feel

An interpreter for the FEEL - Friendly Enough Expression Language, written in Go(lang). FEEL is broadly used in DMN and BPMN to provide rule engine and script support. The feel module can be imported into other Go projects or used as command line executable.

Credits

This library is based on work of @superisaac/FEEL.go and many thanks and credits go to him.

Build

• run make build to build feel interpreter bin/feel
• run make test to run testing

Use in golang applications

import (
  feel "github.com/pbinitiative/feel"
)

res, err := feel.EvalString("5 + 7")

Examples, with using the CLI tool

% bin/feel -c '"hello " + "world"'
"hello world"

% bin/feel -c '(function(a, b) a + b)(5, 8)'
13

# dump AST tree instead of evaluating the script
% bin/feel -c 'bind("a", 5); if a > 3 then "larger" else "smaller"' -ast
(explist (call bind ["a", 5]) (if (> a 3) "larger"  "smaller"))

% bin/feel -c 'some x in [3, 4, 8, 9] satisfies x % 2 = 0'
4

% bin/feel -c 'every x in [3, 4, 8, 9] satisfies x % 2 = 0'
[
  4,
  8
]