NARS2000

Transcribed from the printed issue; not yet reviewed.

NARS 2000¶

The Next Major Release¶

Bob Smith, Sudley Place Software, 24 March 2012

Begun in September 2006, NARS2000 remains the only full-featured Extended APL Standard compliant free open source APL interpreter still in active development. As an experimental APL interpreter, it contains a host of old, new, and borrowed ideas including these features from the past year:

• Language bar: All APL chars in easy view – no more fumbling with Ctrl- or Alt-key combinations.
• User-defined keyboard layouts: Change the keyboard to exactly where you expect the APL and non-APL characters to be.
• Multiset operator: f⍦ R and L f⍦ R applies various primitive and user defined functions to vectors treating them as Multisets – sets with repeated elements.
• Root primitive: √R and N√R – square root and Nth root.
• Number factoring and number-theoretic fns: πR and LπR – factors numbers, tests for prime, finds Nth prime, number of primes≤N, etc.
• Support for Rational and VFP numbers:
  123x, 2r3, and 2v3 – Find the low-order ten digits of the sum of N to the Nth for N from
  1 to 1000 – ¯10↑⍕+/*⍨⍳1000x ↔ 9110846700
• Sequence function:
  L..R – ¯2..8 ↔ ¯2 ¯1 0 1 2 3 4 5 6 7 8
• Native File functions: ⎕NCREATE, ⎕NTIE, etc.

NARS2000 runs on several platforms: 32- or 64-bit Windows XP and later, along with any OS that can run Wine (a translation – not emulation – layer) available on almost all Linux systems.

Download either the 32- or 64-bit version from the website mentioned below. It's free – no forms to fill in, no permissions needed, and it comes with its own APL font or you can use an existing APL Unicode font.

If you like the idea of having an open source interpreter, please look for ways to help:

• Promote it: tell your friends and demo it to them.
• Test it: migrate your favourite code via .atf files or Copy & Paste Unicode characters; write test cases for various primitive functions.
• Document it: add to the Wiki.
• Develop it: write APL or C code to add new features or improve old ones – some new and old primitives have been implemented in APL using the language as a rapid prototyping tool and can be recoded in C if and when performance is a concern.