Editing APL (programming language) (section)

=== Idiom recognition ===
Most APL interpreters support [[Programming idiom|idiom]] recognition<ref>{{cite book |last1=Metzger |first1=Robert |last2=Wen |first2=Zhaofang |title=Automatic Algorithm Recognition and Replacement: A New Approach to Program Optimization |publisher=The MIT press |year=2000 |isbn=9780262133685 |url=https://books.google.com/books?id=u38h_fV3UqgC&pg=PA12 |access-date=May 6, 2018}}</ref> and evaluate common idioms as single operations.<ref>{{cite journal |last1=Snyder |first1=Lawrence |date=1982 |title=Recognition and Selection of Idioms for Code Optimization |journal=Acta Informatica |volume=17 |issue=3 |doi=10.1007/BF00264357 |s2cid=8369972}}</ref><ref>{{cite thesis |last1=Cheng |first1=Feng Sheng |date=1981 |title=Idiom matching: an optimization technique for an APL compiler |url=https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=7896&context=rtd |publisher=Iowa State University |access-date=May 6, 2018}}</ref> For example, by evaluating the idiom <code>BV/⍳⍴A</code> as a single operation (where <code>BV</code> is a Boolean vector and <code>A</code> is an array), the creation of two intermediate arrays is avoided.<ref>{{cite web |url=http://help.dyalog.com/16.0/Content/Language/Defined%20Functions%20and%20Operators/Idiom%20Recognition/Idiom%20Recognition.htm |title=Idiom Recognition |publisher=dyalog.com |access-date=May 6, 2018}}</ref>