Really (this time) no reduce/reduce conflicts in grammar #68
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JasonBarnabe
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Nov 29, 2015
Really (this time) no reduce/reduce conflicts in grammar
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Thanks! My method in updating the parser files is akin to wandering in the dark, hoping to bump into the correct solution. Glad to have someone who knows what they're doing fix stuff up. |
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Last time, when I converted the right recursion in
one_or_more_semisto left recursion, I accidentally introduced another R/R conflict! Sorry!In the diff below, you can see an adjustment involving
optional_space; this one caused a conflict because it can be null, andany_number_of_identscan also be null, so if there is a space but no "idents", the parser won't know if the space should be consumed by the first instance ofoptional_spaceor the second.Similarly with
one_or_more_semis-- there were several redundant rules fordeclarations, and if there were semis there, there was more than one way that the rules could be applied to parse them. Now there is only ever one way that thedeclarationsrules can be applied.(I'm just working on the 2.0 release of Racc, and have added much better warnings, which show you just where Racc has difficulty with your grammar. This is how I found these. There are still 3 S/R conflicts, which I may figure out how to fix later.)