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LibJS: Start building a JavaScript engine for SerenityOS :^) 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. :^)
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/*
* 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/NonnullOwnPtr.h>
#include <LibJS/AST.h>
#include <LibJS/Interpreter.h>
#include <LibJS/Object.h>
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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#include <LibJS/Parser.h>
LibJS: Support "hello friends".length The above snippet is a MemberExpression that necessitates the implicit construction of a StringObject wrapper around a PrimitiveString. We then do a property lookup (a "get") on the StringObject, where we find the "length" property. This is pretty neat! :^)
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#include <LibJS/PrimitiveString.h>
LibJS: Start building a JavaScript engine for SerenityOS :^) 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. :^)
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#include <LibJS/Value.h>
#include <stdio.h>
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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#define PROGRAM 6
js: Make it a little easier to add new AST builder functions
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LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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static NonnullOwnPtr<JS::Program> build_program(JS::Heap&);
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
2020-03-09 21:13:55 +01:00
LibJS: Start building a JavaScript engine for SerenityOS :^) 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. :^)
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int main()
{
LibJS: Support "hello friends".length The above snippet is a MemberExpression that necessitates the implicit construction of a StringObject wrapper around a PrimitiveString. We then do a property lookup (a "get") on the StringObject, where we find the "length" property. This is pretty neat! :^)
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JS::Interpreter interpreter;
LibJS: Start building a JavaScript engine for SerenityOS :^) 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. :^)
2020-03-07 19:42:11 +01:00
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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auto program = build_program(interpreter.heap());
LibJS: Start building a JavaScript engine for SerenityOS :^) 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. :^)
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program->dump(0);
auto result = interpreter.run(*program);
dbg() << "Interpreter returned " << result;
printf("%s\n", result.to_string().characters());
js: Exercise the garbage collector a little bit
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js: Add another little test AST to exercise marking of locals
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dbg() << "Collecting garbage on exit...";
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interpreter.heap().collect_garbage();
LibJS: Start building a JavaScript engine for SerenityOS :^) 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. :^)
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return 0;
}
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
2020-03-09 21:13:55 +01:00
js: Make it a little easier to add new AST builder functions
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#if PROGRAM == 1
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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NonnullOwnPtr<JS::Program> build_program(JS::Heap&)
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
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{
// function foo() { return (1 + 2) + 3; }
// foo();
auto block = make<JS::BlockStatement>();
block->append<JS::ReturnStatement>(
make<JS::BinaryExpression>(
JS::BinaryOp::Plus,
make<JS::BinaryExpression>(
JS::BinaryOp::Plus,
make<JS::Literal>(JS::Value(1)),
make<JS::Literal>(JS::Value(2))),
make<JS::Literal>(JS::Value(3))));
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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auto program = make<JS::Program>();
program->append<JS::FunctionDeclaration>("foo", move(block));
program->append<JS::ExpressionStatement>(make<JS::CallExpression>("foo"));
return program;
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
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}
js: Make it a little easier to add new AST builder functions
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#elif PROGRAM == 2
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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NonnullOwnPtr<JS::Program> build_program(JS::Heap&)
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
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{
// c = 1;
// function foo() {
// var a = 5;
// var b = 7;
// return a + b + c;
// }
// foo();
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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auto program = make<JS::Program>();
program->append<JS::ExpressionStatement>(make<JS::AssignmentExpression>(
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
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JS::AssignmentOp::Assign,
make<JS::Identifier>("c"),
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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make<JS::Literal>(JS::Value(1))));
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
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auto block = make<JS::BlockStatement>();
block->append<JS::VariableDeclaration>(
make<JS::Identifier>("a"),
LibJS: Allow the choice of a scope of declaration for a variable (#1408) Previously, we were assuming all declared variables were bound to a block scope, now, with the addition of declaration types, we can bind a variable to a block scope using `let`, or a function scope (the scope of the inner-most enclosing function of a `var` declaration) using `var`.
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make<JS::Literal>(JS::Value(5)),
JS::DeclarationType::Var);
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
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block->append<JS::VariableDeclaration>(
make<JS::Identifier>("b"),
LibJS: Allow the choice of a scope of declaration for a variable (#1408) Previously, we were assuming all declared variables were bound to a block scope, now, with the addition of declaration types, we can bind a variable to a block scope using `let`, or a function scope (the scope of the inner-most enclosing function of a `var` declaration) using `var`.
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make<JS::Literal>(JS::Value(7)),
JS::DeclarationType::Var);
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
2020-03-09 21:13:55 +01:00
block->append<JS::ReturnStatement>(
make<JS::BinaryExpression>(
JS::BinaryOp::Plus,
make<JS::BinaryExpression>(
JS::BinaryOp::Plus,
make<JS::Identifier>("a"),
make<JS::Identifier>("b")),
make<JS::Identifier>("c")));
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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program->append<JS::FunctionDeclaration>("foo", move(block));
program->append<JS::ExpressionStatement>(make<JS::CallExpression>("foo"));
return program;
LibJS: Add basic support for (scoped) variables It's now possible to assign expressions to variables. The variables are put into the current scope of the interpreter. Variable lookup follows the scope chain, ending in the global object.
2020-03-09 21:13:55 +01:00
}
js: Make it a little easier to add new AST builder functions
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#elif PROGRAM == 3
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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NonnullOwnPtr<JS::Program> build_program(JS::Heap&)
js: Add another little test AST to exercise marking of locals
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{
// function foo() {
// var x = {};
// $gc();
// }
// foo();
auto block = make<JS::BlockStatement>();
block->append<JS::VariableDeclaration>(
make<JS::Identifier>("x"),
LibJS: Allow the choice of a scope of declaration for a variable (#1408) Previously, we were assuming all declared variables were bound to a block scope, now, with the addition of declaration types, we can bind a variable to a block scope using `let`, or a function scope (the scope of the inner-most enclosing function of a `var` declaration) using `var`.
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make<JS::ObjectExpression>(),
JS::DeclarationType::Var);
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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block->append<JS::ExpressionStatement>(make<JS::CallExpression>("$gc"));
js: Add another little test AST to exercise marking of locals
2020-03-09 21:30:12 +01:00
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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auto program = make<JS::Program>();
program->append<JS::FunctionDeclaration>("foo", move(block));
program->append<JS::ExpressionStatement>(make<JS::CallExpression>("foo"));
return program;
js: Add another little test AST to exercise marking of locals
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}
LibJS: Support "hello friends".length The above snippet is a MemberExpression that necessitates the implicit construction of a StringObject wrapper around a PrimitiveString. We then do a property lookup (a "get") on the StringObject, where we find the "length" property. This is pretty neat! :^)
2020-03-11 18:58:19 +01:00
#elif PROGRAM == 4
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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NonnullOwnPtr<JS::Program> build_program(JS::Heap&)
LibJS: Allow the choice of a scope of declaration for a variable (#1408) Previously, we were assuming all declared variables were bound to a block scope, now, with the addition of declaration types, we can bind a variable to a block scope using `let`, or a function scope (the scope of the inner-most enclosing function of a `var` declaration) using `var`.
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{
// function foo() {
// function bar() {
// var y = 6;
// }
//
// bar()
// return y;
// }
// foo(); //I should return `undefined` because y is bound to the inner-most enclosing function, i.e the nested one (bar()), therefore, it's undefined in the scope of foo()
auto block_bar = make<JS::BlockStatement>();
block_bar->append<JS::VariableDeclaration>(make<JS::Identifier>("y"), make<JS::Literal>(JS::Value(6)), JS::DeclarationType::Var);
auto block_foo = make<JS::BlockStatement>();
block_foo->append<JS::FunctionDeclaration>("bar", move(block_bar));
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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block_foo->append<JS::ExpressionStatement>(make<JS::CallExpression>("bar"));
LibJS: Allow the choice of a scope of declaration for a variable (#1408) Previously, we were assuming all declared variables were bound to a block scope, now, with the addition of declaration types, we can bind a variable to a block scope using `let`, or a function scope (the scope of the inner-most enclosing function of a `var` declaration) using `var`.
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block_foo->append<JS::ReturnStatement>(make<JS::Identifier>("y"));
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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auto program = make<JS::Program>();
program->append<JS::FunctionDeclaration>("foo", move(block_foo));
program->append<JS::ExpressionStatement>(make<JS::CallExpression>("foo"));
return program;
LibJS: Allow the choice of a scope of declaration for a variable (#1408) Previously, we were assuming all declared variables were bound to a block scope, now, with the addition of declaration types, we can bind a variable to a block scope using `let`, or a function scope (the scope of the inner-most enclosing function of a `var` declaration) using `var`.
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}
#elif PROGRAM == 5
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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NonnullOwnPtr<JS::Program> build_program(JS::Heap& heap)
LibJS: Support "hello friends".length The above snippet is a MemberExpression that necessitates the implicit construction of a StringObject wrapper around a PrimitiveString. We then do a property lookup (a "get") on the StringObject, where we find the "length" property. This is pretty neat! :^)
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{
// "hello friends".length
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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auto program = make<JS::Program>();
program->append<JS::ExpressionStatement>(make<JS::MemberExpression>(
LibJS: Support "hello friends".length The above snippet is a MemberExpression that necessitates the implicit construction of a StringObject wrapper around a PrimitiveString. We then do a property lookup (a "get") on the StringObject, where we find the "length" property. This is pretty neat! :^)
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make<JS::Literal>(JS::Value(js_string(heap, "hello friends"))),
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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make<JS::Identifier>("length")));
return program;
}
#elif PROGRAM == 6
NonnullOwnPtr<JS::Program> build_program(JS::Heap&)
{
const char* source = "var foo = 1;\n"
"function bar() {\n"
" return 38;\n"
"}\n"
"foo = {};\n"
"foo = bar() + 4;\n"
"foo;\n";
auto parser = JS::Parser(JS::Lexer(source));
return parser.parse_program();
LibJS: Support "hello friends".length The above snippet is a MemberExpression that necessitates the implicit construction of a StringObject wrapper around a PrimitiveString. We then do a property lookup (a "get") on the StringObject, where we find the "length" property. This is pretty neat! :^)
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}
js: Make it a little easier to add new AST builder functions
2020-03-09 21:58:27 +01:00
#endif
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