Function Function

expr.go:152–171

Function adds function to list of functions what will be available in expressions.

(name string, fn func(params ...any) (any, error), types ...any)

// Function adds function to list of functions what will be available in expressions.
func Function(name string, fn func(params ...any) (any, error), types ...any) Option {
	return func(c *conf.Config) {
		ts := make([]reflect.Type, len(types))
		for i, t := range types {
			t := reflect.TypeOf(t)
			if t.Kind() == reflect.Ptr {
				t = t.Elem()
			}
			if t.Kind() != reflect.Func {
				panic(fmt.Sprintf("expr: type of %s is not a function", name))
			}
			ts[i] = t
		}
		c.Functions[name] = &builtin.Function{
			Name:  name,
			Func:  fn,
			Types: ts,
		}
	}
}

// DisableAllBuiltins disables all builtins.
func DisableAllBuiltins() Option {