diff options
Diffstat (limited to 'Demo/parser/unparse.py')
| -rw-r--r-- | Demo/parser/unparse.py | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/Demo/parser/unparse.py b/Demo/parser/unparse.py index 2c383a5eac..048f8ca432 100644 --- a/Demo/parser/unparse.py +++ b/Demo/parser/unparse.py @@ -1,5 +1,6 @@ "Usage: unparse.py <path to source file>" import sys +import math import ast import tokenize import io @@ -302,17 +303,22 @@ class Unparser: self.write("`") def _Num(self, t): - # Add parentheses around numeric literals to avoid: - # - # (1) turning (-1)**2 into -1**2, and - # (2) turning 3 .__abs__() into 3.__abs__() - # - # For (1), note that Python doesn't actually have negative - # numeric literals, but (at least in Python 2.x) there's a CST - # transformation that can produce negative Nums in the AST. - self.write("(") - self.write(repr(t.n)) - self.write(")") + if isinstance(t.n, float): + # A float literal should be nonnegative, and not a nan. + # It could be an infinity, though; in that case we + # substitute an overflowing decimal value. + assert not math.isnan(t.n) + assert math.copysign(1.0, t.n) > 0.0 + if math.isinf(t.n): + self.write("1e" + repr(sys.float_info.max_10_exp + 1)) + else: + self.write(repr(t.n)) + else: + # Parenthesize integer literals to avoid turning + # "3 .__abs__()" into "3.__abs__()". + self.write("(") + self.write(repr(t.n)) + self.write(")") def _List(self, t): self.write("[") @@ -539,10 +545,12 @@ class Unparser: 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) |