
ret += self.compile(mkexpr('import',
mklist(module, mklist(*names))))
self.imports = defaultdict(set)
return ret.stmts
def compile_atom(self, atom):
# Compilation methods may mutate the atom, so copy it first.
atom = copy.copy(atom)
return Result() + _model_compilers[type(atom)](self, atom)
def compile(self, tree):
if tree is None:
return Result()
try:
ret = self.compile_atom(tree)
self.update_imports(ret)
return ret
except HyCompileError:
# compile calls compile, so we're going to have multiple raise
# nested; so let's re-raise this exception, let's not wrap it in
# another HyCompileError!
raise
except HyLanguageError as e:
# These are expected errors that should be passed to the user.
reraise(type(e), e, sys.exc_info()[2])
except Exception as e:
# These are unexpected errors that will--hopefully--never be seen
# by the user.
f_exc = traceback.format_exc()
exc_msg = "Internal Compiler Bug 😱\n{}".format(f_exc)
reraise(HyCompileError, HyCompileError(exc_msg), sys.exc_info()[2])
def _syntax_error(self, expr, message):
return HySyntaxError(message, expr, self.filename, self.source)
def _compile_collect(self, exprs, with_kwargs=False, dict_display=False):
"""Collect the expression contexts from a list of compiled expression.
This returns a list of the expression contexts, and the sum of the
Result objects passed as arguments.
"""
compiled_exprs = []
ret = Result()
keywords = []
exprs_iter = iter(exprs)
for expr in exprs_iter:
if is_unpack("mapping", expr):
ret += self.compile(expr[1])
if dict_display:
compiled_exprs.append(None)
compiled_exprs.append(ret.force_expr)
elif with_kwargs:
keywords.append(asty.keyword(
expr, arg=None, value=ret.force_expr))
elif with_kwargs and isinstance(expr, HyKeyword):
try:
value = next(exprs_iter)
except StopIteration:
raise self._syntax_error(expr,
"Keyword argument {kw} needs a value.".format(kw=expr))
if not expr:
raise self._syntax_error(expr,
"Can't call a function with the empty keyword")
compiled_value = self.compile(value)
ret += compiled_value
arg = str(expr)[1:]
keywords.append(asty.keyword(
expr, arg=ast_str(arg), value=compiled_value.force_expr))
else:
ret += self.compile(expr)
compiled_exprs.append(ret.force_expr)
return compiled_exprs, ret, keywords
def _compile_branch(self, exprs):
"""Make a branch out of an iterable of Result objects
This generates a Result from the given sequence of Results, forcing each
expression context as a statement before the next result is used.
We keep the expression context of the last argument for the returned Result
"""
ret = Result()
for x in map(self.compile, exprs[:-1]):
ret += x
ret += x.expr_as_stmt()
if exprs:
ret += self.compile(exprs[-1])
return ret
def _storeize(self, expr, name, func=None):
"""Return a new `name` object with an ast.Store() context"""
if not func:
func = ast.Store
if isinstance(name, Result):
if not name.is_expr():
raise self._syntax_error(expr,
"Can't assign or delete a non-expression")
name = name.expr
if isinstance(name, (ast.Tuple, ast.List)):
typ = type(name)
new_elts = []
for x in name.elts:
new_elts.append(self._storeize(expr, x, func))
new_name = typ(elts=new_elts)
elif isinstance(name, ast.Name):
new_name = ast.Name(id=name.id)
elif isinstance(name, ast.Subscript):
new_name = ast.Subscript(value=name.value, slice=name.slice)
elif isinstance(name, ast.Attribute):
new_name = ast.Attribute(value=name.value, attr=name.attr)
elif isinstance(name, ast.Starred):
new_name = ast.Starred(
value=self._storeize(expr, name.value, func))
else:
raise self._syntax_error(expr,
"Can't assign or delete a %s" % type(expr).__name__)
new_name.ctx = func()
ast.copy_location(new_name, name)
return new_name
def _render_quoted_form(self, form, level):
"""
Render a quoted form as a new HyExpression.
`level` is the level of quasiquoting of the current form. We can
unquote if level is 0.
Returns a three-tuple (`imports`, `expression`, `splice`).
The `splice` return value is used to mark `unquote-splice`d forms.
We need to distinguish them as want to concatenate them instead of
just nesting them.
"""
op = None
if isinstance(form, HyExpression) and form and (
isinstance(form[0], HySymbol)):
op = unmangle(ast_str(form[0]))
if level == 0 and op in ("unquote", "unquote-splice"):
if len(form) != 2:
raise HyTypeError("`%s' needs 1 argument, got %s" % op, len(form) - 1,
self.filename, form, self.source)
return set(), form[1], op == "unquote-splice"
elif op == "quasiquote":
level += 1
elif op in ("unquote", "unquote-splice"):
level -= 1
name = form.__class__.__name__
imports = set([name])
body = [form]
if isinstance(form, HySequence):
contents = []
for x in form:
f_imps, f_contents, splice = self._render_quoted_form(x, level)
imports.update(f_imps)
if splice:
contents.append(HyExpression([
HySymbol("list"),
HyExpression([HySymbol("or"), f_contents, HyList()])]))
else:
contents.append(HyList([f_contents]))
if form:
# If there are arguments, they can be spliced
# so we build a sum...
body = [HyExpression([HySymbol("+"), HyList()] + contents)]
else:
body = [HyList()]
elif isinstance(form, HySymbol):
body = [HyString(form)]
elif isinstance(form, HyKeyword):
body = [HyString(form.name)]
elif isinstance(form, HyString):
if form.is_format:
# Ensure that this f-string isn't evaluated right now.
body = [
copy.copy(form),
HyKeyword("is_format"),
form.is_format,
]
body[0].is_format = False
if form.brackets is not None:
body.extend([HyKeyword("brackets"), form.brackets])
ret = HyExpression([HySymbol(name)] + body).replace(form)
return imports, ret, False
@special(["quote", "quasiquote"], [FORM])
def compile_quote(self, expr, root, arg):
level = Inf if root == "quote" else 0 # Only quasiquotes can unquote
imports, stmts, _ = self._render_quoted_form(arg, level)
ret = self.compile(stmts)
ret.add_imports("hy", imports)
return ret
@special("unpack-iterable", [FORM])
def compile_unpack_iterable(self, expr, root, arg):
ret = self.compile(arg)
ret += asty.Starred(expr, value=ret.force_expr, ctx=ast.Load())
return ret
@special("do", [many(FORM)])
def compile_do(self, expr, root, body):
return self._compile_branch(body)
@special("raise", [maybe(FORM), maybe(sym(":from") + FORM)])
def compile_raise_expression(self, expr, root, exc, cause):
ret = Result()
if exc is not None:
exc = self.compile(exc)
ret += exc
exc = exc.force_expr
if cause is not None:
cause = self.compile(cause)
ret += cause
cause = cause.force_expr
return ret + asty.Raise(
expr, type=ret.expr, exc=exc,
inst=None, tback=None, cause=cause)
@special("try",
[many(notpexpr("except", "else", "finally")),
many(pexpr(sym("except"),
brackets() | brackets(FORM) | brackets(SYM, FORM),
many(FORM))),
maybe(dolike("else")),
maybe(dolike("finally"))])
def compile_try_expression(self, expr, root, body, catchers, orelse, finalbody):
body = self._compile_branch(body)
return_var = asty.Name(
expr, id=ast_str(self.get_anon_var()), ctx=ast.Store())
handler_results = Result()
handlers = []
for catcher in catchers:
handler_results += self._compile_catch_expression(
catcher, return_var, *catcher)
handlers.append(handler_results.stmts.pop())
if orelse is None:
orelse = []
else:
orelse = self._compile_branch(orelse)
orelse += asty.Assign(expr, targets=[return_var],
value=orelse.force_expr)
orelse += orelse.expr_as_stmt()
orelse = orelse.stmts
if finalbody is None:
finalbody = []
else:
finalbody = self._compile_branch(finalbody)
finalbody += finalbody.expr_as_stmt()
finalbody = finalbody.stmts
# Using (else) without (except) is verboten!
if orelse and not handlers:
raise self._syntax_error(expr,
"`try' cannot have `else' without `except'")
# Likewise a bare (try) or (try BODY).
if not (handlers or finalbody):
raise self._syntax_error(expr,
"`try' must have an `except' or `finally' clause")
returnable = Result(
expr=asty.Name(expr, id=return_var.id, ctx=ast.Load()),
temp_variables=[return_var])
body += body.expr_as_stmt() if orelse else asty.Assign(
expr, targets=[return_var], value=body.force_expr)
body = body.stmts or [asty.Pass(expr)]
x = asty.Try(
expr,
body=body,
handlers=handlers,
orelse=orelse,
finalbody=finalbody)
return handler_results + x + returnable
def _compile_catch_expression(self, expr, var, exceptions, body):
# exceptions catch should be either:
# [[list of exceptions]]
# or
# [variable [list of exceptions]]
# or
# [variable exception]
# or
# [exception]
# or
# []
name = None
if len(exceptions) == 2:
name = ast_str(exceptions[0])
exceptions_list = exceptions[-1] if exceptions else HyList()
if isinstance(exceptions_list, HyList):
if len(exceptions_list):
# [FooBar BarFoo] → catch Foobar and BarFoo exceptions
elts, types, _ = self._compile_collect(exceptions_list)
types += asty.Tuple(exceptions_list, elts=elts, ctx=ast.Load())
else:
# [] → all exceptions caught
types = Result()
else:
types = self.compile(exceptions_list)
body = self._compile_branch(body)
body += asty.Assign(expr, targets=[var], value=body.force_expr)
body += body.expr_as_stmt()
return types + asty.ExceptHandler(
expr, type=types.expr, name=name,
body=body.stmts or [asty.Pass(expr)])
@special("if*", [FORM, FORM, maybe(FORM)])
def compile_if(self, expr, _, cond, body, orel_expr):
cond = self.compile(cond)
body = self.compile(body)
nested = root = False
orel = Result()
if orel_expr is not None:
if isinstance(orel_expr, HyExpression) and isinstance(orel_expr[0],
HySymbol) and orel_expr[0] == 'if*':
# Nested ifs: don't waste temporaries
root = self.temp_if is None
nested = True
self.temp_if = self.temp_if or self.get_anon_var()
orel = self.compile(orel_expr)
if not cond.stmts and isinstance(cond.force_expr, ast.Name):
name = cond.force_expr.id
branch = None
if name == 'True':
branch = body
elif name in ('False', 'None'):
branch = orel
if branch is not None:
if self.temp_if and branch.stmts:
name = asty.Name(expr,
id=ast_str(self.temp_if),
ctx=ast.Store())
branch += asty.Assign(expr,
targets=[name],
value=body.force_expr)
return branch
# We want to hoist the statements from the condition
ret = cond
if body.stmts or orel.stmts:
# We have statements in our bodies
# Get a temporary variable for the result storage
var = self.temp_if or self.get_anon_var()
name = asty.Name(expr,
id=ast_str(var),
ctx=ast.Store())
# Store the result of the body
body += asty.Assign(expr,
targets=[name],
value=body.force_expr)
# and of the else clause
if not nested or not orel.stmts or (not root and
var != self.temp_if):
orel += asty.Assign(expr,
targets=[name],
value=orel.force_expr)
# Then build the if
ret += asty.If(expr,
test=ret.force_expr,
body=body.stmts,
orelse=orel.stmts)
# And make our expression context our temp variable
expr_name = asty.Name(expr, id=ast_str(var), ctx=ast.Load())
ret += Result(expr=expr_name, temp_variables=[expr_name, name])
else:
# Just make that an if expression
ret += asty.IfExp(expr,
test=ret.force_expr,
body=body.force_expr,
orelse=orel.force_expr)
if root:
self.temp_if = None
return ret
@special(["break", "continue"], [])
def compile_break_or_continue_expression(self, expr, root):
return (asty.Break if root == "break" else asty.Continue)(expr)
@special("assert", [FORM, maybe(FORM)])
def compile_assert_expression(self, expr, root, test, msg):
if msg is None or type(msg) is HySymbol:
ret = self.compile(test)
return ret + asty.Assert(
expr,
test=ret.force_expr,
msg=(None if msg is None else self.compile(msg).force_expr))
# The `msg` part may involve statements, which we only
# want to be executed if the assertion fails. Rewrite the
# form to set `msg` to a variable.
msg_var = self.get_anon_var()
return self.compile(mkexpr(
'if*', mkexpr('and', '__debug__', mkexpr('not', [test])),
mkexpr('do',
mkexpr('setv', msg_var, [msg]),
mkexpr('assert', 'False', msg_var))).replace(expr))
@special(["global", "nonlocal"], [oneplus(SYM)])
def compile_global_or_nonlocal(self, expr, root, syms):
node = asty.Global if root == "global" else asty.Nonlocal
return node(expr, names=list(map(ast_str, syms)))
@special("yield", [maybe(FORM)])
def compile_yield_expression(self, expr, root, arg):
ret = Result()
if arg is not None:
ret += self.compile(arg)
return ret + asty.Yield(expr, value=ret.force_expr)
@special(["yield-from", "await"], [FORM])
def compile_yield_from_or_await_expression(self, expr, root, arg):
ret = Result() + self.compile(arg)
node = asty.YieldFrom if root == "yield-from" else asty.Await
return ret + node(expr, value=ret.force_expr)
@special("get", [FORM, oneplus(FORM)])
def compile_index_expression(self, expr, name, obj, indices):
indices, ret, _ = self._compile_collect(indices)
ret += self.compile(obj)
for ix in indices:
ret += asty.Subscript(
expr,
value=ret.force_expr,
slice=ast.Index(value=ix),
ctx=ast.Load())
return ret
@special(".", [FORM, many(SYM | brackets(FORM))])
def compile_attribute_access(self, expr, name, invocant, keys):
ret = self.compile(invocant)
for attr in keys:
if isinstance(attr, HySymbol):
ret += asty.Attribute(attr,
value=ret.force_expr,
attr=ast_str(attr),
ctx=ast.Load())
else: # attr is a HyList
compiled_attr = self.compile(attr[0])
ret = compiled_attr + ret + asty.Subscript(
attr,
value=ret.force_expr,
slice=ast.Index(value=compiled_attr.force_expr),
ctx=ast.Load())
return ret
@special("del", [many(FORM)])
def compile_del_expression(self, expr, name, args):
if not args:
return asty.Pass(expr)
del_targets = []
ret = Result()
for target in args:
compiled_target = self.compile(target)
ret += compiled_target
del_targets.append(self._storeize(target, compiled_target,
ast.Del))
return ret + asty.Delete(expr, targets=del_targets)
@special("cut", [FORM, maybe(FORM), maybe(FORM), maybe(FORM)])
def compile_cut_expression(self, expr, name, obj, lower, upper, step):
ret = [Result()]
def c(e):
ret[0] += self.compile(e)
return ret[0].force_expr
s = asty.Subscript(
expr,
value=c(obj),
slice=ast.Slice(lower=c(lower), upper=c(upper), step=c(step)),
ctx=ast.Load())
return ret[0] + s
@special("with-decorator", [oneplus(FORM)])
def compile_decorate_expression(self, expr, name, args):
decs, fn = args[:-1], self.compile(args[-1])
if not fn.stmts or not isinstance(fn.stmts[-1], _decoratables):
raise self._syntax_error(args[-1],
"Decorated a non-function")
decs, ret, _ = self._compile_collect(decs)
fn.stmts[-1].decorator_list = decs + fn.stmts[-1].decorator_list
return ret + fn
@special(["with*", "with/a*"],
[brackets(FORM, maybe(FORM)), many(FORM)])
def compile_with_expression(self, expr, root, args, body):
thing, ctx = (None, args[0]) if args[1] is None else args
if thing is not None:
thing = self._storeize(thing, self.compile(thing))
ctx = self.compile(ctx)
body = self._compile_branch(body)
# Store the result of the body in a tempvar
var = self.get_anon_var()
name = asty.Name(expr, id=ast_str(var), ctx=ast.Store())
body += asty.Assign(expr, targets=[name], value=body.force_expr)
# Initialize the tempvar to None in case the `with` exits
# early with an exception.
initial_assign = asty.Assign(
expr, targets=[name], value=asty.Name(
expr, id=ast_str("None"), ctx=ast.Load()))
node = asty.With if root == "with*" else asty.AsyncWith
the_with = node(expr,
context_expr=ctx.force_expr,
optional_vars=thing,
body=body.stmts,
items=[ast.withitem(context_expr=ctx.force_expr,
optional_vars=thing)])
ret = Result(stmts=[initial_assign]) + ctx + the_with
# And make our expression context our temp variable
expr_name = asty.Name(expr, id=ast_str(var), ctx=ast.Load())
ret += Result(expr=expr_name)
# We don't give the Result any temp_vars because we don't want
# Result.rename to touch `name`. Otherwise, initial_assign will
# clobber any preexisting value of the renamed-to variable.
return ret
@special(",", [many(FORM)])
def compile_tuple(self, expr, root, args):
elts, ret, _ = self._compile_collect(args)
return ret + asty.Tuple(expr, elts=elts, ctx=ast.Load())
_loopers = many(
tag('setv', sym(":setv") + FORM + FORM) |
tag('if', sym(":if") + FORM) |
tag('do', sym(":do") + FORM) |
tag('afor', sym(":async") + FORM + FORM) |
tag('for', FORM + FORM))
@special(["for"], [brackets(_loopers),
many(notpexpr("else")) + maybe(dolike("else"))])
@special(["lfor", "sfor", "gfor"], [_loopers, FORM])
@special(["dfor"], [_loopers, brackets(FORM, FORM)])
def compile_comprehension(self, expr, root, parts, final):
node_class = {
"for": asty.For,
"lfor": asty.ListComp,
"dfor": asty.DictComp,
"sfor": asty.SetComp,
"gfor": asty.GeneratorExp}[root]
is_for = root == "for"
orel = []
if is_for:
# Get the `else`.
body, else_expr = final
if else_expr is not None:
orel.append(self._compile_branch(else_expr))
orel[0] += orel[0].expr_as_stmt()
else:
# Get the final value (and for dictionary
# comprehensions, the final key).
if node_class is asty.DictComp:
key, elt = map(self.compile, final)
else:
key = None
elt = self.compile(final)
# Compile the parts.
if is_for:
parts = parts[0]
if not parts:
return Result(expr=ast.parse({
asty.For: "None",
asty.ListComp: "[]",
asty.DictComp: "{}",
asty.SetComp: "{1}.__class__()",
asty.GeneratorExp: "(_ for _ in [])"}[node_class]).body[0].value)
parts = [
Tag(p.tag, self.compile(p.value) if p.tag in ["if", "do"] else [
self._storeize(p.value[0], self.compile(p.value[0])),
self.compile(p.value[1])])
for p in parts]
# Produce a result.
if (is_for or elt.stmts or (key is not None and key.stmts) or
any(p.tag == 'do' or (p.value[1].stmts if p.tag in ("for", "afor", "setv") else p.value.stmts)
for p in parts)):
# The desired comprehension can't be expressed as a
# real Python comprehension. We'll write it as a nested
# loop in a function instead.
def f(parts):
# This function is called recursively to construct
# the nested loop.
if not parts:
if is_for:
if body:
bd = self._compile_branch(body)
return bd + bd.expr_as_stmt()
return Result(stmts=[asty.Pass(expr)])
if node_class is asty.DictComp:
ret = key + elt
val = asty.Tuple(
key, ctx=ast.Load(),
elts=[key.force_expr, elt.force_expr])
else:
ret = elt
val = elt.force_expr
return ret + asty.Expr(
elt, value=asty.Yield(elt, value=val))
(tagname, v), parts = parts[0], parts[1:]
if tagname in ("for", "afor"):
orelse = orel and orel.pop().stmts
node = asty.AsyncFor if tagname == "afor" else asty.For
return v[1] + node(
v[1], target=v[0], iter=v[1].force_expr, body=f(parts).stmts,
orelse=orelse)
elif tagname == "setv":
return v[1] + asty.Assign(
v[1], targets=[v[0]], value=v[1].force_expr) + f(parts)
elif tagname == "if":
return v + asty.If(
v, test=v.force_expr, body=f(parts).stmts, orelse=[])
elif tagname == "do":
return v + v.expr_as_stmt() + f(parts)
else:
raise ValueError("can't happen")
if is_for:
return f(parts)
fname = self.get_anon_var()
# Define the generator function.
ret = Result() + asty.FunctionDef(
expr,
name=fname,
args=ast.arguments(
args=[], vararg=None, kwarg=None, posonlyargs=[],
kwonlyargs=[], kw_defaults=[], defaults=[]),
body=f(parts).stmts,
decorator_list=[])
# Immediately call the new function. Unless the user asked
# for a generator, wrap the call in `[].__class__(...)` or
# `{}.__class__(...)` or `{1}.__class__(...)` to get the
# right type. We don't want to just use e.g. `list(...)`
# because the name `list` might be rebound.
return ret + Result(expr=ast.parse(
"{}({}())".format(
{asty.ListComp: "[].__class__",
asty.DictComp: "{}.__class__",
asty.SetComp: "{1}.__class__",
asty.GeneratorExp: ""}[node_class],
fname)).body[0].value)
# We can produce a real comprehension.
generators = []
for tagname, v in parts:
if tagname in ("for", "afor"):
generators.append(ast.comprehension(
target=v[0], iter=v[1].expr, ifs=[],
is_async=int(tagname == "afor")))
elif tagname == "setv":
generators.append(ast.comprehension(
target=v[0],
iter=asty.Tuple(v[1], elts=[v[1].expr], ctx=ast.Load()),
ifs=[], is_async=0))
elif tagname == "if":
generators[-1].ifs.append(v.expr)
else:
raise ValueError("can't happen")
if node_class is asty.DictComp:
return asty.DictComp(expr, key=key.expr, value=elt.expr, generators=generators)
return node_class(expr, elt=elt.expr, generators=generators)
@special(["not", "~"], [FORM])
def compile_unary_operator(self, expr, root, arg):
ops = {"not": ast.Not,
"~": ast.Invert}
operand = self.compile(arg)
return operand + asty.UnaryOp(
expr, op=ops[root](), operand=operand.force_expr)
_symn = some(lambda x: isinstance(x, HySymbol) and "." not in x)
@special(["import", "require"], [many(
SYM |
brackets(SYM, sym(":as"), _symn) |
brackets(SYM, brackets(many(_symn + maybe(sym(":as") + _symn)))))])
def compile_import_or_require(self, expr, root, entries):
ret = Result()
for entry in entries:
assignments = "ALL"
prefix = ""
if isinstance(entry, HySymbol):
# e.g., (import foo)
module, prefix = entry, entry
elif isinstance(entry, HyList) and isinstance(entry[1], HySymbol):
# e.g., (import [foo :as bar])
module, prefix = entry
else:
# e.g., (import [foo [bar baz :as MyBaz bing]])
# or (import [foo [*]])
module, kids = entry
kids = kids[0]
if (HySymbol('*'), None) in kids:
if len(kids) != 1:
star = kids[kids.index((HySymbol('*'), None))][0]
raise self._syntax_error(star,
"* in an import name list must be on its own")
else:
assignments = [(k, v or k) for k, v in kids]
ast_module = ast_str(module, piecewise=True)
if root == "import":
module = ast_module.lstrip(".")
level = len(ast_module) - len(module)
if assignments == "ALL" and prefix == "":
node = asty.ImportFrom
names = [ast.alias(name="*", asname=None)]
elif assignments == "ALL":
node = asty.Import
prefix = ast_str(prefix, piecewise=True)
names = [ast.alias(
name=ast_module,
asname=prefix if prefix != module else None)]
else:
node = asty.ImportFrom
names = [
ast.alias(
name=ast_str(k),
asname=None if v == k else ast_str(v))
for k, v in assignments]
ret += node(
expr, module=module or None, names=names, level=level)
elif require(ast_module, self.module, assignments=assignments,
prefix=prefix):
# Actually calling `require` is necessary for macro expansions
# occurring during compilation.
self.imports['hy.macros'].update([None])
# The `require` we're creating in AST is the same as above, but used at
# run-time (e.g. when modules are loaded via bytecode).
ret += self.compile(HyExpression([
HySymbol('hy.macros.require'),
HyString(ast_module),
HySymbol('None'),
HyKeyword('assignments'),
(HyString("ALL") if assignments == "ALL" else
[[HyString(k), HyString(v)] for k, v in assignments]),
HyKeyword('prefix'),
HyString(prefix)]).replace(expr))
return ret
@special(["and", "or"], [many(FORM)])
def compile_logical_or_and_and_operator(self, expr, operator, args):
ops = {"and": (ast.And, "True"),
"or": (ast.Or, "None")}
opnode, default = ops[operator]
osym = expr[0]
if len(args) == 0:
return asty.Name(osym, id=default, ctx=ast.Load())
elif len(args) == 1:
return self.compile(args[0])
ret = Result()
values = list(map(self.compile, args))
if any(value.stmts for value in values):
# Compile it to an if...else sequence
var = self.get_anon_var()
name = asty.Name(osym, id=var, ctx=ast.Store())
expr_name = asty.Name(osym, id=var, ctx=ast.Load())
temp_variables = [name, expr_name]
def make_assign(value, node=None):
positioned_name = asty.Name(
node or osym, id=var, ctx=ast.Store())
temp_variables.append(positioned_name)
return asty.Assign(
node or osym, targets=[positioned_name], value=value)
current = root = []
for i, value in enumerate(values):
if value.stmts:
node = value.stmts[0]
current.extend(value.stmts)
else:
node = value.expr
current.append(make_assign(value.force_expr, value.force_expr))
if i == len(values)-1:
# Skip a redundant 'if'.
break
if operator == "and":
cond = expr_name
elif operator == "or":
cond = asty.UnaryOp(node, op=ast.Not(), operand=expr_name)
current.append(asty.If(node, test=cond, body=[], orelse=[]))
current = current[-1].body
ret = sum(root, ret)
ret += Result(expr=expr_name, temp_variables=temp_variables)
else:
ret += asty.BoolOp(osym,
op=opnode(),
values=[value.force_expr for value in values])
return ret
_c_ops = {"=": ast.Eq, "!=": ast.NotEq,
"<": ast.Lt, "<=": ast.LtE,
">": ast.Gt, ">=": ast.GtE,
"is": ast.Is, "is-not": ast.IsNot,
"in": ast.In, "not-in": ast.NotIn}
_c_ops = {ast_str(k): v for k, v in _c_ops.items()}
def _get_c_op(self, sym):
k = ast_str(sym)
if k not in self._c_ops:
raise self._syntax_error(sym,
"Illegal comparison operator: " + str(sym))
return self._c_ops[k]()
@special(["=", "is", "<", "<=", ">", ">="], [oneplus(FORM)])
@special(["!=", "is-not", "in", "not-in"], [times(2, Inf, FORM)])
def compile_compare_op_expression(self, expr, root, args):
if len(args) == 1:
return (self.compile(args[0]) +
asty.Name(expr, id="True", ctx=ast.Load()))
ops = [self._get_c_op(root) for _ in args[1:]]
exprs, ret, _ = self._compile_collect(args)
return ret + asty.Compare(
expr, left=exprs[0], ops=ops, comparators=exprs[1:])
@special("cmp", [FORM, many(SYM + FORM)])
def compile_chained_comparison(self, expr, root, arg1, args):
ret = self.compile(arg1)
arg1 = ret.force_expr
ops = [self._get_c_op(op) for op, _ in args]
args, ret2, _ = self._compile_collect(
[x for _, x in args])
return ret + ret2 + asty.Compare(expr,
left=arg1, ops=ops, comparators=args)
# The second element of each tuple below is an aggregation operator
# that's used for augmented assignment with three or more arguments.
m_ops = {"+": (ast.Add, "+"),
"/": (ast.Div, "*"),
"//": (ast.FloorDiv, "*"),
"*": (ast.Mult, "*"),
"-": (ast.Sub, "+"),
"%": (ast.Mod, None),
"**": (ast.Pow, "**"),
"<<": (ast.LShift, "+"),
">>": (ast.RShift, "+"),
"|": (ast.BitOr, "|"),
"^": (ast.BitXor, None),
"&": (ast.BitAnd, "&"),
"@": (ast.MatMult, "@")}
@special(["+", "*", "|"], [many(FORM)])
@special(["-", "/", "&", "@"], [oneplus(FORM)])
@special(["**", "//", "<<", ">>"], [times(2, Inf, FORM)])
@special(["%", "^"], [times(2, 2, FORM)])
def compile_maths_expression(self, expr, root, args):
if len(args) == 0:
# Return the identity element for this operator.
return asty.Num(expr, n=(
{"+": 0, "|": 0, "*": 1}[root]))
if len(args) == 1:
if root == "/":
# Compute the reciprocal of the argument.
args = [HyInteger(1).replace(expr), args[0]]
elif root in ("+", "-"):
# Apply unary plus or unary minus to the argument.
op = {"+": ast.UAdd, "-": ast.USub}[root]()
ret = self.compile(args[0])
return ret + asty.UnaryOp(expr, op=op, operand=ret.force_expr)
else:
# Return the argument unchanged.
return self.compile(args[0])
op = self.m_ops[root][0]
right_associative = root == "**"
ret = self.compile(args[-1 if right_associative else 0])
for child in args[-2 if right_associative else 1 ::
-1 if right_associative else 1]:
left_expr = ret.force_expr
ret += self.compile(child)
right_expr = ret.force_expr
if right_associative:
left_expr, right_expr = right_expr, left_expr
ret += asty.BinOp(expr, left=left_expr, op=op(), right=right_expr)
return ret
a_ops = {x + "=": v for x, v in m_ops.items()}
@special([x for x, (_, v) in a_ops.items() if v is not None], [FORM, oneplus(FORM)])
@special([x for x, (_, v) in a_ops.items() if v is None], [FORM, times(1, 1, FORM)])
def compile_augassign_expression(self, expr, root, target, values):
if len(values) > 1:
return self.compile(mkexpr(root, [target],
mkexpr(self.a_ops[root][1], rest=values)).replace(expr))
op = self.a_ops[root][0]
target = self._storeize(target, self.compile(target))
ret = self.compile(values[0])
return ret + asty.AugAssign(
expr, target=target, value=ret.force_expr, op=op())
@special("setv", [many(OPTIONAL_ANNOTATION + FORM + FORM)])
@special((PY38, "setx"), [times(1, 1, SYM + FORM)])
def compile_def_expression(self, expr, root, decls):
if not decls:
return asty.Name(expr, id='None', ctx=ast.Load())
result = Result()
is_assignment_expr = root == HySymbol("setx")
for decl in decls:
if is_assignment_expr:
ann = None
name, value = decl
else:
ann, name, value = decl
result += self._compile_assign(ann, name, value,
is_assignment_expr=is_assignment_expr)
return result
@special(["annotate*"], [FORM, FORM])
def compile_basic_annotation(self, expr, root, ann, target):
return self._compile_assign(ann, target, None)
def _compile_assign(self, ann, name, value, *, is_assignment_expr = False):
# Ensure that assignment expressions have a result and no annotation.
assert not is_assignment_expr or (value is not None and ann is None)
ld_name = self.compile(name)
annotate_only = value is None
if annotate_only:
result = Result()
else:
result = self.compile(value)
invalid_name = False
if ann is not None:
# An annotation / annotated assignment is more strict with the target expression.
invalid_name = not isinstance(ld_name.expr, (ast.Name, ast.Attribute, ast.Subscript))
else:
invalid_name = (str(name) in ("None", "True", "False")
or isinstance(ld_name.expr, ast.Call))
if invalid_name:
raise self._syntax_error(name, "illegal target for {}".format(
"annotation" if annotate_only else "assignment"))
if (result.temp_variables
and isinstance(name, HySymbol)
and '.' not in name):
result.rename(name)
if not is_assignment_expr:
# Throw away .expr to ensure that (setv ...) returns None.
result.expr = None
else:
st_name = self._storeize(name, ld_name)
if ann is not None:
ann_result = self.compile(ann)
result = ann_result + result
if is_assignment_expr:
node = asty.NamedExpr
elif ann is not None:
if not PY36:
raise self._syntax_error(name, "Variable annotations are not supported on "
"Python <=3.6")
node = lambda x, **kw: asty.AnnAssign(x, annotation=ann_result.force_expr,
simple=int(isinstance(name, HySymbol)),
**kw)
else:
node = asty.Assign
result += node(
name if hasattr(name, "start_line") else result,
value=result.force_expr if not annotate_only else None,
target=st_name, targets=[st_name])
return result
@special(["while"], [FORM, many(notpexpr("else")), maybe(dolike("else"))])
def compile_while_expression(self, expr, root, cond, body, else_expr):
cond_compiled = self.compile(cond)
body = self._compile_branch(body)
body += body.expr_as_stmt()
body_stmts = body.stmts or [asty.Pass(expr)]
if cond_compiled.stmts:
# We need to ensure the statements for the condition are
# executed on every iteration. Rewrite the loop to use a
# single anonymous variable as the condition, i.e.:
# anon_var = True
# while anon_var:
# condition stmts...
# anon_var = condition expr
# if anon_var:
# while loop body
cond_var = asty.Name(cond, id=self.get_anon_var(), ctx=ast.Load())
def make_not(operand):
return asty.UnaryOp(cond, op=ast.Not(), operand=operand)
body_stmts = cond_compiled.stmts + [
asty.Assign(cond, targets=[self._storeize(cond, cond_var)],
# Cast the condition to a bool in case it's mutable and
# changes its truth value, but use (not (not ...)) instead of
# `bool` in case `bool` has been redefined.
value=make_not(make_not(cond_compiled.force_expr))),
asty.If(cond, test=cond_var, body=body_stmts, orelse=[]),
]
cond_compiled = (Result()
+ asty.Assign(cond, targets=[self._storeize(cond, cond_var)],
value=asty.Name(cond, id="True", ctx=ast.Load()))
+ cond_var)
orel = Result()
if else_expr is not None:
orel = self._compile_branch(else_expr)
orel += orel.expr_as_stmt()
ret = cond_compiled + asty.While(
expr, test=cond_compiled.force_expr,
body=body_stmts,
orelse=orel.stmts)
return ret
NASYM = some(lambda x: isinstance(x, HySymbol) and x not in (
"&optional", "&rest", "&kwonly", "&kwargs"))
@special(["fn", "fn*", "fn/a"], [
# The starred version is for internal use (particularly, in the
# definition of `defn`). It ensures that a FunctionDef is
# produced rather than a Lambda.
OPTIONAL_ANNOTATION,
brackets(
many(OPTIONAL_ANNOTATION + NASYM),
maybe(sym("&optional") + many(OPTIONAL_ANNOTATION
+ (NASYM | brackets(SYM, FORM)))),
maybe(sym("&rest") + OPTIONAL_ANNOTATION + NASYM),
maybe(sym("&kwonly") + many(OPTIONAL_ANNOTATION
+ (NASYM | brackets(SYM, FORM)))),
maybe(sym("&kwargs") + OPTIONAL_ANNOTATION + NASYM)),
many(FORM)])
def compile_function_def(self, expr, root, returns, params, body):
force_functiondef = root in ("fn*", "fn/a")
node = asty.AsyncFunctionDef if root == "fn/a" else asty.FunctionDef
ret = Result()
# NOTE: Our evaluation order of return type annotations is
# different from Python: Python evalautes them after the argument
# annotations / defaults (as that's where they are in the source),
# but Hy evaluates them *first*, since here they come before the #
# argument list. Therefore, it would be more confusing for
# readability to evaluate them after like Python.
ret = Result()
returns_ann = None
if returns is not None:
returns_result = self.compile(returns)
ret += returns_result
mandatory, optional, rest, kwonly, kwargs = params
optional = optional or []
kwonly = kwonly or []
mandatory_ast, _, ret = self._compile_arguments_set(mandatory, False, ret)
optional_ast, optional_defaults, ret = self._compile_arguments_set(optional, True, ret)
kwonly_ast, kwonly_defaults, ret = self._compile_arguments_set(kwonly, False, ret)
rest_ast = kwargs_ast = None
if rest is not None:
[rest_ast], _, ret = self._compile_arguments_set([rest], False, ret)
if kwargs is not None:
[kwargs_ast], _, ret = self._compile_arguments_set([kwargs], False, ret)
args = ast.arguments(
args=mandatory_ast + optional_ast, defaults=optional_defaults,
vararg=rest_ast,
posonlyargs=[],
kwonlyargs=kwonly_ast, kw_defaults=kwonly_defaults,
kwarg=kwargs_ast)
body = self._compile_branch(body)
if not force_functiondef and not body.stmts and returns is None:
return ret + asty.Lambda(expr, args=args, body=body.force_expr)
if body.expr:
body += asty.Return(body.expr, value=body.expr)
name = self.get_anon_var()
ret += node(expr,
name=name,
args=args,
body=body.stmts or [asty.Pass(expr)],
decorator_list=[],
returns=returns_result.force_expr if returns is not None else None)
ast_name = asty.Name(expr, id=name, ctx=ast.Load())
ret += Result(expr=ast_name, temp_variables=[ast_name, ret.stmts[-1]])
return ret
def _compile_arguments_set(self, decls, implicit_default_none, ret):
args_ast = []
args_defaults = []
for ann, decl in decls:
default = None
# funcparserlib will check to make sure that the only times we
# ever have a HyList here are due to a default value.
if isinstance(decl, HyList):
sym, default = decl
else:
sym = decl
if implicit_default_none:
default = HySymbol('None').replace(sym)
if ann is not None:
ret += self.compile(ann)
ann_ast = ret.force_expr
else:
ann_ast = None
if default is not None:
ret += self.compile(default)
args_defaults.append(ret.force_expr)
else:
# Note that the only time any None should ever appear here
# is in kwargs, since the order of those with defaults vs
# those without isn't significant in the same way as
# positional args.
args_defaults.append(None)
args_ast.append(asty.arg(sym, arg=ast_str(sym), annotation=ann_ast))
return args_ast, args_defaults, ret
@special("return", [maybe(FORM)])
def compile_return(self, expr, root, arg):
ret = Result()
if arg is None:
return asty.Return(expr, value=None)
ret += self.compile(arg)
return ret + asty.Return(expr, value=ret.force_expr)
@special("defclass", [
SYM,
maybe(brackets(many(FORM)) + maybe(STR) + many(FORM))])
def compile_class_expression(self, expr, root, name, rest):
base_list, docstring, body = rest or ([[]], None, [])
bases_expr, bases, keywords = (
self._compile_collect(base_list[0], with_kwargs=True))
bodyr = Result()
if docstring is not None:
bodyr += self.compile(docstring).expr_as_stmt()
for e in body:
e = self.compile(self._rewire_init(
macroexpand(e, self.module, self)))
bodyr += e + e.expr_as_stmt()
return bases + asty.ClassDef(
expr,
decorator_list=[],
name=ast_str(name),
keywords=keywords,
starargs=None,
kwargs=None,
bases=bases_expr,
body=bodyr.stmts or [asty.Pass(expr)])
def _rewire_init(self, expr):
"Given a (setv …) form, append None to definitions of __init__."
if not (isinstance(expr, HyExpression)
and len(expr) > 1
and isinstance(expr[0], HySymbol)
and expr[0] == HySymbol("setv")):
return expr
new_args = []
decls = list(expr[1:])
while decls:
if is_annotate_expression(decls[0]):
# Handle annotations.
ann = decls.pop(0)
else:
ann = None
k, v = (decls.pop(0), decls.pop(0))
if ast_str(k) == "__init__" and isinstance(v, HyExpression):
v += HyExpression([HySymbol("None")])
if ann is not None:
new_args.append(ann)
new_args.extend((k, v))
return HyExpression([HySymbol("setv")] + new_args).replace(expr)
@special("dispatch-tag-macro", [STR, FORM])
def compile_dispatch_tag_macro(self, expr, root, tag, arg):
return self.compile(tag_macroexpand(
HyString(mangle(tag)).replace(tag),
arg,
self.module))
@special(["eval-and-compile", "eval-when-compile"], [many(FORM)])
def compile_eval_and_compile(self, expr, root, body):
new_expr = HyExpression([HySymbol("do").replace(expr[0])]).replace(expr)
try:
hy_eval(new_expr + body,
self.module.__dict__,
self.module,
filename=self.filename,
source=self.source)
except HyInternalError:
# Unexpected "meta" compilation errors need to be treated
# like normal (unexpected) compilation errors at this level
# (or the compilation level preceding this one).
raise
except Exception as e:
# These could be expected Hy language errors (e.g. syntax errors)
# or regular Python runtime errors that do not signify errors in
# the compilation *process* (although compilation did technically
# fail).
# We wrap these exceptions and pass them through.
reraise(HyEvalError,
HyEvalError(str(e),
self.filename,
body,
self.source),
sys.exc_info()[2])
return (self._compile_branch(body)
if ast_str(root) == "eval_and_compile"
else Result())
@special(["py", "pys"], [STR])
def compile_inline_python(self, expr, root, code):
exec_mode = root == HySymbol("pys")
try:
o = ast.parse(
textwrap.dedent(code) if exec_mode else code,
self.filename,
'exec' if exec_mode else 'eval').body
except (SyntaxError, ValueError if PY36 else TypeError) as e:
raise self._syntax_error(
expr,
"Python parse error in '{}': {}".format(root, e))
return Result(stmts=o) if exec_mode else o
@builds_model(HyExpression)
def compile_expression(self, expr, *, allow_annotation_expression=False):
# Perform macro expansions
expr = macroexpand(expr, self.module, self)
if not isinstance(expr, HyExpression):
# Go through compile again if the type changed.
return self.compile(expr)
if not expr:
raise self._syntax_error(expr,
"empty expressions are not allowed at top level")
args = list(expr)
root = args.pop(0)
func = None
if isinstance(root, HySymbol):
# First check if `root` is a special operator, unless it has an
# `unpack-iterable` in it, since Python's operators (`+`,
# etc.) can't unpack. An exception to this exception is that
# tuple literals (`,`) can unpack. Finally, we allow unpacking in
# `.` forms here so the user gets a better error message.
sroot = ast_str(root)
bad_root = sroot in _bad_roots or (sroot == ast_str("annotate*")
and not allow_annotation_expression)
if (sroot in _special_form_compilers or bad_root) and (
sroot in (mangle(","), mangle(".")) or
not any(is_unpack("iterable", x) for x in args)):
if bad_root:
raise self._syntax_error(expr,
"The special form '{}' is not allowed here".format(root))
# `sroot` is a special operator. Get the build method and
# pattern-match the arguments.
build_method, pattern = _special_form_compilers[sroot]
try:
parse_tree = pattern.parse(args)
except NoParseError as e:
raise self._syntax_error(
expr[min(e.state.pos + 1, len(expr) - 1)],
"parse error for special form '{}': {}".format(
root, e.msg.replace("<EOF>", "end of form")))
return Result() + build_method(
self, expr, unmangle(sroot), *parse_tree)
if root.startswith("."):
# (.split "test test") -> "test test".split()
# (.a.b.c x v1 v2) -> (.c (. x a b) v1 v2) -> x.a.b.c(v1, v2)
# Get the method name (the last named attribute
# in the chain of attributes)
attrs = [HySymbol(a).replace(root) for a in root.split(".")[1:]]
root = attrs.pop()
# Get the object we're calling the method on
# (extracted with the attribute access DSL)
# Skip past keywords and their arguments.
try:
kws, obj, rest = (
many(KEYWORD + FORM | unpack("mapping")) +
FORM +
many(FORM)).parse(args)
except NoParseError:
raise self._syntax_error(expr,
"attribute access requires object")
# Reconstruct `args` to exclude `obj`.
args = [x for p in kws for x in p] + list(rest)
if is_unpack("iterable", obj):
raise self._syntax_error(obj,
"can't call a method on an unpacking form")
func = self.compile(HyExpression(
[HySymbol(".").replace(root), obj] +
attrs))
# And get the method
func += asty.Attribute(root,
value=func.force_expr,
attr=ast_str(root),
ctx=ast.Load())
elif is_annotate_expression(root):
# Flatten and compile the annotation expression.
ann_expr = HyExpression(root + args).replace(root)
return self.compile_expression(ann_expr, allow_annotation_expression=True)
if not func:
func = self.compile(root)
args, ret, keywords = self._compile_collect(args, with_kwargs=True)
return func + ret + asty.Call(
expr, func=func.expr, args=args, keywords=keywords)
@builds_model(HyInteger, HyFloat, HyComplex)
def compile_numeric_literal(self, x):
f = {HyInteger: int,
HyFloat: float,
HyComplex: complex}[type(x)]
return asty.Num(x, n=f(x))
@builds_model(HySymbol)
def compile_symbol(self, symbol):
if "." in symbol:
glob, local = symbol.rsplit(".", 1)
if not glob:
raise self._syntax_error(symbol,
'cannot access attribute on anything other than a name (in order to get attributes of expressions, use `(. <expression> {attr})` or `(.{attr} <expression>)`)'.format(attr=local))
if not local:
raise self._syntax_error(symbol,
'cannot access empty attribute')
glob = HySymbol(glob).replace(symbol)
ret = self.compile_symbol(glob)
return asty.Attribute(
symbol,
value=ret,
attr=ast_str(local),
ctx=ast.Load())
if self.can_use_stdlib and ast_str(symbol) in self._stdlib:
self.imports[self._stdlib[ast_str(symbol)]].add(ast_str(symbol))
return asty.Name(symbol, id=ast_str(symbol), ctx=ast.Load())
@builds_model(HyKeyword)
def compile_keyword(self, obj):
ret = Result()
ret += asty.Call(
obj,
func=asty.Name(obj, id="HyKeyword", ctx=ast.Load()),
args=[asty.Str(obj, s=obj.name)],
keywords=[])
ret.add_imports("hy", {"HyKeyword"})
return ret
@builds_model(HyString, HyBytes)
def compile_string(self, string):
if type(string) is HyString and string.is_format:
# This is a format string (a.k.a. an f-string).
return self._format_string(string, str(string))
node = asty.Bytes if type(string) is HyBytes else asty.Str
f = bytes if type(string) is HyBytes else str
return node(string, s=f(string))
def _format_string(self, string, rest, allow_recursion=True):
values = []
ret = Result()
while True:
# Look for the next replacement field, and get the
# plain text before it.
match = re.search(r'\{\{?|\}\}?', rest)
if match:
literal_chars = rest[: match.start()]
if match.group() == '}':
raise self._syntax_error(string,
"f-string: single '}' is not allowed")
if match.group() in ('{{', '}}'):
# Doubled braces just add a single brace to the text.
literal_chars += match.group()[0]
rest = rest[match.end() :]
else:
literal_chars = rest
rest = ""
if literal_chars:
values.append(asty.Str(string, s = literal_chars))
if not rest:
break
if match.group() != '{':
continue
# Look for the end of the replacement field, allowing
# one more level of matched braces, but no deeper, and only
# if we can recurse.
match = re.match(
r'(?: \{ [^{}]* \} | [^{}]+ )* \}'
if allow_recursion
else r'[^{}]* \}',
rest, re.VERBOSE)
if not match:
raise self._syntax_error(string, 'f-string: mismatched braces')
item = rest[: match.end() - 1]
rest = rest[match.end() :]
# Parse the first form.
try:
model, item = parse_one_thing(item)
except (ValueError, LexException) as e:
raise self._syntax_error(string, "f-string: " + str(e))
# Look for a conversion character.
item = item.lstrip()
conversion = None
if item.startswith('!'):
conversion = item[1]
item = item[2:].lstrip()
# Look for a format specifier.
format_spec = None
if item.startswith(':'):
if allow_recursion:
ret += self._format_string(string,
item[1:],
allow_recursion=False)
format_spec = ret.force_expr
else:
format_spec = asty.Str(string, s=item[1:])
if PY36:
format_spec = asty.JoinedStr(string, values=[format_spec])
elif item:
raise self._syntax_error(string,
"f-string: trailing junk in field")
# Now, having finished compiling any recursively included
# forms, we can compile the first form that we parsed.
ret += self.compile(model)
if PY36:
values.append(asty.FormattedValue(
string,
conversion = -1 if conversion is None else ord(conversion),
format_spec = format_spec,
value = ret.force_expr))
else:
# Make an expression like:
# "{!r:{}}".format(value, format_spec)
values.append(asty.Call(string,
func = asty.Attribute(
string,
value = asty.Str(string, s =
'{' +
('!' + conversion if conversion else '') +
':{}}'),
attr = 'format', ctx = ast.Load()),
args = [
ret.force_expr,
format_spec or asty.Str(string, s = "")],
keywords = [], starargs = None, kwargs = None))
return ret + (
asty.JoinedStr(string, values = values)
if PY36
else reduce(
lambda x, y:
asty.BinOp(string, left = x, op = ast.Add(), right = y),
values))
@builds_model(HyList, HySet)
def compile_list(self, expression):
elts, ret, _ = self._compile_collect(expression)
node = {HyList: asty.List, HySet: asty.Set}[type(expression)]
return ret + node(expression, elts=elts, ctx=ast.Load())
@builds_model(HyDict)
def compile_dict(self, m):
keyvalues, ret, _ = self._compile_collect(m, dict_display=True)
return ret + asty.Dict(m, keys=keyvalues[::2], values=keyvalues[1::2])
def get_compiler_module(module=None, compiler=None, calling_frame=False):
"""Get a module object from a compiler, given module object,
string name of a module, and (optionally) the calling frame; otherwise,
raise an error."""
module = getattr(compiler, 'module', None) or module
if isinstance(module, str):
if module.startswith('<') and module.endswith('>'):
module = types.ModuleType(module)
else:
module = importlib.import_module(ast_str(module, piecewise=True))
if calling_frame and not module:
module = calling_module(n=2)
if not inspect.ismodule(module):
raise TypeError('Invalid module type: {}'.format(type(module)))
return module
def hy_eval(hytree, locals=None, module=None, ast_callback=None,
compiler=None, filename=None, source=None):
"""Evaluates a quoted expression and returns the value.
If you're evaluating hand-crafted AST trees, make sure the line numbers
are set properly. Try `fix_missing_locations` and related functions in the
Python `ast` library.
Examples
--------
=> (eval '(print "Hello World"))
"Hello World"
If you want to evaluate a string, use ``read-str`` to convert it to a
form first:
=> (eval (read-str "(+ 1 1)"))
2
Parameters
----------
hytree: HyObject
The Hy AST object to evaluate.
locals: dict, optional
Local environment in which to evaluate the Hy tree. Defaults to the
calling frame.
module: str or types.ModuleType, optional
Module, or name of the module, to which the Hy tree is assigned and
the global values are taken.
The module associated with `compiler` takes priority over this value.
When neither `module` nor `compiler` is specified, the calling frame's
module is used.
ast_callback: callable, optional
A callback that is passed the Hy compiled tree and resulting
expression object, in that order, after compilation but before
evaluation.
compiler: HyASTCompiler, optional
An existing Hy compiler to use for compilation. Also serves as
the `module` value when given.
filename: str, optional
The filename corresponding to the source for `tree`. This will be
overridden by the `filename` field of `tree`, if any; otherwise, it
defaults to "<string>". When `compiler` is given, its `filename` field
value is always used.
source: str, optional
A string containing the source code for `tree`. This will be
overridden by the `source` field of `tree`, if any; otherwise,
if `None`, an attempt will be made to obtain it from the module given by
`module`. When `compiler` is given, its `source` field value is always
used.
Returns
-------
out : Result of evaluating the Hy compiled tree.
"""
module = get_compiler_module(module, compiler, True)
if locals is None:
frame = inspect.stack()[1][0]
locals = inspect.getargvalues(frame).locals
if not isinstance(locals, dict):
raise TypeError("Locals must be a dictionary")
# Does the Hy AST object come with its own information?
filename = getattr(hytree, 'filename', filename) or '<string>'
source = getattr(hytree, 'source', source)
_ast, expr = hy_compile(hytree, module, get_expr=True,
compiler=compiler, filename=filename,
source=source)
if ast_callback:
ast_callback(_ast, expr)
# Two-step eval: eval() the body of the exec call
eval(ast_compile(_ast, filename, "exec"),
module.__dict__, locals)
# Then eval the expression context and return that
return eval(ast_compile(expr, filename, "eval"),
module.__dict__, locals)
def _module_file_source(module_name, filename, source):
"""Try to obtain missing filename and source information from a module name
without actually loading the module.
"""
if filename is None or source is None:
mod_loader = pkgutil.get_loader(module_name)
if mod_loader:
if filename is None:
filename = mod_loader.get_filename(module_name)
if source is None:
source = mod_loader.get_source(module_name)
# We need a non-None filename.
filename = filename or '<string>'
return filename, source
def hy_compile(tree, module, root=ast.Module, get_expr=False,
compiler=None, filename=None, source=None):
"""Compile a HyObject tree into a Python AST Module.
Parameters
----------
tree: HyObject
The Hy AST object to compile.
module: str or types.ModuleType, optional
Module, or name of the module, in which the Hy tree is evaluated.
The module associated with `compiler` takes priority over this value.
root: ast object, optional (ast.Module)
Root object for the Python AST tree.
get_expr: bool, optional (False)
If true, return a tuple with `(root_obj, last_expression)`.
compiler: HyASTCompiler, optional
An existing Hy compiler to use for compilation. Also serves as
the `module` value when given.
filename: str, optional
The filename corresponding to the source for `tree`. This will be
overridden by the `filename` field of `tree`, if any; otherwise, it
defaults to "<string>". When `compiler` is given, its `filename` field
value is always used.
source: str, optional
A string containing the source code for `tree`. This will be
overridden by the `source` field of `tree`, if any; otherwise,
if `None`, an attempt will be made to obtain it from the module given by
`module`. When `compiler` is given, its `source` field value is always
used.
Returns
-------
out : A Python AST tree
"""
module = get_compiler_module(module, compiler, False)
if isinstance(module, str):
if module.startswith('<') and module.endswith('>'):
module = types.ModuleType(module)
else:
module = importlib.import_module(ast_str(module, piecewise=True))
if not inspect.ismodule(module):
raise TypeError('Invalid module type: {}'.format(type(module)))
filename = getattr(tree, 'filename', filename)
source = getattr(tree, 'source', source)
tree = wrap_value(tree)
if not isinstance(tree, HyObject):
raise TypeError("`tree` must be a HyObject or capable of "
"being promoted to one")
compiler = compiler or HyASTCompiler(module, filename=filename, source=source)
result = compiler.compile(tree)
expr = result.force_expr
if not get_expr:
result += result.expr_as_stmt()
body = []
# Pull out a single docstring and prepend to the resulting body.
if (len(result.stmts) > 0 and
issubclass(root, ast.Module) and
isinstance(result.stmts[0], ast.Expr) and
isinstance(result.stmts[0].value, ast.Str)):
body += [result.stmts.pop(0)]
body += sorted(compiler.imports_as_stmts(tree) + result.stmts,
key=lambda a: not (isinstance(a, ast.ImportFrom) and
a.module == '__future__'))
ret = root(body=body, type_ignores=[])
if get_expr:
expr = ast.Expression(body=expr)
ret = (ret, expr)
return ret