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Diffstat (limited to 'third_party/python/Mako/mako/ast.py')
| -rw-r--r-- | third_party/python/Mako/mako/ast.py | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/third_party/python/Mako/mako/ast.py b/third_party/python/Mako/mako/ast.py new file mode 100644 index 0000000000..cfae28062c --- /dev/null +++ b/third_party/python/Mako/mako/ast.py @@ -0,0 +1,205 @@ +# mako/ast.py +# Copyright 2006-2020 the Mako authors and contributors <see AUTHORS file> +# +# This module is part of Mako and is released under +# the MIT License: http://www.opensource.org/licenses/mit-license.php + +"""utilities for analyzing expressions and blocks of Python +code, as well as generating Python from AST nodes""" + +import re + +from mako import compat +from mako import exceptions +from mako import pyparser + + +class PythonCode(object): + + """represents information about a string containing Python code""" + + def __init__(self, code, **exception_kwargs): + self.code = code + + # represents all identifiers which are assigned to at some point in + # the code + self.declared_identifiers = set() + + # represents all identifiers which are referenced before their + # assignment, if any + self.undeclared_identifiers = set() + + # note that an identifier can be in both the undeclared and declared + # lists. + + # using AST to parse instead of using code.co_varnames, + # code.co_names has several advantages: + # - we can locate an identifier as "undeclared" even if + # its declared later in the same block of code + # - AST is less likely to break with version changes + # (for example, the behavior of co_names changed a little bit + # in python version 2.5) + if isinstance(code, compat.string_types): + expr = pyparser.parse(code.lstrip(), "exec", **exception_kwargs) + else: + expr = code + + f = pyparser.FindIdentifiers(self, **exception_kwargs) + f.visit(expr) + + +class ArgumentList(object): + + """parses a fragment of code as a comma-separated list of expressions""" + + def __init__(self, code, **exception_kwargs): + self.codeargs = [] + self.args = [] + self.declared_identifiers = set() + self.undeclared_identifiers = set() + if isinstance(code, compat.string_types): + if re.match(r"\S", code) and not re.match(r",\s*$", code): + # if theres text and no trailing comma, insure its parsed + # as a tuple by adding a trailing comma + code += "," + expr = pyparser.parse(code, "exec", **exception_kwargs) + else: + expr = code + + f = pyparser.FindTuple(self, PythonCode, **exception_kwargs) + f.visit(expr) + + +class PythonFragment(PythonCode): + + """extends PythonCode to provide identifier lookups in partial control + statements + + e.g.:: + + for x in 5: + elif y==9: + except (MyException, e): + + """ + + def __init__(self, code, **exception_kwargs): + m = re.match(r"^(\w+)(?:\s+(.*?))?:\s*(#|$)", code.strip(), re.S) + if not m: + raise exceptions.CompileException( + "Fragment '%s' is not a partial control statement" % code, + **exception_kwargs + ) + if m.group(3): + code = code[: m.start(3)] + (keyword, expr) = m.group(1, 2) + if keyword in ["for", "if", "while"]: + code = code + "pass" + elif keyword == "try": + code = code + "pass\nexcept:pass" + elif keyword == "elif" or keyword == "else": + code = "if False:pass\n" + code + "pass" + elif keyword == "except": + code = "try:pass\n" + code + "pass" + elif keyword == "with": + code = code + "pass" + else: + raise exceptions.CompileException( + "Unsupported control keyword: '%s'" % keyword, + **exception_kwargs + ) + super(PythonFragment, self).__init__(code, **exception_kwargs) + + +class FunctionDecl(object): + + """function declaration""" + + def __init__(self, code, allow_kwargs=True, **exception_kwargs): + self.code = code + expr = pyparser.parse(code, "exec", **exception_kwargs) + + f = pyparser.ParseFunc(self, **exception_kwargs) + f.visit(expr) + if not hasattr(self, "funcname"): + raise exceptions.CompileException( + "Code '%s' is not a function declaration" % code, + **exception_kwargs + ) + if not allow_kwargs and self.kwargs: + raise exceptions.CompileException( + "'**%s' keyword argument not allowed here" + % self.kwargnames[-1], + **exception_kwargs + ) + + def get_argument_expressions(self, as_call=False): + """Return the argument declarations of this FunctionDecl as a printable + list. + + By default the return value is appropriate for writing in a ``def``; + set `as_call` to true to build arguments to be passed to the function + instead (assuming locals with the same names as the arguments exist). + """ + + namedecls = [] + + # Build in reverse order, since defaults and slurpy args come last + argnames = self.argnames[::-1] + kwargnames = self.kwargnames[::-1] + defaults = self.defaults[::-1] + kwdefaults = self.kwdefaults[::-1] + + # Named arguments + if self.kwargs: + namedecls.append("**" + kwargnames.pop(0)) + + for name in kwargnames: + # Keyword-only arguments must always be used by name, so even if + # this is a call, print out `foo=foo` + if as_call: + namedecls.append("%s=%s" % (name, name)) + elif kwdefaults: + default = kwdefaults.pop(0) + if default is None: + # The AST always gives kwargs a default, since you can do + # `def foo(*, a=1, b, c=3)` + namedecls.append(name) + else: + namedecls.append( + "%s=%s" + % (name, pyparser.ExpressionGenerator(default).value()) + ) + else: + namedecls.append(name) + + # Positional arguments + if self.varargs: + namedecls.append("*" + argnames.pop(0)) + + for name in argnames: + if as_call or not defaults: + namedecls.append(name) + else: + default = defaults.pop(0) + namedecls.append( + "%s=%s" + % (name, pyparser.ExpressionGenerator(default).value()) + ) + + namedecls.reverse() + return namedecls + + @property + def allargnames(self): + return tuple(self.argnames) + tuple(self.kwargnames) + + +class FunctionArgs(FunctionDecl): + + """the argument portion of a function declaration""" + + def __init__(self, code, **kwargs): + super(FunctionArgs, self).__init__( + "def ANON(%s):pass" % code, **kwargs + ) |