An LR substring parser for noncorrecting syntax error recovery

For a context-free grammar <italic>G</italic>, a construction is given to produce an LR parser that recognizes any substring of the language generated by <italic>G</italic>. The construction yields a conflict-free (deterministic) parser for the <italic>bounded context</italic> class of grammars (Floyd, 1964). The same construction yields either a left-to-right or right-to-left substring parser, as required to implement <italic>Non-correcting Syntax Error Recovery</italic> as proposed by Richter (1985). Experience in constructing a substring parser for Pascal is described.