assertmacro with informative reports on failure
define-opt: A concise definition form with optional arguments and default values
make-char-quotatorto Miscellaneous string utilities. String utility functions that have become part of SRFI-13 are moved to srfi-13-local.scm. The latter is a local, optimized implementation of a small subset of SRFI-13, for Scheme systems that do not offer SRFI-13 natively or conveniently.