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Diane’s Lasagne Problem

Making Lasagne Participants in the SA2 Performance Tuning workshop at the Dyalog ’18 User Meeting were encouraged to bring their own problems for the group… Read

Permuting Internal Letters

Friday Afternoon It’s something of a custom in Dyalog to send a “fun” e-mail to the group on Friday afternoons. My gambit for this past… Read

50847534

⎕io←0 throughout. I was re-reading A Mathematician’s Apology before recommending it to Suki Tekverk, our summer intern, and came across a statement… Read

Constructions

Suki Tekverk, a summer intern, spent the last two weeks here studying APL. She will be a high school senior next September and is adept in math, so in addition… Read

The Story of a Summer Intern

by Suki Tekverk As a born and raised New Yorker, I thought I had seen it all, but two short weeks spent in Vancouver with Roger Hui and his family proved me… Read

Loops, Folds and Tuples

For-loops Given an initial state defined by a number of variables, a for-loop iterates through its argument array modifying the state.     A←... ⋄… Read

Type Comments

I’ve taken to commenting the closing brace of my inner dfns with a home-grown type notation pinched from the Functional Programming community: dref←{… Read

Response to Name Colouring for Dfns

This post contains comments to John Scholes’ post on name colouring; please continue to post any further comments with the original post. This is a very… Read

Name Colouring for Dfns

APL is sometimes criticised because expressions that include names cannot, in general, be parsed without knowing whether the names represent functions or… Read

Do Functions Know Their Own Names?

Going back a long way when John Scholes and I were writing version 0 of Dyalog there was a big discussion about whether functions knew their own names. This… Read

Unforgettable Numbers

Professor Kip Murray asked on the J Forum for the “unforgettable” times seen on a 24-hour digital clock. The problem is that every number has… Read

Foo, Shmoo

“We do not realize what tremendous power the structure of an habitual language has. It is not an exaggeration to say that it enslaves us through the… Read

What’s Your Favourite Beautiful Squiggle?

Roger’s post speculating on Ken Iverson’s favourite APL expression reminded me that one of the delegates at Dyalog ’14 conducted a quick… Read

Ken Iverson’s Favourite APL Expression?

What was Ken Iverson’s favourite APL expression? I don’t know that he had one and if he had I don’t know what it was, but if I have to guess …… Read

Musings on Reduction

In one man’s humble opinion, reduction (⌿) is the Queen of Operators. Each (¨) comes a close second, but doesn’t get the cigar because each can… Read
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Technical advice and assistance on all aspects of Dyalog usage is available by e-mail (support@dyalog.com) and/or telephone (+44 1256 830030 – limited to U.K. office hours). Limited advice on design and coding is available, but is not intended to replace the use of the printed and on-line documentation. Except when reporting an issue with the software, users are encouraged to seek advice from the user community via the Dyalog Forum (reading the content of the forums does not require membership).

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