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parsingcompiler-constructionlr-grammar

LR(1) parser online verification

I'm currently studying LR parsing and in need of an online LR(1) parser to be able to verify my outcome. I've already stumbled upon this(LL(1)), where I was able to verify my first and follow set but I also want to verify my parsing diagram.

Could anyone provide me with a link of such a tool?

For completeness; I need to verify the following grammar:

S -> A a
S -> b A c
S -> d c
S -> b d a
A -> d
Solution

  • https://gist.github.com/rns/176632ab5b2652900871 -- not exactly online, this test script has arguably more features -- warns of inaccessible symbols, handles ambiguity and parses any BNF you can write. Hope it helps. You will need Perl and Marpa::R2, which provides general BNF parsing. Hope this helps.