| 1 | n/a | """Check for errs in the AST. |
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| 2 | n/a | |
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| 3 | n/a | The Python parser does not catch all syntax errors. Others, like |
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| 4 | n/a | assignments with invalid targets, are caught in the code generation |
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| 5 | n/a | phase. |
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| 6 | n/a | |
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| 7 | n/a | The compiler package catches some errors in the transformer module. |
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| 8 | n/a | But it seems clearer to write checkers that use the AST to detect |
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| 9 | n/a | errors. |
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| 10 | 2 | """ |
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| 11 | n/a | |
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| 12 | 2 | from compiler import ast, walk |
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| 13 | n/a | |
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| 14 | 2 | def check(tree, multi=None): |
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| 15 | 31 | v = SyntaxErrorChecker(multi) |
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| 16 | 31 | walk(tree, v) |
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| 17 | 31 | return v.errors |
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| 18 | n/a | |
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| 19 | 4 | class SyntaxErrorChecker: |
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| 20 | 2 | """A visitor to find syntax errors in the AST.""" |
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| 21 | n/a | |
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| 22 | 2 | def __init__(self, multi=None): |
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| 23 | n/a | """Create new visitor object. |
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| 24 | n/a | |
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| 25 | n/a | If optional argument multi is not None, then print messages |
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| 26 | n/a | for each error rather than raising a SyntaxError for the |
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| 27 | n/a | first. |
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| 28 | n/a | """ |
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| 29 | 31 | self.multi = multi |
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| 30 | 31 | self.errors = 0 |
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| 31 | n/a | |
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| 32 | 2 | def error(self, node, msg): |
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| 33 | 0 | self.errors = self.errors + 1 |
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| 34 | 0 | if self.multi is not None: |
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| 35 | 0 | print "%s:%s: %s" % (node.filename, node.lineno, msg) |
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| 36 | n/a | else: |
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| 37 | 0 | raise SyntaxError, "%s (%s:%s)" % (msg, node.filename, node.lineno) |
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| 38 | n/a | |
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| 39 | 2 | def visitAssign(self, node): |
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| 40 | n/a | # the transformer module handles many of these |
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| 41 | 971 | pass |
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| 42 | n/a | ## for target in node.nodes: |
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| 43 | n/a | ## if isinstance(target, ast.AssList): |
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| 44 | n/a | ## if target.lineno is None: |
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| 45 | n/a | ## target.lineno = node.lineno |
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| 46 | n/a | ## self.error(target, "can't assign to list comprehension") |
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