private function compile(array $tokens)
{
$cg = (object) ['ts' => TokenStream::fromSlice($tokens), 'parsers' => []];
traverse(rtoken('/^(T_\\w+)·(\\w+)$/')->onCommit(function (Ast $result) use($cg) {
$token = $result->token();
$id = $this->lookupCapture($token);
$type = $this->lookupTokenType($token);
$cg->parsers[] = token($type)->as($id);
}), ($parser = chain(rtoken('/^·\\w+$/')->as('type'), token('('), optional(ls(either(future($parser)->as('parser'), chain(token(T_FUNCTION), parentheses()->as('args'), braces()->as('body'))->as('function'), string()->as('string'), rtoken('/^T_\\w+·\\w+$/')->as('token'), rtoken('/^T_\\w+$/')->as('constant'), rtoken('/^·this$/')->as('this'), label()->as('label'))->as('parser'), token(',')))->as('args'), commit(token(')')), optional(rtoken('/^·\\w+$/')->as('label'), null)))->onCommit(function (Ast $result) use($cg) {
$cg->parsers[] = $this->compileParser($result->type, $result->args, $result->label);
}), $this->layer('{', '}', braces(), $cg), $this->layer('[', ']', brackets(), $cg), $this->layer('(', ')', parentheses(), $cg), rtoken('/^···(\\w+)$/')->onCommit(function (Ast $result) use($cg) {
$id = $this->lookupCapture($result->token());
$cg->parsers[] = layer()->as($id);
}), token(T_STRING, '·')->onCommit(function (Ast $result) use($cg) {
$offset = \count($cg->parsers);
if (0 !== $this->dominance || 0 === $offset) {
$this->fail(self::E_BAD_DOMINANCE, $offset, $result->token()->line());
}
$this->dominance = $offset;
}), rtoken('/·/')->onCommit(function (Ast $result) {
$token = $result->token();
$this->fail(self::E_BAD_CAPTURE, $token, $token->line());
}), any()->onCommit(function (Ast $result) use($cg) {
$cg->parsers[] = token($result->token());
}))->parse($cg->ts);
// check if macro dominance '·' is last token
if ($this->dominance === \count($cg->parsers)) {
$this->fail(self::E_BAD_DOMINANCE, $this->dominance, $cg->ts->last()->line());
}
$this->specificity = \count($cg->parsers);
if ($this->specificity > 1) {
if (0 === $this->dominance) {
$pattern = chain(...$cg->parsers);
} else {
/*
dominat macros are partially wrapped in commit()s and dominance
is the offset used as the 'event horizon' point... once the entry
point is matched, there is no way back and a parser error arises
*/
$prefix = array_slice($cg->parsers, 0, $this->dominance);
$suffix = array_slice($cg->parsers, $this->dominance);
$pattern = chain(...array_merge($prefix, array_map(commit::class, $suffix)));
}
} else {
/*
micro optimization to save one function call for every token on the subject
token stream whenever the macro pattern consists of a single parser
*/
$pattern = $cg->parsers[0];
}
return $pattern;
}
private function compilePattern(int $line, array $tokens) : Parser
{
if (!$tokens) {
$this->fail(self::E_EMPTY_PATTERN, $line);
}
$ts = TokenStream::fromSlice($tokens);
traverse(either(consume(chain(token(T_NS_SEPARATOR), token(T_NS_SEPARATOR), parentheses()->as('cloaked')))->onCommit(function (Ast $result) use($ts) {
$ts->inject(TokenStream::fromSequence(...$result->cloaked));
$ts->skip(...TokenStream::SKIPPABLE);
}), rtoken('/^(T_\\w+)·(\\w+)$/')->onCommit(function (Ast $result) {
$token = $result->token();
$id = $this->lookupCapture($token);
$type = $this->lookupTokenType($token);
$this->parsers[] = token($type)->as($id);
}), ($parser = chain(rtoken('/^·\\w+$/')->as('parser_type'), token('('), optional(ls(either(future($parser)->as('parser'), string()->as('string'), rtoken('/^T_\\w+·\\w+$/')->as('token'), rtoken('/^T_\\w+$/')->as('constant'), word()->as('word')), token(',')))->as('args'), commit(token(')')), optional(rtoken('/^·\\w+$/')->as('label'))))->onCommit(function (Ast $result) {
$this->parsers[] = $this->compileParser($result->array());
}), $this->layer('{', '}', braces()), $this->layer('[', ']', brackets()), $this->layer('(', ')', parentheses()), rtoken('/^···(\\w+)$/')->onCommit(function (Ast $result) {
$id = $this->lookupCapture($result->token());
$this->parsers[] = layer()->as($id);
}), token(T_STRING, '·')->onCommit(function (Ast $result) use($ts) {
$offset = \count($this->parsers);
if (0 !== $this->dominance || 0 === $offset) {
$this->fail(self::E_BAD_DOMINANCE, $offset, $result->token()->line());
}
$this->dominance = $offset;
}), rtoken('/·/')->onCommit(function (Ast $result) {
$token = $result->token();
$this->fail(self::E_BAD_CAPTURE, $token, $token->line());
}), any()->onCommit(function (Ast $result) {
$this->parsers[] = token($result->token());
})))->parse($ts);
// check if macro dominance '·' is last token
if ($this->dominance === \count($this->parsers)) {
$this->fail(self::E_BAD_DOMINANCE, $this->dominance, $ts->last()->line());
}
$this->specificity = \count($this->parsers);
if ($this->specificity > 1) {
if (0 === $this->dominance) {
$pattern = chain(...$this->parsers);
} else {
/*
dominat macros are partially wrapped in commit()s and dominance
is the offset used as the 'event horizon' point... once the entry
point is matched, there is no way back and a parser error arises
*/
$prefix = array_slice($this->parsers, 0, $this->dominance);
$suffix = array_slice($this->parsers, $this->dominance);
$pattern = chain(...array_merge($prefix, array_map(commit::class, $suffix)));
}
} else {
/*
micro optimization to save one function call for every token on the subject
token stream whenever the macro pattern consists of a single parser
*/
$pattern = $this->parsers[0];
}
return $pattern;
}
