XP AST

Abstract syntax tree library used for XP Compiler.

Example

uselang\ast\{Language, Tokens};
$tree= Language::named('PHP')->parse(newTokens('echo PHP_VERSION;'))->tree();
// lang.ast.ParseTree(source: (string))@{// scope => lang.ast.Scope {// parent => null// package => null// imports => []// types => []// }// children => [lang.ast.nodes.EchoStatement {// kind => "echo"// expressions => [lang.ast.nodes.Literal {// kind => "literal"// expression => "PHP_VERSION"// line => 1// }]// line => 1// }]// }

Compile-time metaprogramming

Register transformations by creating classes inside the lang.ast.syntax.php package - see xp-framework/rfc#327

namespacelang\ast\syntax\php;
uselang\ast\Code;
uselang\ast\nodes\{Method, Signature};
uselang\ast\syntax\Extension;
usecodegen\Getters;
class CreateGetters implements Extension {
publicfunctionsetup($language, $emitter) {
$emitter->transform('class', function($codegen, $class) {
if ($class->annotation(Getters::class)) {
foreach ($class->properties() as$property) {
$class->declare(newMethod(
['public'],
$property->name,
newSignature([], $property->type),
[newCode('return $this->'.$property->name)]
));
}
}
return$class;
});
}
}

When compiling the following sourcecode, getters for the id and name members will automatically be added.

usecodegen\Getters;
#[Getters]
class Person {
privateint$id;
privatestring$name;
publicfunction__construct(int$id, string$name) {
$this->id= $id;
$this->name= $name;
}
}