From 8e1d334b7b5d8dc5d1e5a18e6b2a7a7e0272db8a Mon Sep 17 00:00:00 2001 From: Sebastien Bourdeauducq Date: Sat, 24 May 2014 23:05:48 +0200 Subject: [PATCH] Add unparser (from Python source) --- artiq/unparse.py | 564 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 564 insertions(+) create mode 100644 artiq/unparse.py diff --git a/artiq/unparse.py b/artiq/unparse.py new file mode 100644 index 000000000..be280132f --- /dev/null +++ b/artiq/unparse.py @@ -0,0 +1,564 @@ +import sys +import ast +import os + +# Large float and imaginary literals get turned into infinities in the AST. +# We unparse those infinities to INFSTR. +INFSTR = "1e" + repr(sys.float_info.max_10_exp + 1) + +def interleave(inter, f, seq): + """Call f on each item in seq, calling inter() in between. + """ + seq = iter(seq) + try: + f(next(seq)) + except StopIteration: + pass + else: + for x in seq: + inter() + f(x) + +class Unparser: + """Methods in this class recursively traverse an AST and + output source code for the abstract syntax; original formatting + is disregarded. """ + + def __init__(self, tree, file = sys.stdout): + """Unparser(tree, file=sys.stdout) -> None. + Print the source for tree to file.""" + self.f = file + self._indent = 0 + self.dispatch(tree) + print("", file=self.f) + self.f.flush() + + def fill(self, text = ""): + "Indent a piece of text, according to the current indentation level" + self.f.write("\n"+" "*self._indent + text) + + def write(self, text): + "Append a piece of text to the current line." + self.f.write(text) + + def enter(self): + "Print ':', and increase the indentation." + self.write(":") + self._indent += 1 + + def leave(self): + "Decrease the indentation level." + self._indent -= 1 + + def dispatch(self, tree): + "Dispatcher function, dispatching tree type T to method _T." + if isinstance(tree, list): + for t in tree: + self.dispatch(t) + return + meth = getattr(self, "_"+tree.__class__.__name__) + meth(tree) + + + ############### Unparsing methods ###################### + # There should be one method per concrete grammar type # + # Constructors should be grouped by sum type. Ideally, # + # this would follow the order in the grammar, but # + # currently doesn't. # + ######################################################## + + def _Module(self, tree): + for stmt in tree.body: + self.dispatch(stmt) + + # stmt + def _Expr(self, tree): + self.fill() + self.dispatch(tree.value) + + def _Import(self, t): + self.fill("import ") + interleave(lambda: self.write(", "), self.dispatch, t.names) + + def _ImportFrom(self, t): + self.fill("from ") + self.write("." * t.level) + if t.module: + self.write(t.module) + self.write(" import ") + interleave(lambda: self.write(", "), self.dispatch, t.names) + + def _Assign(self, t): + self.fill() + for target in t.targets: + self.dispatch(target) + self.write(" = ") + self.dispatch(t.value) + + def _AugAssign(self, t): + self.fill() + self.dispatch(t.target) + self.write(" "+self.binop[t.op.__class__.__name__]+"= ") + self.dispatch(t.value) + + def _Return(self, t): + self.fill("return") + if t.value: + self.write(" ") + self.dispatch(t.value) + + def _Pass(self, t): + self.fill("pass") + + def _Break(self, t): + self.fill("break") + + def _Continue(self, t): + self.fill("continue") + + def _Delete(self, t): + self.fill("del ") + interleave(lambda: self.write(", "), self.dispatch, t.targets) + + def _Assert(self, t): + self.fill("assert ") + self.dispatch(t.test) + if t.msg: + self.write(", ") + self.dispatch(t.msg) + + def _Global(self, t): + self.fill("global ") + interleave(lambda: self.write(", "), self.write, t.names) + + def _Nonlocal(self, t): + self.fill("nonlocal ") + interleave(lambda: self.write(", "), self.write, t.names) + + def _Yield(self, t): + self.write("(") + self.write("yield") + if t.value: + self.write(" ") + self.dispatch(t.value) + self.write(")") + + def _YieldFrom(self, t): + self.write("(") + self.write("yield from") + if t.value: + self.write(" ") + self.dispatch(t.value) + self.write(")") + + def _Raise(self, t): + self.fill("raise") + if not t.exc: + assert not t.cause + return + self.write(" ") + self.dispatch(t.exc) + if t.cause: + self.write(" from ") + self.dispatch(t.cause) + + def _Try(self, t): + self.fill("try") + self.enter() + self.dispatch(t.body) + self.leave() + for ex in t.handlers: + self.dispatch(ex) + if t.orelse: + self.fill("else") + self.enter() + self.dispatch(t.orelse) + self.leave() + if t.finalbody: + self.fill("finally") + self.enter() + self.dispatch(t.finalbody) + self.leave() + + def _ExceptHandler(self, t): + self.fill("except") + if t.type: + self.write(" ") + self.dispatch(t.type) + if t.name: + self.write(" as ") + self.write(t.name) + self.enter() + self.dispatch(t.body) + self.leave() + + def _ClassDef(self, t): + self.write("\n") + for deco in t.decorator_list: + self.fill("@") + self.dispatch(deco) + self.fill("class "+t.name) + self.write("(") + comma = False + for e in t.bases: + if comma: self.write(", ") + else: comma = True + self.dispatch(e) + for e in t.keywords: + if comma: self.write(", ") + else: comma = True + self.dispatch(e) + if t.starargs: + if comma: self.write(", ") + else: comma = True + self.write("*") + self.dispatch(t.starargs) + if t.kwargs: + if comma: self.write(", ") + else: comma = True + self.write("**") + self.dispatch(t.kwargs) + self.write(")") + + self.enter() + self.dispatch(t.body) + self.leave() + + def _FunctionDef(self, t): + self.write("\n") + for deco in t.decorator_list: + self.fill("@") + self.dispatch(deco) + self.fill("def "+t.name + "(") + self.dispatch(t.args) + self.write(")") + if t.returns: + self.write(" -> ") + self.dispatch(t.returns) + self.enter() + self.dispatch(t.body) + self.leave() + + def _For(self, t): + self.fill("for ") + self.dispatch(t.target) + self.write(" in ") + self.dispatch(t.iter) + self.enter() + self.dispatch(t.body) + self.leave() + if t.orelse: + self.fill("else") + self.enter() + self.dispatch(t.orelse) + self.leave() + + def _If(self, t): + self.fill("if ") + self.dispatch(t.test) + self.enter() + self.dispatch(t.body) + self.leave() + # collapse nested ifs into equivalent elifs. + while (t.orelse and len(t.orelse) == 1 and + isinstance(t.orelse[0], ast.If)): + t = t.orelse[0] + self.fill("elif ") + self.dispatch(t.test) + self.enter() + self.dispatch(t.body) + self.leave() + # final else + if t.orelse: + self.fill("else") + self.enter() + self.dispatch(t.orelse) + self.leave() + + def _While(self, t): + self.fill("while ") + self.dispatch(t.test) + self.enter() + self.dispatch(t.body) + self.leave() + if t.orelse: + self.fill("else") + self.enter() + self.dispatch(t.orelse) + self.leave() + + def _With(self, t): + self.fill("with ") + interleave(lambda: self.write(", "), self.dispatch, t.items) + self.enter() + self.dispatch(t.body) + self.leave() + + # expr + def _Bytes(self, t): + self.write(repr(t.s)) + + def _Str(self, tree): + self.write(repr(tree.s)) + + def _Name(self, t): + self.write(t.id) + + def _NameConstant(self, t): + self.write(repr(t.value)) + + def _Num(self, t): + # Substitute overflowing decimal literal for AST infinities. + self.write(repr(t.n).replace("inf", INFSTR)) + + def _List(self, t): + self.write("[") + interleave(lambda: self.write(", "), self.dispatch, t.elts) + self.write("]") + + def _ListComp(self, t): + self.write("[") + self.dispatch(t.elt) + for gen in t.generators: + self.dispatch(gen) + self.write("]") + + def _GeneratorExp(self, t): + self.write("(") + self.dispatch(t.elt) + for gen in t.generators: + self.dispatch(gen) + self.write(")") + + def _SetComp(self, t): + self.write("{") + self.dispatch(t.elt) + for gen in t.generators: + self.dispatch(gen) + self.write("}") + + def _DictComp(self, t): + self.write("{") + self.dispatch(t.key) + self.write(": ") + self.dispatch(t.value) + for gen in t.generators: + self.dispatch(gen) + self.write("}") + + def _comprehension(self, t): + self.write(" for ") + self.dispatch(t.target) + self.write(" in ") + self.dispatch(t.iter) + for if_clause in t.ifs: + self.write(" if ") + self.dispatch(if_clause) + + def _IfExp(self, t): + self.write("(") + self.dispatch(t.body) + self.write(" if ") + self.dispatch(t.test) + self.write(" else ") + self.dispatch(t.orelse) + self.write(")") + + def _Set(self, t): + assert(t.elts) # should be at least one element + self.write("{") + interleave(lambda: self.write(", "), self.dispatch, t.elts) + self.write("}") + + def _Dict(self, t): + self.write("{") + def write_pair(pair): + (k, v) = pair + self.dispatch(k) + self.write(": ") + self.dispatch(v) + interleave(lambda: self.write(", "), write_pair, zip(t.keys, t.values)) + self.write("}") + + def _Tuple(self, t): + self.write("(") + if len(t.elts) == 1: + (elt,) = t.elts + self.dispatch(elt) + self.write(",") + else: + interleave(lambda: self.write(", "), self.dispatch, t.elts) + self.write(")") + + unop = {"Invert":"~", "Not": "not", "UAdd":"+", "USub":"-"} + def _UnaryOp(self, t): + self.write("(") + self.write(self.unop[t.op.__class__.__name__]) + self.write(" ") + self.dispatch(t.operand) + self.write(")") + + binop = { "Add":"+", "Sub":"-", "Mult":"*", "Div":"/", "Mod":"%", + "LShift":"<<", "RShift":">>", "BitOr":"|", "BitXor":"^", "BitAnd":"&", + "FloorDiv":"//", "Pow": "**"} + def _BinOp(self, t): + self.write("(") + self.dispatch(t.left) + self.write(" " + self.binop[t.op.__class__.__name__] + " ") + self.dispatch(t.right) + self.write(")") + + cmpops = {"Eq":"==", "NotEq":"!=", "Lt":"<", "LtE":"<=", "Gt":">", "GtE":">=", + "Is":"is", "IsNot":"is not", "In":"in", "NotIn":"not in"} + def _Compare(self, t): + self.write("(") + self.dispatch(t.left) + for o, e in zip(t.ops, t.comparators): + self.write(" " + self.cmpops[o.__class__.__name__] + " ") + self.dispatch(e) + self.write(")") + + boolops = {ast.And: 'and', ast.Or: 'or'} + def _BoolOp(self, t): + self.write("(") + s = " %s " % self.boolops[t.op.__class__] + interleave(lambda: self.write(s), self.dispatch, t.values) + self.write(")") + + def _Attribute(self,t): + self.dispatch(t.value) + # Special case: 3.__abs__() is a syntax error, so if t.value + # is an integer literal then we need to either parenthesize + # it or add an extra space to get 3 .__abs__(). + if isinstance(t.value, ast.Num) and isinstance(t.value.n, int): + self.write(" ") + self.write(".") + self.write(t.attr) + + def _Call(self, t): + self.dispatch(t.func) + self.write("(") + comma = False + for e in t.args: + if comma: self.write(", ") + else: comma = True + self.dispatch(e) + for e in t.keywords: + if comma: self.write(", ") + else: comma = True + self.dispatch(e) + if t.starargs: + if comma: self.write(", ") + else: comma = True + self.write("*") + self.dispatch(t.starargs) + if t.kwargs: + if comma: self.write(", ") + else: comma = True + self.write("**") + self.dispatch(t.kwargs) + self.write(")") + + def _Subscript(self, t): + self.dispatch(t.value) + self.write("[") + self.dispatch(t.slice) + self.write("]") + + def _Starred(self, t): + self.write("*") + self.dispatch(t.value) + + # slice + def _Ellipsis(self, t): + self.write("...") + + def _Index(self, t): + self.dispatch(t.value) + + def _Slice(self, t): + if t.lower: + self.dispatch(t.lower) + self.write(":") + if t.upper: + self.dispatch(t.upper) + if t.step: + self.write(":") + self.dispatch(t.step) + + def _ExtSlice(self, t): + interleave(lambda: self.write(', '), self.dispatch, t.dims) + + # argument + def _arg(self, t): + self.write(t.arg) + if t.annotation: + self.write(": ") + self.dispatch(t.annotation) + + # others + def _arguments(self, t): + first = True + # normal arguments + defaults = [None] * (len(t.args) - len(t.defaults)) + t.defaults + for a, d in zip(t.args, defaults): + if first:first = False + else: self.write(", ") + self.dispatch(a) + if d: + self.write("=") + self.dispatch(d) + + # varargs, or bare '*' if no varargs but keyword-only arguments present + if t.vararg or t.kwonlyargs: + if first:first = False + else: self.write(", ") + self.write("*") + if t.vararg: + self.write(t.vararg.arg) + if t.vararg.annotation: + self.write(": ") + self.dispatch(t.vararg.annotation) + + # keyword-only arguments + if t.kwonlyargs: + for a, d in zip(t.kwonlyargs, t.kw_defaults): + if first:first = False + else: self.write(", ") + self.dispatch(a), + if d: + self.write("=") + self.dispatch(d) + + # kwargs + if t.kwarg: + if first:first = False + else: self.write(", ") + self.write("**"+t.kwarg.arg) + if t.kwarg.annotation: + self.write(": ") + self.dispatch(t.kwarg.annotation) + + def _keyword(self, t): + self.write(t.arg) + self.write("=") + self.dispatch(t.value) + + def _Lambda(self, t): + self.write("(") + self.write("lambda ") + self.dispatch(t.args) + self.write(": ") + self.dispatch(t.body) + self.write(")") + + def _alias(self, t): + self.write(t.name) + if t.asname: + self.write(" as "+t.asname) + + def _withitem(self, t): + self.dispatch(t.context_expr) + if t.optional_vars: + self.write(" as ") + self.dispatch(t.optional_vars)