instance method · added in Ruby 4.0

Binding#implicit_parameter_get

binding.implicit_parameter_get(symbol) → obj

static VALUE
bind_implicit_parameter_get(VALUE bindval, VALUE sym)
{
    ID lid = check_local_id(bindval, &sym);
    const rb_binding_t *bind;
    const VALUE *ptr;
    const rb_env_t *env;

    if (lid == idIt) lid = idItImplicit;

    if (!lid || !rb_implicit_param_p(lid)) {
        rb_name_err_raise("'%1$s' is not an implicit parameter",
                          bindval, sym);
    }

    GetBindingPtr(bindval, bind);

    env = VM_ENV_ENVVAL_PTR(vm_block_ep(&bind->block));
    if ((ptr = get_local_variable_ptr(&env, lid, FALSE)) != NULL) {
        return *ptr;
    }

    if (lid == idItImplicit) lid = idIt;
    rb_name_err_raise("implicit parameter '%1$s' is not defined for %2$s", bindval, ID2SYM(lid));
    UNREACHABLE_RETURN(Qundef);
}

Returns the value of the numbered parameter or “it” parameter.

Example

def foo
  [42].each do
    it
    binding.implicit_parameter_get(:it) #=> 42
  end

  { k: 42 }.each do
    _2
    binding.implicit_parameter_get(:_1) #=> :k
    binding.implicit_parameter_get(:_2) #=> 42
  end
end

Ruby version changes

4.0
- Binding#implicit_parameters, Binding#implicit_parameter_get, and Binding#implicit_parameter_defined? have been added to access numbered parameters and “it” parameter. [Bug #21049]

See also #implicit_parameter_defined? #implicit_parameters #eval #local_variable_defined? also in 4.1

‹ prev#implicit_parameter_defined? next ›#implicit_parameters