Online demo

This tool checks whether the given text is syntactically correct according to the given grammar and that the grammar itself is syntactically correct. It can also analyze the grammar for ambiguity using the technique described in Analyzing Ambiguity of Context-Free Grammars, by Claus Brabrand, Robert Giegerich, and Anders Møller.

See also the description of the grammar notation and the example grammars.

Resources are limited for this web application - you can also download the tool and run it on your own machine.

Input files:

Upload grammar file:
...or enter a URL for the grammar:
...or enter the grammar here:
...or pick an example grammar:
Character encoding of grammar:
Unfold command (for ambiguity analysis):	level: left parentheses: right parentheses:

Upload text file (optional):
...or enter a URL for the text:
...or enter the text here:
Character encoding of text:

Options:

Only perform grammar check
Parse text
Analyze the grammar for potential ambiguity

Verbose, print progress information and statistics
Tokenize grammar before ambiguity analysis

dk.brics.grammar

Online demo

Input files:

Options: