I expect you are surprised by the performance possible by k9 and the fact that it all fits into a 134,152 bytes! (For comparison the ls program weighs in 51,888 bytes and can’t even change directory.)
If you’re frustrated by the syntax or terse errors, then you’re not alone. I’d expect most had the same problems, persevered, and finally came away a power user able to squeeze information from data faster than previously imagined.
If you’ve come along enough to get it, then you’ll probably realised this manual isn’t needed and it’s all here...
Universal database, webserver and language -- full stack -- fast
Database
select A by B from T where C; update A from T
count first last sum min max *[avg var dev med ..]
x,y / insert, upsert, union, equi+asof leftjoin
x+y / equi+asof outerjoin (e.g. combine markets through time)
x#y / take/intersect
x_y / drop/difference
Language
Verb Adverb Type System
: x y f/ over c/ +join bool 011b \l a.k
+ flip plus f\ scan c\ +split int 0N 0 2 3 \t:n x
- negate minus f' each v' +has flt 0n 0 2 3. \u:n x
* first times f': eachp v': +bin char " ab" \v
% divide f/: eachr ([n;]f)/: name ``ab \w
& where min/and f\: eachl ([n;]f)\: uuid \cd x
| reverse max/or
< asc less .z.[md] date 2001.01.01
> dsc more .z.[hrstuv] time 12:34:56.123456789
= group equal I/O
~ not match 0: r/w line Class \f
! enum key 1: r/w byte List (2;3.4;`a) \ft x
, enlist cat *2: r/w data Dict `i`f!(2;3.4) \fl x
^ sort [f]cut *3: k-ipc set Func {[a;b]a+b} \fc x
# count [f]take *4: https get Expr :a+b
_ floor [f]drop
$ string cast+ Table
? unique+ find+ $[b;x;y] if else t:[[]i:2 3;f:3 4.;s:`a`b]
@ type [f]at @[x;i;f[;y]] amend utable [[b:..]a:..]
. value [f]dot .[x;i;f[;y]] dmend xtable `..![[]a:..]
sqrt sqr exp log sin cos div mod bar .. freq rank msum .. in bin within ..
\\ exit / comment *[if do while select[a;b;t;c]]
Interface
`csv?`csv t / read/write csv
`json?`json t / read/write json
-python: import k;k.k('+',2,3)
-nodejs: require('k').k('+',2,3)
*ffi: "./a.so"5:`f!"i" /I f(I i){return 2+i;} //cblas ..
*c/k: "./b.so"5:`f!1 /K f(K x){return ki(2+xi);} //feeds ..
*enterprise[unlimited data/users/machines/..] +overload