c0395c9ef6
* [build_ts_refs] improve caches, allow building a subset of projects * cleanup project def script and update refs in type check script * rename browser_bazel config to avoid kebab-case * remove execInProjects() helper * list references for tsconfig.types.json for api-extractor workload * disable composite features of tsconfig.types.json for api-extractor * set declaration: true to avoid weird debug error * fix jest tests Co-authored-by: spalger <spalger@users.noreply.github.com> |
||
---|---|---|
.. | ||
docs | ||
grammar | ||
src | ||
test | ||
babel.config.js | ||
BUILD.bazel | ||
index.d.ts | ||
jest.config.js | ||
package.json | ||
README.md | ||
tsconfig.json |
kbn-tinymath
kbn-tinymath is a tiny arithmetic and function evaluator for simple numbers and arrays. Named properties can be accessed from an optional scope parameter.
It's available as an expression function called math
in Canvas, and the grammar/AST structure is available
for use by Kibana plugins that want to use math.
See Function Documentation for details on built-in functions available in Tinymath.
const { evaluate } = require('@kbn/tinymath');
// Simple math
evaluate('10 + 20'); // 30
evaluate('round(3.141592)') // 3
// Named properties
evaluate('foo + 20', {foo: 5}); // 25
// Arrays
evaluate('bar + 20', {bar: [1, 2, 3]}); // [21, 22, 23]
evaluate('bar + baz', {bar: [1, 2, 3], baz: [4, 5, 6]}); // [5, 7, 9]
evaluate('multiply(bar, baz) / 10', {bar: [1, 2, 3], baz: [4, 5, 6]}); // [0.4, 1, 1.8]
Adding Functions
Functions can be injected, and built in function overwritten, via the 3rd argument to evaluate
:
const { evaluate } = require('@kbn/tinymath');
evaluate('plustwo(foo)', {foo: 5}, {
plustwo: function(a) {
return a + 2;
}
}); // 7
Parsing
You can get to the parsed AST by importing parse
const { parse } = require('@kbn/tinymath');
parse('1 + random()')
/*
{
"name": "add",
"args": [
1,
{
"name": "random",
"args": []
}
]
}
*/
Notes
- Floating point operations have the normal Javascript limitations
Building kbn-tinymath
This package is rebuilt when running yarn kbn bootstrap
, but can also be build directly
using yarn build
from the packages/kbn-tinymath
directory.
Running tests
To test @kbn/tinymath
from Kibana, run yarn run jest --watch packages/kbn-tinymath
from
the top level of Kibana.