$ZATRANSFORM(expr,intexpr[,{0|1|2|-2}][,{0|1}])
Please see a??$ZCOLlate()a?? for a similar alternative.
The 2 and -2 work in M mode for the 'M' collation (collation 0), or any user defined collation which supplies the necessary plugin functionality. In UTF-8 mode, these argument values produce a ZATRANSCOL error. If the plugin for the specified collation does not support this "next character" functionality, the function produces a COLLATIONUNDEF error in response to an an attempt to invoke it. If an external collation library is used and encounters a gtm_ac_xutil failure, ZATRANSFORM produces an ERR_ZATRANSCOL. If an external collation library is used and does not supply a gtm_ac_xutil function, ZATRANSFORM produces an ERR_COLLATIONUNDEF when operations -2 or 2 are specified. To use these operations with external collation libraries, the libraries must supply a function called 'gtm_ac_xutil'. For more information on the following signature and characteristics of the gtm_ac_xutil function, refer to a??Transform Utility Routine (gtm_ac_xutil)a??.