public function map(array $args, Scheme_Env $env)
{
$this->requireExactly(2, $args);
$this->requireList($args[1]);
list($func, $list) = $args;
$interp = $env->getInterpreter();
$result = array();
foreach ($list->listToArray() as $value) {
$result[] = $interp->evaluate($env, Scheme_Utils::mkList($func, $value));
}
return Scheme_Utils::arrayToList($result);
}
public function evaluate(Scheme_Env $execEnv, array $args)
{
if (count($args) != count($this->argNames)) {
throw new Scheme_Error("Expected " . count($this->argNames) . " but got " . count($args));
}
$argCount = count($this->argNames);
$interp = $execEnv->getInterpreter();
$bodyEnv = $this->defnEnv->createChildEnv();
for ($i = 0; $i < $argCount; ++$i) {
$value = $interp->evaluate($execEnv, $args[$i]);
$bodyEnv->bind($this->argNames[$i], $value);
}
return new Scheme_TailCall($this->body, $bodyEnv);
}
public function letrec(array $args, Scheme_Env $env)
{
$this->requireExactly(2, $args);
$bindings = $args[0];
$body = $args[1];
$interpreter = $env->getInterpreter();
$newEnv = $env->createChildEnv();
$this->requireList($bindings);
$initedBindings = array();
foreach ($bindings->listToArray() as $binding) {
$this->requireList($binding);
$bindingArray = $binding->listToArray();
$this->requireExactly(2, $bindingArray);
$var = $bindingArray[0];
$expr = $bindingArray[1];
$this->requireSymbol($var);
$value = $interpreter->evaluate($newEnv, $expr);
$initedBindings[$var->value] = $value;
}
$newEnv->bindAll($initedBindings);
return new Scheme_TailCall($body, $newEnv);
}
