That's "SMILES". Yes. Here is the yacc grammar for the SMILES parser in the RDKit. https://github.com/rdkit/rdkit/blob/master/Code/GraphMol/SmilesParse/smiles.

That's "SMILES". Yes. Here is the yacc grammar for the SMILES parser in the RDKit. https://github.com/rdkit/rdkit/blob/master/Code/GraphMol/SmilesParse/smiles.yy https://github.com/rdkit/rdkit/blob/master/Code/GraphMol/Smi... There's also one from OpenSMILES at http://opensmiles.org/opensmiles.html#_grammar http://opensmiles.org/opensmiles.html#_grammar . It has a shift/reduce error (as I recall) that I was not competent enough to fix. I prefer to parser almost completely in the lexer, with a small amount of lexer state to handle balanced parens, bracket atoms, and matching ring closures. See https://hg.sr.ht/~dalke/opensmiles-ragel https://hg.sr.ht/~dalke/opensmiles-ragel and more specifically https://hg.sr.ht/~dalke/opensmiles-ragel/browse/opensmiles.rl?rev=tip https://hg.sr.ht/~dalke/opensmiles-ragel/browse/opensmiles.r... .