Control structure

Some modern versions of APL include a set of keywords for controlling flow of execution. Such keywords allow programmers to create control structures which are commonly used in procedural programming languages.

Example
Dyalog APL has a rich set of flow control keywords, including,  ,  ,   (with the supplementary control words   and  ),  ,  ,  ,   and. The use of control structures defined by these keywords is only allowed in defined functions.

For example, a function implementing the Trabb Pardo–Knuth algorithm using control structures:

Tutorials

 * APL Cultivation: Control structures
 * Bernard Legrand. Mastering Dyalog APL (page 189). Dyalog Ltd. November 2009.

Documentation

 * Dyalog
 * APLX