Selective Expression Tracing
Operator trace from dfns.dws is a simple and low-tech tool for displaying intermediate results of functions, during the evaluation of an expression. For example, what’s going on here? (+⌿ ÷ ≢) 1 2 3 4 2.5 We can guess that the above fork is computing the average of the right argument. To see how this works: )copy dfns […]
Data-driven Conditionals
ACKNOWLEDGEMENT: My thanks to Andy Shiers for simplifying the examples Visitors to APL from other languages are sometimes a bit sniffy about our use of numbers (1 0) for Boolean values True and False. They’re further bemused by our fondness for moving conditional processing out of code and into data. For example, instead of: 0=2|⍵: […]
Why Dyalog ’14 was a Shear Delight
Recent versions of Microsoft Windows support touch screens, which of course means that applications can respond to events originating from touches. Microsoft calls these events “gestures”. Dyalog decided to add support for gestures to version 14.1 and so projects were planned, designs were designed, code was coded and, at Dyalog ’14 (#Dyalog14), a demonstration was […]
