Richard Smith - Development Manager

DYNA26: 27 April 2026. More info

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Richard Smth

Development Manager

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Richard is the Development Manager within the Dyalog interpreter development team. In this role he divides his time between working on the interpreter and planning and keeping track of the development projects. More about Richard

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Case Conversion: Mapping and Folding

Dyalog v18.0 introduced ⎕C, which converts the case of characters in an array by mapping to lower case, mapping to upper case, or folding. This superseded an earlier experimental I-beam (819⌶) that could map to lower or upper case but not fold – this I-beam is currently deprecated and will be removed in Dyalog v20.0. … Read

May 2024
in APL Language

I-Beam Mnemonics

I-Beam (⌶) is an operator that takes as its operand a numeric code and derives a function which isn’t really considered to be part of the APL language – for example: something which could be experimental, which might provide access to parts of the interpreter that should only be accessed with care, or may set … Read

Jun 2016
in APL Language, Tips & Tricks

Zero-length Regular Expression Matches Considered Harmful

I was asked by a colleague why ⎕S reports two matches in the following example: ('d*'⎕S 0 1)'321' ┌───┬───┐ │0 3│3 0│ └───┴───┘ Here we are asking for the position and length of sequences of zero or more digits in an input document containing three numeric characters. Intuitively there is just one match of all … Read