29 lines
793 B
Text
29 lines
793 B
Text
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# Copyright 2006 Google, Inc. All Rights Reserved.
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# Licensed to PSF under a Contributor Agreement.
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# A grammar to describe tree matching patterns.
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# Not shown here:
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# - 'TOKEN' stands for any token (leaf node)
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# - 'any' stands for any node (leaf or interior)
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# With 'any' we can still specify the sub-structure.
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# The start symbol is 'Matcher'.
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Matcher: Alternatives ENDMARKER
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Alternatives: Alternative ('|' Alternative)*
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Alternative: (Unit | NegatedUnit)+
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Unit: [NAME '='] ( STRING [Repeater]
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| NAME [Details] [Repeater]
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| '(' Alternatives ')' [Repeater]
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| '[' Alternatives ']'
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)
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NegatedUnit: 'not' (STRING | NAME [Details] | '(' Alternatives ')')
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Repeater: '*' | '+' | '{' NUMBER [',' NUMBER] '}'
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Details: '<' Alternatives '>'
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