cpython/Lib/compiler/syntax.py
Jeremy Hylton 2e4cc7e0d8 Last set of change to get regression tests to pass
Remove the only test in the syntax module.  It ends up that the
transformer must handle this error case.

In the transformer, check for a list compression in com_assign_list()
by looking for a list_for node where a comma is expected.

In pycodegen.compile() re-raise the SyntaxError rather than catching
it and exiting
2001-09-17 19:33:48 +00:00

47 lines
1.4 KiB
Python

"""Check for errs in the AST.
The Python parser does not catch all syntax errors. Others, like
assignments with invalid targets, are caught in the code generation
phase.
The compiler package catches some errors in the transformer module.
But it seems clearer to write checkers that use the AST to detect
errors.
"""
from compiler import ast, walk
def check(tree, multi=None):
v = SyntaxErrorChecker(multi)
walk(tree, v)
return v.errors
class SyntaxErrorChecker:
"""A visitor to find syntax errors in the AST."""
def __init__(self, multi=None):
"""Create new visitor object.
If optional argument multi is not None, then print messages
for each error rather than raising a SyntaxError for the
first.
"""
self.multi = multi
self.errors = 0
def error(self, node, msg):
self.errors = self.errors + 1
if self.multi is not None:
print "%s:%s: %s" % (node.filename, node.lineno, msg)
else:
raise SyntaxError, "%s (%s:%s)" % (msg, node.filename, node.lineno)
def visitAssign(self, node):
# the transformer module handles many of these
for target in node.nodes:
pass
## if isinstance(target, ast.AssList):
## if target.lineno is None:
## target.lineno = node.lineno
## self.error(target, "can't assign to list comprehension")