REXX expressions can be used in FORM.CALC, FORM.CONDITIONS and FORM.COLUMNS (Column Definition). A valid REXX expression that can be reduced to a 0 or 1. Typically contains a REXX comparative operator. The @IF function tests the comparison and if the result is 1, the expression following the function is evaluated and the results are returned.

REXX provides a rich set of built-in functions, including character manipulation, conversion, and information functions. There are six other built-in functions that TSO/E provides: EXTERNALS, FIND, INDEX, JUSTIFY, LINESIZE, and USERID.

There are two types of conditional instructions. IF/THEN/ELSE can direct the execution of an exec to one of two choices. SELECT/WHEN/OTHERWISE/END can direct the execution to one of many choices. instruction. When you put the entire instruction on one line, you must separate the THEN clause from the ELSE clause with a semi-colon.

REXX expressions consist of one or more terms interspersed with zero or more operators that denote operations to be carried out on terms. Expressions are evaluated left to right, modified by parentheses and by operator precedence in the usual algebraic manner.

There are two types of looping instructions, repetitive loops and conditional loops. Repetitive loops allow you to repeat instructions a certain number of times, and conditional loops use a condition to control repeating. All loops, regardless of the type, begin with …

Obviously, the resulting string must be a value that is expected or required by the function, or an error could occur. A powerful feature of REXX is that multiple functions can be combined or nested to produce a result. The above examples of expressions used in a function would yield the same result. 6/32

t i o n s This appendix provides a reference to all Rexx functions, as defined by the ANSI-1996. standard. It also points out the important differences between the ANSI-1996 standard and the earlier standard defined.

This Rexx tutorial will be helpful for Mainframe application program / Mainframe system programmer, to make them comfortable in getting started with (Rexx) Restructured Extended Executor and its various functions.

2015年9月24日 · REXX interpreter Brought to you by: erich_st, orexx, perolovjonsson, rvjansen, sahananda Summary Files Reviews Support Wiki

The REXX language is a versatile general-purpose programming language that can be used by new and experienced programmers. This part of the book is for programmers who want to learn the REXX language.