This program is a set of tools to check EBNF rules.
Note that this project uses a non standard syntax of EBNF that is taught in the course "Introduction to Programming" at ETH
- The first rule in a file is interpreted as the "top-level" rule of the grammar, i.e. the one you want to check words on. This is especially important when you want to compare two files - not necessarily the rules with the same name are compared.
- There are currently no warnings for using rules that aren't defined - This leads to (parts of) rules not recognizing any words if there is a typo.
To get an overview of all available commands, run
parsley help
To check for syntax errors in a file, use the subcommand parse.
# This should not contain any error
parsley parse rules/scream
# This should contain a wide range of syntax errors
parsley parse rules/errors
To check if a word is contained in a language described by some EBNF rules, use the subcommand check.
parsley check rules/scream 'a'
parsley check rules/scream 'aAaAaaAaa'
parsley check rules/scream 'foo'
To see if a whole list of words is contained in a language, use the subcommand check-file.
Note: the words need to be separated by a newline.
parsley check-file rules/scream rules/scream.test
To compare two grammars, and see if there are words that are accepted by one but not the other, use the subcommand compare.
There is an optional parameter to specify how many words to check.
parsley compare rules/scream rules/long-scream
To get a list of words that fit to a set of rules, use subcommand produce-words.
There is an optional argument to specify how many words.
parsley produce-words rules/scream
parsley produce-words rules/scream 50
There are a few different ways to install this software.
There is the possibility to download prebuilt binaries in the releases tab.
Alternatively you can install it by building it from source with
cargo install --git https://github.com/JM4ier/parsley
This requires an installed Rust compiler.