function expand(Ast $crossover, Cycle $cycle, Directives $directives, BlueContext $blueContext) : TokenStream
{
$expansion = clone $this->expansion;
if ($this->unsafe) {
hygienize($expansion, ['scope' => $cycle->id()]);
}
return $this->mutate($expansion, $crossover, $cycle, $directives, $blueContext);
}
private function mutate(TokenStream $ts, Ast $context) : TokenStream
{
$cg = (object) ['ts' => clone $ts, 'context' => $context];
if ($this->unsafe && !$this->hasTag('·unsafe')) {
hygienize($cg->ts, $this->cycle->id());
}
if ($this->constant) {
return $cg->ts;
}
traverse(either(token(Token::CLOAKED), consume(chain(rtoken('/^·\\w+$/')->as('expander'), parentheses()->as('args')))->onCommit(function (Ast $result) use($cg) {
$expander = $this->lookupExpander($result->expander);
$args = [];
foreach ($result->args as $arg) {
if ($arg instanceof Token) {
$key = (string) $arg;
if (preg_match('/^·\\w+|T_\\w+·\\w+|···\\w+$/', $key)) {
$arg = $cg->context->{$key};
}
}
if (is_array($arg)) {
array_push($args, ...$arg);
} else {
$args[] = $arg;
}
}
$mutation = $expander(TokenStream::fromSlice($args), $this->cycle->id());
$cg->ts->inject($mutation);
}), consume(chain(rtoken('/^·\\w+|···\\w+$/')->as('label'), operator('···'), braces()->as('expansion')))->onCommit(function (Ast $result) use($cg) {
$index = (string) $result->label;
$context = $cg->context->{$index};
if ($context === null) {
$this->fail(self::E_EXPANSION, $index, $result->label->line(), json_encode(array_keys($cg->context->all()[0]), self::PRETTY_PRINT));
}
$expansion = TokenStream::fromSlice($result->expansion);
// normalize single context
if (array_values($context) !== $context) {
$context = [$context];
}
foreach (array_reverse($context) as $i => $subContext) {
$mutation = $this->mutate($expansion, (new Ast(null, $subContext))->withParent($cg->context));
$cg->ts->inject($mutation);
}
}), consume(rtoken('/^(T_\\w+·\\w+|·\\w+|···\\w+)$/'))->onCommit(function (Ast $result) use($cg) {
$expansion = $cg->context->{(string) $result->token()};
if ($expansion instanceof Token) {
$cg->ts->inject(TokenStream::fromSequence($expansion));
} elseif (is_array($expansion) && \count($expansion)) {
$tokens = [];
array_walk_recursive($expansion, function (Token $token) use(&$tokens) {
$tokens[] = $token;
});
$cg->ts->inject(TokenStream::fromSlice($tokens));
}
}), any()))->parse($cg->ts);
$cg->ts->reset();
if ($this->cloaked) {
traverse(either(consume(token(Token::CLOAKED))->onCommit(function (Ast $result) use($cg) {
$cg->ts->inject(TokenStream::fromSourceWithoutOpenTag((string) $result->token()));
}), any()))->parse($cg->ts);
$cg->ts->reset();
}
return $cg->ts;
}
