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ladybird/Libraries/LibJS/AST.cpp

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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. :^)
2020-03-07 19:42:11 +01:00
/*
* 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.
*/
LibJS: Allow functions to take arguments (#1405)
2020-03-12 19:22:13 +08:00
#include <AK/HashMap.h>
#include <AK/StringBuilder.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/AST.h>
#include <LibJS/Interpreter.h>
LibJS: Defer Value construction until a Literal is executed Remove the need to construct a full Value during parsing. This means we don't have to worry about plumbing the heap into the parser. The Literal ASTNode now has a bunch of subclasses that synthesize a Value on demand.
2020-03-12 12:19:11 +01:00
#include <LibJS/PrimitiveString.h>
LibJS: Split Function into subclasses NativeFunction and ScriptFunction Both types of functions are now Function and implement calling via: virtual Value call(Interpreter&, Vector<Value> arguments); This removes the need for CallExpression::execute() to care about which kind of function it's calling. :^)
2020-03-13 10:08:52 +01:00
#include <LibJS/ScriptFunction.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. :^)
2020-03-07 19:42:11 +01:00
#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
{
LibJS: Split Function into subclasses NativeFunction and ScriptFunction Both types of functions are now Function and implement calling via: virtual Value call(Interpreter&, Vector<Value> arguments); This removes the need for CallExpression::execute() to care about which kind of function it's calling. :^)
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auto* function = interpreter.heap().allocate<ScriptFunction>(body(), parameters());
LibJS: Allow implicit Value construction from GC-allocated things
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interpreter.set_variable(m_name, function);
return function;
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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}
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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Value ExpressionStatement::execute(Interpreter& interpreter) const
{
return m_expression->execute(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. :^)
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Value CallExpression::execute(Interpreter& interpreter) const
{
LibJS: Add operator precedence parsing Obey precedence and associativity rules when parsing expressions with chained operators.
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auto callee = m_callee->execute(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
ASSERT(callee.is_object());
LibJS: Split Function into subclasses NativeFunction and ScriptFunction Both types of functions are now Function and implement calling via: virtual Value call(Interpreter&, Vector<Value> arguments); This removes the need for CallExpression::execute() to care about which kind of function it's calling. :^)
2020-03-13 10:08:52 +01:00
ASSERT(callee.as_object()->is_function());
auto* function = static_cast<Function*>(callee.as_object());
LibJS: Add NativeFunction, a callable wrapper around a C++ lambda This can be used to implement arbitrary functionality, callable from JavaScript. To make this work, I had to change the way CallExpression passes arguments to the callee. Instead of a HashMap<String, Value>, we now pass an ordered list of Argument { String name; Value value; }. This patch includes a native "print(argument)" function. :^)
2020-03-12 19:53:31 +01:00
LibJS: Split Function into subclasses NativeFunction and ScriptFunction Both types of functions are now Function and implement calling via: virtual Value call(Interpreter&, Vector<Value> arguments); This removes the need for CallExpression::execute() to care about which kind of function it's calling. :^)
2020-03-13 10:08:52 +01:00
Vector<Value> argument_values;
for (size_t i = 0; i < m_arguments.size(); ++i)
argument_values.append(m_arguments[i].execute(interpreter));
LibJS: Allow functions to take arguments (#1405)
2020-03-12 19:22:13 +08:00
LibJS: Split Function into subclasses NativeFunction and ScriptFunction Both types of functions are now Function and implement calling via: virtual Value call(Interpreter&, Vector<Value> arguments); This removes the need for CallExpression::execute() to care about which kind of function it's calling. :^)
2020-03-13 10:08:52 +01:00
return function->call(interpreter, move(argument_values));
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
}
Value ReturnStatement::execute(Interpreter& interpreter) const
{
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.:
2020-03-11 19:27:43 +01:00
auto value = argument() ? argument()->execute(interpreter) : js_undefined();
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
interpreter.do_return();
return value;
}
LibJS: Implement if statements If statements execute a certain action or an alternative one depending on whether the tested condition is true or false, this commit helps establish basic control flow capabilities in the AST.
2020-03-08 07:58:58 +02:00
Value IfStatement::execute(Interpreter& interpreter) const
{
auto predicate_result = m_predicate->execute(interpreter);
LibJS: Implement basic boolean coercion We can't expect the conditionals in "if" and "while" statements to always return a bool, so we need to know how to boolify a JS::Value.
2020-03-10 08:46:20 +01:00
if (predicate_result.to_boolean())
LibJS: Implement if statements If statements execute a certain action or an alternative one depending on whether the tested condition is true or false, this commit helps establish basic control flow capabilities in the AST.
2020-03-08 07:58:58 +02:00
return interpreter.run(*m_consequent);
else
return interpreter.run(*m_alternate);
}
LibJS: Implement While statements
2020-03-09 03:22:21 +08:00
Value WhileStatement::execute(Interpreter& interpreter) const
{
Value last_value = js_undefined();
LibJS: Implement basic boolean coercion We can't expect the conditionals in "if" and "while" statements to always return a bool, so we need to know how to boolify a JS::Value.
2020-03-10 08:46:20 +01:00
while (m_predicate->execute(interpreter).to_boolean()) {
LibJS: Implement While statements
2020-03-09 03:22:21 +08:00
last_value = interpreter.run(*m_body);
}
return last_value;
}
LibJS: Implement for statement
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Value ForStatement::execute(Interpreter& interpreter) const
{
LibJS: Evaluate for statements in their own scope if necessary We now evaluate for loops in their own scope if their init statement is a lexical declaration. Evaluating for loops in their own scope allow us to obtain expected behaviour, which means for example, that the block-scoped variables declared in a for statement will be limited to the scope of the for loop's body and statement and not to that of the current scope (i.e the one where the for statement was made)
2020-03-14 13:56:49 +02:00
OwnPtr<BlockStatement> wrapper;
if (m_init->is_variable_declaration() && static_cast<const VariableDeclaration*>(m_init.ptr())->declaration_type() != DeclarationType::Var) {
wrapper = make<BlockStatement>();
interpreter.enter_scope(*wrapper, {}, ScopeType::Block);
}
LibJS: Implement for statement
2020-03-12 23:12:12 +11:00
Value last_value = js_undefined();
if (m_init)
m_init->execute(interpreter);
if (m_test) {
while (m_test->execute(interpreter).to_boolean()) {
last_value = interpreter.run(*m_body);
if (m_update)
m_update->execute(interpreter);
}
} else {
while (true) {
last_value = interpreter.run(*m_body);
if (m_update)
m_update->execute(interpreter);
}
}
LibJS: Evaluate for statements in their own scope if necessary We now evaluate for loops in their own scope if their init statement is a lexical declaration. Evaluating for loops in their own scope allow us to obtain expected behaviour, which means for example, that the block-scoped variables declared in a for statement will be limited to the scope of the for loop's body and statement and not to that of the current scope (i.e the one where the for statement was made)
2020-03-14 13:56:49 +02:00
if (wrapper)
interpreter.exit_scope(*wrapper);
LibJS: Implement for statement
2020-03-12 23:12:12 +11:00
return last_value;
}
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
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);
LibJS: Implement multiplication and division operators
2020-03-12 23:04:52 +11:00
case BinaryOp::Asterisk:
return mul(lhs_result, rhs_result);
case BinaryOp::Slash:
return div(lhs_result, rhs_result);
LibJS: Add typed comparison operator The `===` operator allows us to compare two values while taking their type into consideration.
2020-03-08 07:53:02 +02:00
case BinaryOp::TypedEquals:
return typed_eq(lhs_result, rhs_result);
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
case BinaryOp::TypedInequals:
LibJS: Use Value::to_boolean() wherever we haven't checked is_boolean() Unless we've verified that a Value is a boolean, we should not be calling as_bool() on it.
2020-03-10 11:08:37 +01:00
return Value(!typed_eq(lhs_result, rhs_result).to_boolean());
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::GreaterThan:
return greater_than(lhs_result, rhs_result);
LibJS: Implement <= and >= binary operators
2020-03-12 23:07:08 +11:00
case BinaryOp::GreaterThanEquals:
return greater_than_equals(lhs_result, rhs_result);
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::LessThan:
return less_than(lhs_result, rhs_result);
LibJS: Implement <= and >= binary operators
2020-03-12 23:07:08 +11:00
case BinaryOp::LessThanEquals:
return less_than_equals(lhs_result, rhs_result);
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::BitwiseAnd:
return bitwise_and(lhs_result, rhs_result);
case BinaryOp::BitwiseOr:
return bitwise_or(lhs_result, rhs_result);
case BinaryOp::BitwiseXor:
return bitwise_xor(lhs_result, rhs_result);
case BinaryOp::LeftShift:
return left_shift(lhs_result, rhs_result);
case BinaryOp::RightShift:
return right_shift(lhs_result, rhs_result);
LibJS: Add typed comparison operator The `===` operator allows us to compare two values while taking their type into consideration.
2020-03-08 07:53:02 +02:00
}
ASSERT_NOT_REACHED();
}
LibJS: Implement logical expressions Logical expressions are expressions which can return either true or false according to a provided condition.
2020-03-08 07:55:44 +02:00
Value LogicalExpression::execute(Interpreter& interpreter) const
{
LibJS: Implement basic boolean coercion We can't expect the conditionals in "if" and "while" statements to always return a bool, so we need to know how to boolify a JS::Value.
2020-03-10 08:46:20 +01:00
auto lhs_result = m_lhs->execute(interpreter).to_boolean();
auto rhs_result = m_rhs->execute(interpreter).to_boolean();
LibJS: Implement logical expressions Logical expressions are expressions which can return either true or false according to a provided condition.
2020-03-08 07:55:44 +02:00
switch (m_op) {
case LogicalOp::And:
return Value(lhs_result && rhs_result);
case LogicalOp::Or:
return Value(lhs_result || rhs_result);
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
}
ASSERT_NOT_REACHED();
}
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
Value UnaryExpression::execute(Interpreter& interpreter) const
{
auto lhs_result = m_lhs->execute(interpreter);
switch (m_op) {
LibJS: Rename BitNot -> BitwiseNot to match other bitwise operators
2020-03-14 20:43:35 +02:00
case UnaryOp::BitwiseNot:
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
return bitwise_not(lhs_result);
LibJS: Move logical not operator to new unary expression class
2020-03-09 19:04:44 +02:00
case UnaryOp::Not:
LibJS: Use Value::to_boolean() wherever we haven't checked is_boolean() Unless we've verified that a Value is a boolean, we should not be calling as_bool() on it.
2020-03-10 11:08:37 +01:00
return Value(!lhs_result.to_boolean());
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
}
ASSERT_NOT_REACHED();
}
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
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
{
LibJS: Include the operator in BinaryExpression dumps
2020-03-07 23:16:34 +01:00
const char* op_string = nullptr;
switch (m_op) {
case BinaryOp::Plus:
op_string = "+";
break;
case BinaryOp::Minus:
op_string = "-";
break;
LibJS: Implement multiplication and division operators
2020-03-12 23:04:52 +11:00
case BinaryOp::Asterisk:
op_string = "*";
break;
case BinaryOp::Slash:
op_string = "/";
break;
LibJS: Add typed comparison operator The `===` operator allows us to compare two values while taking their type into consideration.
2020-03-08 07:53:02 +02:00
case BinaryOp::TypedEquals:
op_string = "===";
break;
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
case BinaryOp::TypedInequals:
op_string = "!==";
break;
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::GreaterThan:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = ">";
break;
LibJS: Implement <= and >= binary operators
2020-03-12 23:07:08 +11:00
case BinaryOp::GreaterThanEquals:
op_string = ">=";
break;
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::LessThan:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = "<";
break;
LibJS: Implement <= and >= binary operators
2020-03-12 23:07:08 +11:00
case BinaryOp::LessThanEquals:
op_string = "<=";
break;
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::BitwiseAnd:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = "&";
break;
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::BitwiseOr:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = "|";
break;
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::BitwiseXor:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = "^";
break;
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::LeftShift:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = "<<";
break;
LibJS: Move Value ops into Value.cpp and tweak BinaryOp names
2020-03-10 11:35:05 +01:00
case BinaryOp::RightShift:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = ">>";
break;
LibJS: Add typed comparison operator The `===` operator allows us to compare two values while taking their type into consideration.
2020-03-08 07:53:02 +02:00
}
print_indent(indent);
printf("%s\n", class_name());
m_lhs->dump(indent + 1);
print_indent(indent + 1);
printf("%s\n", op_string);
m_rhs->dump(indent + 1);
}
LibJS: Implement logical expressions Logical expressions are expressions which can return either true or false according to a provided condition.
2020-03-08 07:55:44 +02:00
void LogicalExpression::dump(int indent) const
{
const char* op_string = nullptr;
switch (m_op) {
case LogicalOp::And:
op_string = "&&";
break;
case LogicalOp::Or:
op_string = "||";
break;
LibJS: Include the operator in BinaryExpression dumps
2020-03-07 23:16:34 +01:00
}
print_indent(indent);
printf("%s\n", class_name());
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
m_lhs->dump(indent + 1);
LibJS: Include the operator in BinaryExpression dumps
2020-03-07 23:16:34 +01:00
print_indent(indent + 1);
printf("%s\n", op_string);
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
m_rhs->dump(indent + 1);
}
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
void UnaryExpression::dump(int indent) const
{
const char* op_string = nullptr;
switch (m_op) {
LibJS: Rename BitNot -> BitwiseNot to match other bitwise operators
2020-03-14 20:43:35 +02:00
case UnaryOp::BitwiseNot:
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
op_string = "~";
break;
LibJS: Move logical not operator to new unary expression class
2020-03-09 19:04:44 +02:00
case UnaryOp::Not:
op_string = "!";
break;
LibJS: Add new bitwise and relational operators Do note that when it comes to evaluating binary expressions, we are asserting in multiple contexts that the values we're operating on are numbers, we should probably handle other value types to be more tolerant in the future, since for example, adding a number and a string, in which case the number is converted to a string implicitly which is then concatenated, although ugly, is valid javascript.
2020-03-08 23:27:18 +02:00
}
print_indent(indent);
printf("%s\n", class_name());
print_indent(indent + 1);
printf("%s\n", op_string);
m_lhs->dump(indent + 1);
}
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
void CallExpression::dump(int indent) const
{
LibJS: Add operator precedence parsing Obey precedence and associativity rules when parsing expressions with chained operators.
2020-03-12 23:02:41 +01:00
ASTNode::dump(indent);
m_callee->dump(indent + 1);
LibJS: Dump CallExpression arguments (if any)
2020-03-12 19:34:59 +01:00
for (auto& argument : m_arguments)
argument.dump(indent + 1);
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: Defer Value construction until a Literal is executed Remove the need to construct a full Value during parsing. This means we don't have to worry about plumbing the heap into the parser. The Literal ASTNode now has a bunch of subclasses that synthesize a Value on demand.
2020-03-12 12:19:11 +01:00
void StringLiteral::dump(int indent) const
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
{
print_indent(indent);
LibJS: Defer Value construction until a Literal is executed Remove the need to construct a full Value during parsing. This means we don't have to worry about plumbing the heap into the parser. The Literal ASTNode now has a bunch of subclasses that synthesize a Value on demand.
2020-03-12 12:19:11 +01:00
printf("StringLiteral \"%s\"\n", m_value.characters());
}
void NumericLiteral::dump(int indent) const
{
print_indent(indent);
LibJS: Fix NumericLiteral::dump() output
2020-03-12 19:36:24 +01:00
printf("NumericLiteral %g\n", m_value);
LibJS: Defer Value construction until a Literal is executed Remove the need to construct a full Value during parsing. This means we don't have to worry about plumbing the heap into the parser. The Literal ASTNode now has a bunch of subclasses that synthesize a Value on demand.
2020-03-12 12:19:11 +01:00
}
void BooleanLiteral::dump(int indent) const
{
print_indent(indent);
printf("BooleanLiteral %s\n", m_value ? "true" : "false");
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
}
void FunctionDeclaration::dump(int indent) const
{
LibJS: Allow functions to take arguments (#1405)
2020-03-12 19:22:13 +08:00
bool first_time = true;
StringBuilder parameters_builder;
for (const auto& parameter : m_parameters) {
if (first_time)
first_time = false;
else
parameters_builder.append(',');
parameters_builder.append(parameter);
}
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
print_indent(indent);
LibJS: Allow functions to take arguments (#1405)
2020-03-12 19:22:13 +08:00
printf("%s '%s(%s)'\n", class_name(), name().characters(), parameters_builder.build().characters());
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
body().dump(indent + 1);
}
void ReturnStatement::dump(int indent) const
{
ASTNode::dump(indent);
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.:
2020-03-11 19:27:43 +01:00
if (argument())
argument()->dump(indent + 1);
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: Implement if statements If statements execute a certain action or an alternative one depending on whether the tested condition is true or false, this commit helps establish basic control flow capabilities in the AST.
2020-03-08 07:58:58 +02:00
void IfStatement::dump(int indent) const
{
ASTNode::dump(indent);
print_indent(indent);
printf("If\n");
predicate().dump(indent + 1);
consequent().dump(indent + 1);
print_indent(indent);
printf("Else\n");
alternate().dump(indent + 1);
}
LibJS: Implement While statements
2020-03-09 03:22:21 +08:00
void WhileStatement::dump(int indent) const
{
ASTNode::dump(indent);
print_indent(indent);
printf("While\n");
predicate().dump(indent + 1);
body().dump(indent + 1);
}
LibJS: Implement for statement
2020-03-12 23:12:12 +11:00
void ForStatement::dump(int indent) const
{
ASTNode::dump(indent);
print_indent(indent);
printf("For\n");
if (init())
init()->dump(indent + 1);
if (test())
test()->dump(indent + 1);
if (update())
update()->dump(indent + 1);
body().dump(indent + 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.
2020-03-09 21:13:55 +01:00
Value Identifier::execute(Interpreter& interpreter) const
{
return interpreter.get_variable(string());
}
void Identifier::dump(int indent) const
{
print_indent(indent);
printf("Identifier \"%s\"\n", m_string.characters());
}
Value AssignmentExpression::execute(Interpreter& interpreter) const
{
ASSERT(m_lhs->is_identifier());
auto name = static_cast<const Identifier&>(*m_lhs).string();
auto rhs_result = m_rhs->execute(interpreter);
switch (m_op) {
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::Assignment:
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
interpreter.set_variable(name, rhs_result);
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::AdditionAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
rhs_result = add(m_lhs->execute(interpreter), rhs_result);
interpreter.set_variable(name, rhs_result);
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::SubtractionAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
rhs_result = sub(m_lhs->execute(interpreter), rhs_result);
interpreter.set_variable(name, rhs_result);
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::MultiplicationAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
rhs_result = mul(m_lhs->execute(interpreter), rhs_result);
interpreter.set_variable(name, rhs_result);
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::DivisionAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
rhs_result = div(m_lhs->execute(interpreter), rhs_result);
interpreter.set_variable(name, rhs_result);
break;
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
}
return rhs_result;
}
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
Value UpdateExpression::execute(Interpreter& interpreter) const
{
ASSERT(m_argument->is_identifier());
auto name = static_cast<const Identifier&>(*m_argument).string();
auto previous_value = interpreter.get_variable(name);
ASSERT(previous_value.is_number());
LibJS/AST: Implement prefixed update expressions
2020-03-14 20:44:57 +02:00
int op_result = 0;
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
switch (m_op) {
case UpdateOp::Increment:
LibJS/AST: Implement prefixed update expressions
2020-03-14 20:44:57 +02:00
op_result = 1;
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
break;
case UpdateOp::Decrement:
LibJS/AST: Implement prefixed update expressions
2020-03-14 20:44:57 +02:00
op_result = -1;
LibJS: Implement const variable declarations This also tightens the means of redeclaration of a variable by proxy, since we now have a way of knowing how a variable was initially declared, we can check if it was declared using `let` or `const` and not tolerate redeclaration like we did previously.
2020-03-12 14:24:34 +02:00
break;
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
}
LibJS/AST: Implement prefixed update expressions
2020-03-14 20:44:57 +02:00
interpreter.set_variable(name, Value(previous_value.as_double() + op_result));
if (m_prefixed)
return JS::Value(previous_value.as_double() + op_result);
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
return previous_value;
}
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
void AssignmentExpression::dump(int indent) const
{
const char* op_string = nullptr;
switch (m_op) {
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::Assignment:
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
op_string = "=";
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::AdditionAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
op_string = "+=";
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::SubtractionAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
op_string = "-=";
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::MultiplicationAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
op_string = "*=";
break;
LibJS: Tweak AssignmentOp names
2020-03-12 13:54:56 +01:00
case AssignmentOp::DivisionAssignment:
LibJS: Implement +=, -=, *=, and /= assignment operators
2020-03-12 23:09:15 +11:00
op_string = "/=";
break;
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
}
ASTNode::dump(indent);
print_indent(indent + 1);
printf("%s\n", op_string);
m_lhs->dump(indent + 1);
m_rhs->dump(indent + 1);
}
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
void UpdateExpression::dump(int indent) const
{
const char* op_string = nullptr;
switch (m_op) {
case UpdateOp::Increment:
op_string = "++";
break;
case UpdateOp::Decrement:
op_string = "--";
break;
}
ASTNode::dump(indent);
print_indent(indent + 1);
LibJS/AST: Implement prefixed update expressions
2020-03-14 20:44:57 +02:00
if (m_prefixed)
printf("%s\n", op_string);
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
m_argument->dump(indent + 1);
LibJS/AST: Implement prefixed update expressions
2020-03-14 20:44:57 +02:00
if (!m_prefixed) {
print_indent(indent + 1);
printf("%s\n", op_string);
}
LibJS: Implement update expressions Note that currently only the non-prefixed variant is supported (i.e i++ not ++i), this variant returns the value of the argument before the update.
2020-03-12 13:45:45 +02:00
}
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
Value VariableDeclaration::execute(Interpreter& interpreter) const
{
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`.
2020-03-11 21:09:20 +02:00
interpreter.declare_variable(name().string(), m_declaration_type);
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
if (m_initializer) {
auto initalizer_result = m_initializer->execute(interpreter);
interpreter.set_variable(name().string(), initalizer_result);
}
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`.
2020-03-11 21:09:20 +02:00
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
return js_undefined();
}
void VariableDeclaration::dump(int indent) const
{
LibJS: Implement const variable declarations This also tightens the means of redeclaration of a variable by proxy, since we now have a way of knowing how a variable was initially declared, we can check if it was declared using `let` or `const` and not tolerate redeclaration like we did previously.
2020-03-12 14:24:34 +02:00
const char* declaration_type_string = nullptr;
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`.
2020-03-11 21:09:20 +02:00
switch (m_declaration_type) {
case DeclarationType::Let:
LibJS: Implement const variable declarations This also tightens the means of redeclaration of a variable by proxy, since we now have a way of knowing how a variable was initially declared, we can check if it was declared using `let` or `const` and not tolerate redeclaration like we did previously.
2020-03-12 14:24:34 +02:00
declaration_type_string = "Let";
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`.
2020-03-11 21:09:20 +02:00
break;
case DeclarationType::Var:
LibJS: Implement const variable declarations This also tightens the means of redeclaration of a variable by proxy, since we now have a way of knowing how a variable was initially declared, we can check if it was declared using `let` or `const` and not tolerate redeclaration like we did previously.
2020-03-12 14:24:34 +02:00
declaration_type_string = "Var";
break;
case DeclarationType::Const:
declaration_type_string = "Const";
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`.
2020-03-11 21:09:20 +02:00
break;
}
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
ASTNode::dump(indent);
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`.
2020-03-11 21:09:20 +02:00
print_indent(indent + 1);
LibJS: Implement const variable declarations This also tightens the means of redeclaration of a variable by proxy, since we now have a way of knowing how a variable was initially declared, we can check if it was declared using `let` or `const` and not tolerate redeclaration like we did previously.
2020-03-12 14:24:34 +02:00
printf("%s\n", declaration_type_string);
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
m_name->dump(indent + 1);
if (m_initializer)
m_initializer->dump(indent + 1);
}
LibJS: Add a very simple ObjectExpression for "var x = {}" This allows us to allocate an empty new Object on the GC heap.
2020-03-09 21:28:31 +01:00
void ObjectExpression::dump(int indent) const
{
ASTNode::dump(indent);
}
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.:
2020-03-11 19:27:43 +01:00
void ExpressionStatement::dump(int indent) const
{
ASTNode::dump(indent);
m_expression->dump(indent + 1);
}
LibJS: Add a very simple ObjectExpression for "var x = {}" This allows us to allocate an empty new Object on the GC heap.
2020-03-09 21:28:31 +01:00
Value ObjectExpression::execute(Interpreter& interpreter) const
{
LibJS: Allow implicit Value construction from GC-allocated things
2020-03-12 19:57:40 +01:00
return interpreter.heap().allocate<Object>();
LibJS: Add a very simple ObjectExpression for "var x = {}" This allows us to allocate an empty new Object on the GC heap.
2020-03-09 21:28:31 +01:00
}
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
void MemberExpression::dump(int indent) const
{
ASTNode::dump(indent);
m_object->dump(indent + 1);
m_property->dump(indent + 1);
}
Value MemberExpression::execute(Interpreter& interpreter) const
{
auto object_result = m_object->execute(interpreter).to_object(interpreter.heap());
ASSERT(object_result.is_object());
String property_name;
if (m_property->is_identifier()) {
property_name = static_cast<const Identifier&>(*m_property).string();
} else {
ASSERT_NOT_REACHED();
}
return object_result.as_object()->get(property_name);
}
LibJS: Defer Value construction until a Literal is executed Remove the need to construct a full Value during parsing. This means we don't have to worry about plumbing the heap into the parser. The Literal ASTNode now has a bunch of subclasses that synthesize a Value on demand.
2020-03-12 12:19:11 +01:00
Value StringLiteral::execute(Interpreter& interpreter) const
{
LibJS: Allow implicit Value construction from GC-allocated things
2020-03-12 19:57:40 +01:00
return js_string(interpreter.heap(), m_value);
LibJS: Defer Value construction until a Literal is executed Remove the need to construct a full Value during parsing. This means we don't have to worry about plumbing the heap into the parser. The Literal ASTNode now has a bunch of subclasses that synthesize a Value on demand.
2020-03-12 12:19:11 +01:00
}
Value NumericLiteral::execute(Interpreter&) const
{
return Value(m_value);
}
Value BooleanLiteral::execute(Interpreter&) const
{
return Value(m_value);
}
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
}
Reference in a new issue Copy permalink