bool Scanner::tryParseTypeList(TokenStore::iterator& pos) {
for (int parsed = 0;; parsed++) {
if (pos->t == '+' || pos->t == '-') {
nextLookahead(pos);
}
auto cpPos = pos;
if (!tryParseNSType(cpPos)) {
if (parsed > 0) {
pos = cpPos;
return true;
} else {
return false;
}
}
pos = cpPos;
while (pos->t == T_AS || pos->t == T_SUPER) {
nextLookahead(pos);
if (!tryParseNSType(pos)) {
return false;
}
}
if (pos->t != ',') return true;
nextLookahead(pos);
}
}
bool Scanner::tryParseTypeList(TokenStore::iterator& pos) {
for (;;) {
if (!tryParseNSType(pos)) return false;
if (pos->t == T_AS) {
nextLookahead(pos);
if (!tryParseNSType(pos)) return false;
}
if (pos->t != ',') return true;
nextLookahead(pos);
}
}
bool Scanner::tryParseShapeMemberList(TokenStore::iterator& pos) {
assert(pos->t != ')'); // already determined to be nonempty
for (;;) {
if (!nextIfToken(pos, T_CONSTANT_ENCAPSED_STRING) ||
!nextIfToken(pos, T_DOUBLE_ARROW)) {
return false;
}
if (!tryParseNSType(pos)) return false;
if (pos->t == ')') return true;
if (!nextIfToken(pos, ',')) return false;
if (pos->t == ')') return true;
}
return false;
}
bool Scanner::tryParseFuncTypeList(TokenStore::iterator& pos) {
for (int parsed = 0;;parsed++) {
if (pos->t == T_ELLIPSIS) {
nextLookahead(pos);
return true;
}
auto cpPos = pos;
if (!tryParseNSType(cpPos)) {
if (parsed > 0) {
pos = cpPos;
return true;
} else {
return false;
}
}
pos = cpPos;
if (pos->t != ',') return true;
nextLookahead(pos);
}
}
bool Scanner::tryParseNonEmptyLambdaParams(TokenStore::iterator& pos) {
for (;; nextLookahead(pos)) {
if (pos->t != T_VARIABLE) {
if (pos->t == T_ELLIPSIS) {
nextLookahead(pos);
return true;
}
if (!tryParseNSType(pos)) return false;
if (pos->t == '&') {
nextLookahead(pos);
}
if (pos->t != T_VARIABLE) return false;
}
nextLookahead(pos);
if (pos->t == '=') {
nextLookahead(pos);
parseApproxParamDefVal(pos);
}
if (pos->t != ',') return true;
}
}
int Scanner::getNextToken(ScannerToken &t, Location &l) {
int tokid;
bool la = !m_lookahead.empty();
tokid = fetchToken(t, l);
if (LIKELY(!isUnresolved(tokid))) {
// In the common case, we don't have to perform any resolution
// and we can just return the token
if (UNLIKELY(la)) {
// If we pulled a lookahead token, we need to remove it from
// the lookahead store
m_lookahead.popFront();
}
return tokid;
}
if (!la) {
// If this token didn't come from the lookahead store, we
// need to stash it there
TokenStore::iterator it = m_lookahead.appendNew();
LookaheadToken ltd = { t, l, tokid };
*it = ltd;
}
switch (tokid) {
case T_UNRESOLVED_NEWTYPE:
case T_UNRESOLVED_TYPE: {
auto pos = m_lookahead.begin();
auto typePos = pos;
nextLookahead(pos);
if (isValidClassConstantName(pos->t)) {
typePos->t = tokid == T_UNRESOLVED_TYPE ? T_TYPE : T_NEWTYPE;
} else {
typePos->t = T_STRING;
}
break;
}
case T_UNRESOLVED_LT: {
// Look at subsequent tokens to determine if the '<' character
// is the start of a type list
auto pos = m_lookahead.begin();
auto ltPos = pos;
nextLookahead(pos);
++m_lookaheadLtDepth;
bool isTypeList = tryParseTypeList(pos);
--m_lookaheadLtDepth;
if (isTypeList && pos->t == '>') {
ltPos->t = T_TYPELIST_LT;
pos->t = T_TYPELIST_GT;
} else {
ltPos->t = '<';
}
break;
}
case T_UNRESOLVED_OP: {
// Look at subsequent tokens to determine if the '(' character
// is the start of a lambda expression
auto pos = m_lookahead.begin();
auto opPos = pos;
nextLookahead(pos);
if (pos->t != ')' && pos->t != T_LAMBDA_CP) {
if (!tryParseNonEmptyLambdaParams(pos) || pos->t != ')') {
opPos->t = '(';
break;
}
}
auto cpPos = pos;
nextLookahead(pos);
if (pos->t == ':') {
nextLookahead(pos);
if (!tryParseNSType(pos)) {
opPos->t = '(';
break;
}
}
if (pos->t == T_LAMBDA_ARROW) {
opPos->t = T_LAMBDA_OP;
cpPos->t = T_LAMBDA_CP;
} else {
opPos->t = '(';
}
break;
}
default: always_assert(0);
}
tokid = fetchToken(t, l);
// We pulled a lookahead token, we need to remove it from the
// lookahead store
m_lookahead.popFront();
return tokid;
}
bool
Scanner::tryParseNSType(TokenStore::iterator& pos) {
if (pos->t == '@') {
nextLookahead(pos);
}
if (pos->t == '?') {
nextLookahead(pos);
}
if (pos->t == '(' || pos->t == T_UNRESOLVED_OP) {
nextLookahead(pos);
if (pos->t == T_FUNCTION) {
nextLookahead(pos);
if (pos->t != '(') return false;
nextLookahead(pos);
if (pos->t != ')') {
if (!tryParseFuncTypeList(pos)) return false;
if (pos->t != ')') return false;
}
nextLookahead(pos);
if (pos->t == ')') {
nextLookahead(pos);
return true;
}
if (pos->t != ':') return false;
nextLookahead(pos);
if (!tryParseNSType(pos)) return false;
if (pos->t != ')') return false;
nextLookahead(pos);
return true;
}
if (!tryParseTypeList(pos)) return false;
if (pos->t != ')') return false;
nextLookahead(pos);
return true;
}
if (pos->t == T_NAMESPACE) {
nextLookahead(pos);
if (pos->t != T_NS_SEPARATOR) return false;
nextLookahead(pos);
} else if (pos->t == T_NS_SEPARATOR) {
nextLookahead(pos);
}
for (;;) {
switch (pos->t) {
case T_STRING:
case T_SUPER:
case T_XHP_ATTRIBUTE:
case T_XHP_CATEGORY:
case T_XHP_CHILDREN:
case T_XHP_REQUIRED:
case T_ENUM:
case T_ARRAY:
case T_CALLABLE:
case T_UNRESOLVED_TYPE:
case T_UNRESOLVED_NEWTYPE:
nextLookahead(pos);
break;
case T_SHAPE:
return tryParseShapeType(pos);
case T_XHP_LABEL:
nextLookahead(pos);
return true;
default:
return false;
}
if (pos->t == T_UNRESOLVED_LT) {
TokenStore::iterator ltPos = pos;
nextLookahead(pos);
++m_lookaheadLtDepth;
bool isTypeList = tryParseTypeList(pos);
--m_lookaheadLtDepth;
if (!isTypeList || pos->t != '>') {
ltPos->t = '<';
return false;
}
ltPos->t = T_TYPELIST_LT;
pos->t = T_TYPELIST_GT;
nextLookahead(pos);
return true;
}
if (pos->t != T_NS_SEPARATOR && pos->t != T_DOUBLE_COLON) {
return true;
}
nextLookahead(pos);
}
}
