GraSs: A Taxonomy of Grammar Smells

Organisation
global problems

Navigation
problems with navigating through the grammar

Structure
harmful relationships among grammar components

Spaghetti
scattering details over the grammar

Shortage
incompleteness

Mixture
spicing the grammar with alien fragments

Uncluster
related nonterminals too far from one another

Unsequence
confusing order of the production rules

StartInTheMiddle
the root symbol should not occur in the middle

StartInTheMiddle Edit!

To improve the readability and navigability of the grammar, its starting symbol should be on top or the bottom of the grammar, not lost somewhere in the middle.

The GraSs taxonomy is a joint effort maintained by Dr. Vadim Zaytsev a.k.a. @grammarware. Page last updated in March 2021.