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nac3-spec
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Code Issues 14 Pull Requests Releases Wiki Activity

added name clash check

pull/14/head
pca006132 2020-12-21 15:08:55 +08:00 committed by pca006132
parent db342784bc
commit 594fbf1061
2 changed files with 8 additions and 0 deletions
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6
toy-impl/parse_expr.py
View File

@ -208,6 +208,8 @@ def parse_if_expr(ctx: Context,
def parse_binding(name, ty):
if isinstance(name, ast.Name):
if name.id == '_':
return {}
return {name.id: ty}
elif isinstance(name, ast.Tuple):
if not isinstance(ty, TupleType):
@ -216,7 +218,11 @@ def parse_binding(name, ty):
raise CustomError(f'pattern matching length mismatch')
result = {}
for x, y in zip(name.elts, ty.params):
binding = parse_binding(x, y)
expected = len(result) + len(binding)
result |= parse_binding(x, y)
if len(result) != expected:
raise CustomError('variable name clash')
return result
else:
raise CustomError(f'binding to {name} is not supported')

2
toy-impl/test_expr.py
View File

@ -83,6 +83,8 @@ test_expr('[x for x in [1, 2, 3]]', {})
test_expr('[1 for x in [1, 2, 3] if x > 2]', {})
test_expr('[a + a for x in [1, 2, 3] if x > 2]', {'a': I})
test_expr('[a for a, b in [(1, 2), (2, 3), (3, 4)] if b > 2]', {})
test_expr('[a for a, a in [(1, 2), (2, 3), (3, 4)] if b > 2]', {})
test_expr('[1 for _, _ in [(1, 2), (2, 3), (3, 4)]]', {})
test_expr('[b for a, b in [(1, (2, 3)), (2, (3, 4)), (3, (4, 5))] if b > 2]', {})
test_expr('[b for a, b in [(1, (2, 3)), (2, (3, 4)), (3, (4, 5))]]', {})
test_expr('[b for a, (b, c) in [(1, (2, 3)), (2, (3, 4)), (3, (4, 5))] if b > 2]', {})