K
K denotes a family of programming languages designed by Arthur Whitney and commercialized by Morgan Stanley, Kx Systems, and Shakti. In 1985, while at Morgan Stanley, Whitney created the statically typed A dialect of APL. His colleagues extended A into A+ in 1988. Finally, Whitney presented the first K implementation in 1992, a "reduced instruction set" dialect which only used ASCII glyphs and limited arrays to (nested) vectors. For a long time, K's main role was as implementation language for Q, the query language of kdb+, which is an in-memory, column-based database. K7 ("Shakti K") was the first K to have full Unicode support, and it also uses a limited set non-ASCII symbols in the core language, for example Ø and ∞.
Releases
See The Evolution of Database Software.
| Year | Version |
|---|---|
| 1992 | K0 |
| 1994 | K1 |
| 1996 | K2 |
| 2000 | K4 |
| unreleased | K5 |
| unreleased | K6 |
| 2018 | K7 (Shakti) |
| unreleased | K8 |
| 2020 | K9 (Shakti) |
Primitives
K3
From the Kona Wiki.
| Verb | Monadic | Dyadic | Triadic | Tetradic |
|---|---|---|---|---|
+ |
flip (Transpose) | plus | ||
- |
negate | minus | ||
* |
first | times | ||
% |
reciprocal | divide | ||
| |
reverse | max|or | ||
& |
where | min|and | ||
^ |
shape | power | ||
! |
enumerate (includes Iota) | rotate|mod | ||
< |
grade up | less than | ||
> |
grade down | greater than | ||
= |
group | equals | ||
~ |
not, attribute | match | ||
@ |
atom | at index | amend/trap | amend |
? |
range (Unique) | function inverse/find/draw/deal/sample | invert-guess | |
_ |
floor | drop|cut | ||
, |
enlist (like Enclose) | join | ||
# |
count | take|reshape | ||
$ |
format | dollar (conversions) | ||
. |
make/unmake dictionary | dot index | amend/trap | amend |
: |
colon | assignment |
| Adverb | Definition |
|---|---|
/ |
over (incudes Reduce and Power) |
\ |
scan |
' |
each |
/: |
each right |
\: |
each left |
': |
eachpair (like Windowed Reduce) |
External links
| APL dialects [edit] | |
|---|---|
| Maintained | APL+Win ∙ APL2 ∙ APL64 ∙ APL\iv ∙ Aplette ∙ April ∙ Co-dfns ∙ Dyalog APL ∙ Dyalog APL Vision ∙ dzaima/APL ∙ GNU APL ∙ Kap ∙ NARS2000 ∙ Pometo ∙ TinyAPL |
| Historical | A Programming Language ∙ A+ (A) ∙ APL# ∙ APL2C ∙ APL\360 ∙ APL/700 ∙ APL\1130 ∙ APL\3000 ∙ APL.68000 ∙ APL*PLUS ∙ APL.jl ∙ APL.SV ∙ APLX ∙ Extended Dyalog APL ∙ Iverson notation ∙ IVSYS/7090 ∙ NARS ∙ ngn/apl ∙ openAPL ∙ Operators and Functions ∙ PAT ∙ Rowan ∙ SAX ∙ SHARP APL ∙ Rationalized APL ∙ VisualAPL (APLNext) ∙ VS APL ∙ York APL |
| Derivatives | AHPL ∙ BQN ∙ CoSy ∙ ELI ∙ Glee ∙ I ∙ Ivy ∙ J ∙ Jelly ∙ K (Goal, Klong, Q) ∙ KamilaLisp ∙ Lang5 ∙ Lil ∙ Nial ∙ RAD ∙ Uiua |
| Overviews | Comparison of APL dialects ∙ Timeline of array languages ∙ Timeline of influential array languages ∙ Family tree of array languages |