mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2025-10-31 13:20:59 +00:00
f5476be702
I always tell people to start building things by working on the thing that seems the most interesting right now. The most interesting thing here was an AST + simple interpreter, so that's where we start! There is no lexer or parser yet, we build an AST directly and then execute it in the interpreter, producing a return value. This seems like the start of something interesting. :^)
144 lines
3.9 KiB
C++
144 lines
3.9 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 <LibJS/AST.h>
|
|
#include <LibJS/Function.h>
|
|
#include <LibJS/Interpreter.h>
|
|
#include <LibJS/Value.h>
|
|
#include <stdio.h>
|
|
|
|
namespace JS {
|
|
|
|
Value ScopeNode::execute(Interpreter& interpreter) const
|
|
{
|
|
return interpreter.run(*this);
|
|
}
|
|
|
|
Value FunctionDeclaration::execute(Interpreter& interpreter) const
|
|
{
|
|
auto* function = new Function(name(), body());
|
|
interpreter.global_object().put(m_name, Value(function));
|
|
return Value(function);
|
|
}
|
|
|
|
Value CallExpression::execute(Interpreter& interpreter) const
|
|
{
|
|
auto callee = interpreter.global_object().get(name());
|
|
ASSERT(callee.is_object());
|
|
auto* callee_object = callee.as_object();
|
|
ASSERT(callee_object->is_function());
|
|
auto& function = static_cast<Function&>(*callee_object);
|
|
return interpreter.run(function.body());
|
|
}
|
|
|
|
Value ReturnStatement::execute(Interpreter& interpreter) const
|
|
{
|
|
auto value = argument().execute(interpreter);
|
|
interpreter.do_return();
|
|
return value;
|
|
}
|
|
|
|
Value add(Value lhs, Value rhs)
|
|
{
|
|
ASSERT(lhs.is_number());
|
|
ASSERT(rhs.is_number());
|
|
return Value(lhs.as_double() + rhs.as_double());
|
|
}
|
|
|
|
Value sub(Value lhs, Value rhs)
|
|
{
|
|
ASSERT(lhs.is_number());
|
|
ASSERT(rhs.is_number());
|
|
return Value(lhs.as_double() - rhs.as_double());
|
|
}
|
|
|
|
Value BinaryExpression::execute(Interpreter& interpreter) const
|
|
{
|
|
auto lhs_result = m_lhs->execute(interpreter);
|
|
auto rhs_result = m_rhs->execute(interpreter);
|
|
|
|
switch (m_op) {
|
|
case BinaryOp::Plus:
|
|
return add(lhs_result, rhs_result);
|
|
case BinaryOp::Minus:
|
|
return sub(lhs_result, rhs_result);
|
|
}
|
|
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
|
|
static void print_indent(int indent)
|
|
{
|
|
for (int i = 0; i < indent * 2; ++i)
|
|
putchar(' ');
|
|
}
|
|
|
|
void ASTNode::dump(int indent) const
|
|
{
|
|
print_indent(indent);
|
|
printf("%s\n", class_name());
|
|
}
|
|
|
|
void ScopeNode::dump(int indent) const
|
|
{
|
|
ASTNode::dump(indent);
|
|
for (auto& child : children())
|
|
child.dump(indent + 1);
|
|
}
|
|
|
|
void BinaryExpression::dump(int indent) const
|
|
{
|
|
ASTNode::dump(indent);
|
|
m_lhs->dump(indent + 1);
|
|
m_rhs->dump(indent + 1);
|
|
}
|
|
|
|
void CallExpression::dump(int indent) const
|
|
{
|
|
print_indent(indent);
|
|
printf("%s '%s'\n", class_name(), name().characters());
|
|
}
|
|
|
|
void Literal::dump(int indent) const
|
|
{
|
|
print_indent(indent);
|
|
printf("%d\n", (i32)m_value.as_double());
|
|
}
|
|
|
|
void FunctionDeclaration::dump(int indent) const
|
|
{
|
|
print_indent(indent);
|
|
printf("%s '%s'\n", class_name(), name().characters());
|
|
body().dump(indent + 1);
|
|
}
|
|
|
|
void ReturnStatement::dump(int indent) const
|
|
{
|
|
ASTNode::dump(indent);
|
|
argument().dump(indent + 1);
|
|
}
|
|
|
|
}
|