KiBot/kibot/mcpyrate/repl/console.py

213 lines
9.6 KiB
Python

# -*- coding: utf-8 -*-
"""mcpyrate-enabled `code.InteractiveConsole`.
Special commands:
- `obj?` shows obj's docstring, `obj??` shows its source code.
- `macros?` shows macro bindings.
- `macro(f)` binds a function as a macro. Works also as a decorator.
"""
# Based on `imacropy.console.MacroConsole` by Juha Jeronen,
# which was based on `macropy.core.MacroConsole` by Li Haoyi,
# Justin Holmgren, Alberto Berti and all the other contributors,
# 2013-2019. Used under the MIT license.
# https://github.com/azazel75/macropy
# https://github.com/Technologicat/imacropy
__all__ = ["MacroConsole"]
import ast
import code
import copy
import sys
import textwrap
from .. import __version__ as mcpyrate_version
from ..compiler import create_module
from ..core import MacroExpansionError
from ..debug import format_bindings
from ..expander import find_macros, MacroExpander, global_postprocess
from .utils import get_makemacro_sourcecode
# Boot up `mcpyrate` so that the REPL can import modules that use macros.
# Despite the meta-levels, there's just one global importer for the Python process.
from .. import activate # noqa: F401
_magic_module_name = "__mcpyrate_repl_self__"
class MacroConsole(code.InteractiveConsole):
def __init__(self, locals=None, filename="<interactive input>"):
"""Parameters like in `code.InteractiveConsole`."""
self.expander = MacroExpander(bindings={}, filename=filename)
self._macro_bindings_changed = False
if locals is None:
locals = {}
# Lucky that both meta-levels speak the same language, eh?
locals["__macro_expander__"] = self.expander
# support `from __self__ import macros, ...`
#
# To do this, we need the top-level variables in the REPL to be stored
# in the namespace of a module, so that `find_macros` can look them up.
#
# We create a module dynamically. The one obvious way would be to then
# replace the `__dict__` of that module with the given `locals`, but
# `types.ModuleType` is special in that the `__dict__` binding itself
# is read-only:
# https://docs.python.org/3/library/stdtypes.html#modules
#
# This leaves two possible solutions:
#
# a. Keep our magic module separate from `locals`, and shallow-copy
# the user namespace into its `__dict__` after each REPL input.
# The magic module's namespace is only used for macro lookups.
#
# + Behaves exactly like `code.InteractiveConsole` in that the
# user-given `locals` *is* the dict where the top-level variables
# are stored. So the user can keep a reference to that dict, and
# they will see any changes made by assigning to top-level
# variables in the REPL.
#
# - May slow down the REPL when a lot of top-level variables exist.
# Likely not a problem in practice.
#
# b. Use the module's `__dict__` as the local namespace of the REPL
# session. At startup, update it from `locals`, to install any
# user-provided initial variable bindings for the session.
#
# + Elegant. No extra copying.
#
# - Behavior does not match `code.InteractiveConsole`. The
# `locals` argument only provides initial values; any updates
# made during the REPL session are stored in the module's
# `__dict__`, which is a different dict instance. Hence the user
# will not see any changes made by assigning to top-level
# variables in the REPL.
#
# We currently use strategy a., for least astonishment.
#
magic_module = create_module(dotted_name=_magic_module_name, filename=filename)
self.magic_module_metadata = copy.copy(magic_module.__dict__)
super().__init__(locals, filename)
# Support for special REPL commands.
self._internal_execute(get_makemacro_sourcecode())
self._internal_execute("import mcpyrate.repl.utils")
def _internal_execute(self, source):
"""Execute given source in the console session.
This is support magic for internal operation of the console
session itself, e.g. for auto-loading macro functions.
The source must be pure Python, i.e. no macros.
The source is NOT added to the session history.
This bypasses `runsource`, so it too can use this function.
"""
source = textwrap.dedent(source)
tree = ast.parse(source, self.filename)
tree = ast.Interactive(tree.body)
code = compile(tree, "<console internal>", "single", self.compile.compiler.flags, 1)
self.runcode(code)
def interact(self, banner=None, exitmsg=None):
"""See `code.InteractiveConsole.interact`.
The only thing we customize here is that if `banner is None`, in which case
`code.InteractiveConsole` will print its default banner, we print help for
our special commands and a line containing the `mcpyrate` version before that
default banner.
"""
if banner is None:
self.write(f"mcpyrate {mcpyrate_version} -- Advanced macro expander for Python.\n")
self.write("- obj? to view obj's docstring, and obj?? to view its source code.\n")
self.write("- macros? to view macro bindings.\n")
self.write("- macro(f) to bind function f as a macro. Works also as a decorator.\n")
return super().interact(banner, exitmsg)
def runsource(self, source, filename="<interactive input>", symbol="single"):
# Special REPL commands.
if source == "macros?":
self.write(format_bindings(self.expander, color=True))
return False # complete input
elif source.endswith("??"):
# Use `_internal_execute` instead of `runsource` to prevent expansion of name macros.
return self._internal_execute(f"mcpyrate.repl.utils.sourcecode({source[:-2]})")
elif source.endswith("?"):
return self._internal_execute(f"mcpyrate.repl.utils.doc({source[:-1]})")
try:
code = self.compile(source, filename, symbol)
except (OverflowError, SyntaxError, ValueError):
code = ""
if code is None: # incomplete input
return True
try:
# TODO: If we want to support dialects in the REPL, this is where to do it.
# Look at `mcpyrate.compiler.compile`.
tree = ast.parse(source, self.filename)
# macro-imports (this will import the modules)
sys.modules[_magic_module_name].__dict__.clear()
sys.modules[_magic_module_name].__dict__.update(self.locals) # for self-macro-imports
# We treat the initial magic module metadata as write-protected: even if the user
# defines a variable of the same name in the user namespace, the metadata fields
# in the magic module won't be overwritten.
sys.modules[_magic_module_name].__dict__.update(self.magic_module_metadata)
bindings = find_macros(tree, filename=self.expander.filename,
reload=True, self_module=_magic_module_name)
if bindings:
self._macro_bindings_changed = True
self.expander.bindings.update(bindings)
tree = self.expander.visit(tree)
tree = global_postprocess(tree)
tree = ast.Interactive(tree.body)
code = compile(tree, filename, symbol, self.compile.compiler.flags, 1)
except (OverflowError, SyntaxError, ValueError, MacroExpansionError):
self.showsyntaxerror(filename)
return False # erroneous input
except ModuleNotFoundError as err: # during macro module lookup
# In this case, the standard stack trace is long and points only to our code and the stdlib,
# not the erroneous input that's the actual culprit. Better ignore it, and emulate showsyntaxerror.
# TODO: support sys.excepthook.
# TODO: Look at `code.InteractiveConsole.showsyntaxerror` for how to do that.
self.write(f"{err.__class__.__name__}: {str(err)}\n")
return False # erroneous input
except ImportError as err: # during macro lookup in a successfully imported module
self.write(f"{err.__class__.__name__}: {str(err)}\n")
return False # erroneous input
self.runcode(code)
self._refresh_macro_functions()
return False # Successfully compiled. `runcode` takes care of any runtime failures.
def _refresh_macro_functions(self):
"""Refresh macro function imports.
Called after successfully compiling and running an input, so that
`some_macro.__doc__` points to the right docstring.
"""
if not self._macro_bindings_changed:
return
self._macro_bindings_changed = False
for asname, function in self.expander.bindings.items():
# Catch broken bindings due to erroneous imports in user code
# (e.g. accidentally to a module object instead of to a function object)
if not (hasattr(function, "__module__") and hasattr(function, "__qualname__")):
continue
if not function.__module__: # Macros defined in the REPL have `__module__=None`.
continue
try:
source = f"from {function.__module__} import {function.__qualname__} as {asname}"
self._internal_execute(source)
except (ModuleNotFoundError, ImportError):
pass