Build tools to process tokens from an input stream
Description
The tokcycle package helps one to build tools to process tokens
from an input stream. If a macro to process an arbitrary single
token can be built, then tokcycle can provide a wrapper for
cycling through an input stream (including macros, spaces, and
groups) on a token-by-token basis, using the provided macro on
each successive character. tokcycle characterizes each
successive token in the input stream as a Character, a Group, a
Macro, or a Space. Each of these token categories are processed
with a unique directive, to bring about the desired effect of
the token cycle. If condition flags are provided to identify
active, implicit, and catcode-6 tokens as they are digested.
The package provides a number of options for handling groups.
