Linter reference

The AsciiChem linter is a separate opt-in pass that walks the model and reports chemistry errors. It does not modify the model.

Running

formula = AsciiChem.parse("H_2 + O_2 -> H_2O")
diagnostics = AsciiChem::Linter.run(formula)
diagnostics.each { |d| puts d }

Or via CLI:

asciichem lint -i "H_2 + O_2 -> H_2O"
asciichem lint -i "..." -f json

Built-in checks

Check	Severity	What it validates
BalanceCheck	error	Stoichiometric atom conservation in reactions
ChargeBalanceCheck	error	Charge conservation in reactions (v0.7+)
BracketBalanceCheck	error	Group bracket consistency
CrystalSanityCheck	error	Cell lengths positive, angles in (0, 180], fractional coords in [0, 1)
ZMatrixReferenceCheck	error	References point to earlier rows; distances positive
SpectrumPeakCheck	warning	Peak positions and intensities are numeric
ElementValidationCheck	warning	Element symbols in the periodic table
IsotopeSanityCheck	warning	Isotope mass ≥ atomic number
UnclosedRingCheck	error	Ring closure digits have matching pairs
ValenceCheck	error	Bond order + charge ≤ max valence
IdentifierFormatCheck	error	@cas/@inchi/@inchikey/@smiles values parse offline (check digits, layer structure)
IdentifierConsistencyCheck	error/warning	Identifier values agree with the molecule they annotate (InChI formula layer, SMILES element set)
IdentityCrossCheck	error/warning	Derives the structure’s InChI via the configured engine and compares against @inchi/@inchikey annotations; mismatch = error, absent engine = one guidance warning

Diagnostic object

diagnostic.severity  # => :error, :warning, or :info
diagnostic.message   # => "Reaction is not balanced: H: 2 vs 4"
diagnostic.node       # => the Model::Node that triggered it

Adding a custom check

class MyCheck < AsciiChem::Linter::Base
  register :my_check

  def run(formula)
    diagnostics = []
    walk(formula) do |node|
      # check each node...
    end
    diagnostics
  end
end

Self-registers at file-load time via Linter::Base.register.