2c5b9fb8f9
This patch adds String.prototype.charAt() to demonstrate that prototype property lookup works, and that you can call a prototype function on an object, and it will do what you expect. :^)
57 lines
2.4 KiB
C++
57 lines
2.4 KiB
C++
/*
|
|
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this
|
|
* list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <AK/Function.h>
|
|
#include <LibJS/Heap.h>
|
|
#include <LibJS/Interpreter.h>
|
|
#include <LibJS/PrimitiveString.h>
|
|
#include <LibJS/StringObject.h>
|
|
#include <LibJS/StringPrototype.h>
|
|
#include <LibJS/Value.h>
|
|
|
|
namespace JS {
|
|
|
|
StringPrototype::StringPrototype()
|
|
{
|
|
put_native_function("charAt", [](Interpreter& interpreter, Vector<Value> arguments) -> Value {
|
|
i32 index = 0;
|
|
if (!arguments.is_empty())
|
|
index = arguments[0].to_i32();
|
|
Value this_value = interpreter.this_value();
|
|
ASSERT(this_value.is_object());
|
|
ASSERT(this_value.as_object()->is_string_object());
|
|
auto underlying_string = static_cast<const StringObject*>(this_value.as_object())->primitive_string()->string();
|
|
if (index < 0 || index >= static_cast<i32>(underlying_string.length()))
|
|
return js_string(interpreter.heap(), String::empty());
|
|
return js_string(interpreter.heap(), underlying_string.substring(index, 1));
|
|
});
|
|
}
|
|
|
|
StringPrototype::~StringPrototype()
|
|
{
|
|
}
|
|
|
|
}
|