COWSEL

COWSEL was initially implemented on a Ferranti Pegasus computer at the University of Leeds and on a Stantec Zebra at the Bradford Institute of Technology. Later, Rod Burstall implemented it on an Elliot 4120 at the University of Edinburgh.

COWSEL was renamed POP-1 in 1966, during summer, and development continued under that name from then on.

Example code

<u id="mwIQ">function</u> member <u id="mwIg">lambda</u> x y <u id="mwIw">comment</u> Is x a member of list y; <u id="mwJA">define</u> y <u id="mwJQ">atom</u> <u id="mwJg">then</u> *0 <u id="mwJw">end</u> y <u id="mwKA">hd</u> x <u id="mwKQ">equal</u> <u id="mwKg">then</u> *1 <u id="mwKw">end</u> y <u id="mwLA">tl</u> -> y <u id="mwLQ">repeat</u> <u id="mwLg">up</u>

Reserved words (keywords) were also underlined in the original printouts. Popplestone performed syntax highlighting by using underscoring on a Friden Flexowriter.