private function expandSubLists(Environment $env, ListForm $form)
{
if (!count($form->toArray())) {
return $form;
}
return new ListForm(array_merge([$form->nth(0)], $this->expandList($env, $form->cdr())));
}
public function evaluate(Environment $env, ListForm $args)
{
$name = $args->nth(0)->getSymbol();
$macroArgs = $args->nth(1);
$macroBody = $args->nth(2);
$env[$name] = new MacroOp($macroArgs, $macroBody);
}
public function evaluate(Environment $env, ListForm $args)
{
$predicate = $args->nth(0);
$trueForm = $args->nth(1);
$elseForm = $args->nth(2);
$form = $predicate->evaluate($env) ? $trueForm : $elseForm;
return $form ? $form->evaluate($env) : null;
}
public function evaluate(Environment $env, ListForm $args)
{
$pairs = $args->toArray();
foreach ($pairs as $pair) {
list($predicate, $trueForm) = $pair->toArray();
if ($predicate->evaluate($env)) {
return $trueForm->evaluate($env);
}
}
return null;
}
private function wrapSymbols(ListForm $rawBody)
{
$wrappedBody = array_map(function ($form) {
if ($form instanceof ListForm) {
return $this->wrapSymbols($form);
}
if (is_string($form)) {
return new SymbolForm($form);
}
return $form;
}, $rawBody->toArray());
return new ListForm($wrappedBody);
}
public function evaluate(Environment $env, ListForm $args)
{
$symbols = $args->nth(0)->toArray();
$argNames = $this->getMappedSymbols($symbols);
$bodyForms = $args->cdr()->toArray();
return function () use($env, $argNames, $bodyForms) {
$subEnv = clone $env;
$vars = array_combine($argNames, func_get_args());
foreach ($vars as $name => $value) {
$subEnv[$name] = $value;
}
$value = null;
foreach ($bodyForms as $form) {
$value = $form->evaluate($subEnv);
}
return $value;
};
}
public function evaluate(Environment $env, ListForm $args)
{
$name = $args->nth(0)->getSymbol();
$env[$name] = $args->nth(1)->evaluate($env);
}
public function evaluate(Environment $env, ListForm $args)
{
list($value) = $args->getAst();
return $value;
}
private function evaluateArgs(Environment $env, ListForm $args)
{
return array_map(function ($arg) use($env) {
return $arg->evaluate($env);
}, $args->toArray());
}