1# Ctype in Picolibc 2 3The Ctype family of functions provide a convenient way to process 4character data. The traditional implementation of these is to build a 5table of per-character classification data and have the individual 6functions index the table and extract the relevant data. This is quite 7efficient in code space and time for each indivdual test, but the 8table introduces a fairly large fixed cost. 9 10Picolibc provides an alternate implementation, selectable when 11compiling files using the API, where each function directly implements 12the necessary comparison operations. These are implemented as inline 13functions. In many cases, the resulting code is no larger than the 14table indexing operations and without the overhead of the table. 15 16When building with the 'optimize for size' option enabled (-Os), the 17new direct implementation is selected by default. You can also force a 18particular mode by defining `_PICOLIBC_CTYPE_SMALL` to `1` (select 19direct implementation) or `0` (select array-based implementation). 20
