Expr (Go expression language) releases v1.11
Release v1.11.0 · expr-lang/expr
Expr – an expression language for Go.

This release introduces a new API for defining functions inside Expr - expr.Function.
From an Expr expression is already possible to call any Go methods and functions, but Expr has to use reflect package in doing such calls.
In previous releases, Expr added a special case for func (...any) any to avoid using reflect. But such functions lack type information. With newly added expr.Function option now it's possible to define a fast function with optional types! Read more in the docs.
atoi := expr.Function(
	"atoi",
	func(params ...any) (any, error) {
		return strconv.Atoi(params[0].(string))
	},
	new(func(string) int),
)

program, err := expr.Compile(`atoi("42")`, atoi)
Also in this release:

Added bool condition optimization.
Added support for comments // and /* ... */.
Added support for negative indexes list[-1].
Predicate brackets are now optional all(list, .values > 0).
Added int() and float() builtins.
Improved built-in functions performance.
