/**
* Parse a single token
* @param string token
*/
function parseonetoken($token)
{
$x = $token;
$this->a = 0;
// for referencing in WAITING_FOR_DECL_KEYWORD
if (DEBUG) {
printf("%s:%d: Token=[%s] state=%d\n", $this->filename, $this->tokenlineno, $token, $this->state);
}
switch ($this->state) {
case self::INITIALIZE:
$this->prevrule = 0;
$this->preccounter = 0;
$this->firstrule = $this->lastrule = 0;
$this->gp->nrule = 0;
/* Fall thru to next case */
/* Fall thru to next case */
case self::WAITING_FOR_DECL_OR_RULE:
if ($x[0] == '%') {
$this->state = self::WAITING_FOR_DECL_KEYWORD;
} elseif (preg_match('/[a-z]/', $x[0])) {
$this->lhs = LemonSymbol::Symbol_new($x);
$this->nrhs = 0;
$this->lhsalias = 0;
$this->state = self::WAITING_FOR_ARROW;
} elseif ($x[0] == '{') {
if ($this->prevrule === 0) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "There is no prior rule opon which to attach the code\n fragment which begins on this line.");
$this->errorcnt++;
} elseif ($this->prevrule->code != 0) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Code fragment beginning on this line is not the first \\\n to follow the previous rule.");
$this->errorcnt++;
} else {
$this->prevrule->line = $this->tokenlineno;
$this->prevrule->code = substr($x, 1);
}
} elseif ($x[0] == '[') {
$this->state = self::PRECEDENCE_MARK_1;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Token \"%s\" should be either \"%%\" or a nonterminal name.", $x);
$this->errorcnt++;
}
break;
case self::PRECEDENCE_MARK_1:
if (!preg_match('/[A-Z]/', $x[0])) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "The precedence symbol must be a terminal.");
$this->errorcnt++;
} elseif ($this->prevrule === 0) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "There is no prior rule to assign precedence \"[%s]\".", $x);
$this->errorcnt++;
} elseif ($this->prevrule->precsym != 0) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Precedence mark on this line is not the first to follow the previous rule.");
$this->errorcnt++;
} else {
$this->prevrule->precsym = LemonSymbol::Symbol_new($x);
}
$this->state = self::PRECEDENCE_MARK_2;
break;
case self::PRECEDENCE_MARK_2:
if ($x[0] != ']') {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Missing \"]\" on precedence mark.");
$this->errorcnt++;
}
$this->state = self::WAITING_FOR_DECL_OR_RULE;
break;
case self::WAITING_FOR_ARROW:
if ($x[0] == ':' && $x[1] == ':' && $x[2] == '=') {
$this->state = self::IN_RHS;
} elseif ($x[0] == '(') {
$this->state = self::LHS_ALIAS_1;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Expected to see a \":\" following the LHS symbol \"%s\".", $this->lhs->name);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
}
break;
case self::LHS_ALIAS_1:
if (preg_match('/[A-Za-z]/', $x[0])) {
$this->lhsalias = $x;
$this->state = self::LHS_ALIAS_2;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "\"%s\" is not a valid alias for the LHS \"%s\"\n", $x, $this->lhs->name);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
}
break;
case self::LHS_ALIAS_2:
if ($x[0] == ')') {
$this->state = self::LHS_ALIAS_3;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Missing \")\" following LHS alias name \"%s\".", $this->lhsalias);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
}
break;
case self::LHS_ALIAS_3:
if ($x == '::=') {
$this->state = self::IN_RHS;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Missing \"->\" following: \"%s(%s)\".", $this->lhs->name, $this->lhsalias);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
}
break;
case self::IN_RHS:
if ($x[0] == '.') {
$rp = new LemonRule();
$rp->ruleline = $this->tokenlineno;
for ($i = 0; $i < $this->nrhs; $i++) {
$rp->rhs[$i] = $this->rhs[$i];
$rp->rhsalias[$i] = $this->alias[$i];
}
$rp->lhs = $this->lhs;
$rp->lhsalias = $this->lhsalias;
$rp->nrhs = $this->nrhs;
$rp->code = 0;
$rp->precsym = 0;
$rp->index = $this->gp->nrule++;
$rp->nextlhs = $rp->lhs->rule;
$rp->lhs->rule = $rp;
$rp->next = 0;
if ($this->firstrule === 0) {
$this->firstrule = $this->lastrule = $rp;
} else {
$this->lastrule->next = $rp;
$this->lastrule = $rp;
}
$this->prevrule = $rp;
$this->state = self::WAITING_FOR_DECL_OR_RULE;
} elseif (preg_match('/[a-zA-Z]/', $x[0])) {
if ($this->nrhs >= Lemon::MAXRHS) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Too many symbols on RHS or rule beginning at \"%s\".", $x);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
} else {
if (isset($this->rhs[$this->nrhs - 1])) {
$msp = $this->rhs[$this->nrhs - 1];
if ($msp->type == LemonSymbol::MULTITERMINAL) {
$inf = array_reduce($msp->subsym, array($this, '_printmulti'), '');
Lemon::ErrorMsg($this->filename, $this->tokenlineno, 'WARNING: symbol ' . $x . ' will not' . ' be part of previous multiterminal %s', substr($inf, 0, strlen($inf) - 1));
}
}
$this->rhs[$this->nrhs] = LemonSymbol::Symbol_new($x);
$this->alias[$this->nrhs] = 0;
$this->nrhs++;
}
} elseif (($x[0] == '|' || $x[0] == '/') && $this->nrhs > 0) {
$msp = $this->rhs[$this->nrhs - 1];
if ($msp->type != LemonSymbol::MULTITERMINAL) {
$origsp = $msp;
$msp = new LemonSymbol();
$msp->type = LemonSymbol::MULTITERMINAL;
$msp->nsubsym = 1;
$msp->subsym = array($origsp);
$msp->name = $origsp->name;
$this->rhs[$this->nrhs - 1] = $msp;
}
$msp->nsubsym++;
$msp->subsym[$msp->nsubsym - 1] = LemonSymbol::Symbol_new(substr($x, 1));
if (preg_match('/[a-z]/', $x[1]) || preg_match('/[a-z]/', $msp->subsym[0]->name[0])) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Cannot form a compound containing a non-terminal");
$this->errorcnt++;
}
} elseif ($x[0] == '(' && $this->nrhs > 0) {
$this->state = self::RHS_ALIAS_1;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Illegal character on RHS of rule: \"%s\".", $x);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
}
break;
case self::RHS_ALIAS_1:
if (preg_match('/[A-Za-z]/', $x[0])) {
$this->alias[$this->nrhs - 1] = $x;
$this->state = self::RHS_ALIAS_2;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "\"%s\" is not a valid alias for the RHS symbol \"%s\"\n", $x, $this->rhs[$this->nrhs - 1]->name);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
}
break;
case self::RHS_ALIAS_2:
if ($x[0] == ')') {
$this->state = self::IN_RHS;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Missing \")\" following LHS alias name \"%s\".", $this->lhsalias);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_RULE_ERROR;
}
break;
case self::WAITING_FOR_DECL_KEYWORD:
if (preg_match('/[A-Za-z]/', $x[0])) {
$this->declkeyword = $x;
$this->declargslot =& $this->a;
$this->decllnslot =& $this->a;
$this->state = self::WAITING_FOR_DECL_ARG;
if ('name' == $x) {
$this->declargslot =& $this->gp->name;
} elseif ('include' == $x) {
$this->declargslot =& $this->gp->include_code;
$this->decllnslot =& $this->gp->includeln;
} elseif ('include_class' == $x) {
$this->declargslot =& $this->gp->include_classcode;
$this->decllnslot =& $this->gp->include_classln;
} elseif ('declare_class' == $x) {
$this->declargslot =& $this->gp->declare_classcode;
$this->decllnslot =& $this->gp->declare_classln;
} elseif ('code' == $x) {
$this->declargslot =& $this->gp->extracode;
$this->decllnslot =& $this->gp->extracodeln;
} elseif ('token_destructor' == $x) {
$this->declargslot =& $this->gp->tokendest;
$this->decllnslot =& $this->gp->tokendestln;
} elseif ('default_destructor' == $x) {
$this->declargslot =& $this->gp->vardest;
$this->decllnslot =& $this->gp->vardestln;
} elseif ('token_prefix' == $x) {
$this->declargslot =& $this->gp->tokenprefix;
} elseif ('syntax_error' == $x) {
$this->declargslot =& $this->gp->error;
$this->decllnslot =& $this->gp->errorln;
} elseif ('parse_accept' == $x) {
$this->declargslot =& $this->gp->accept;
$this->decllnslot =& $this->gp->acceptln;
} elseif ('parse_failure' == $x) {
$this->declargslot =& $this->gp->failure;
$this->decllnslot =& $this->gp->failureln;
} elseif ('stack_overflow' == $x) {
$this->declargslot =& $this->gp->overflow;
$this->decllnslot =& $this->gp->overflowln;
} else {
if ('extra_argument' == $x) {
$this->declargslot =& $this->gp->arg;
} elseif ('token_type' == $x) {
$this->declargslot =& $this->gp->tokentype;
} elseif ('default_type' == $x) {
$this->declargslot =& $this->gp->vartype;
} elseif ('stack_size' == $x) {
$this->declargslot =& $this->gp->stacksize;
} elseif ('start_symbol' == $x) {
$this->declargslot =& $this->gp->start;
} elseif ('left' == $x) {
$this->preccounter++;
$this->declassoc = LemonSymbol::LEFT;
$this->state = self::WAITING_FOR_PRECEDENCE_SYMBOL;
} elseif ('right' == $x) {
$this->preccounter++;
$this->declassoc = LemonSymbol::RIGHT;
$this->state = self::WAITING_FOR_PRECEDENCE_SYMBOL;
} elseif ('nonassoc' == $x) {
$this->preccounter++;
$this->declassoc = LemonSymbol::NONE;
$this->state = self::WAITING_FOR_PRECEDENCE_SYMBOL;
} elseif ('destructor' == $x) {
$this->state = self::WAITING_FOR_DESTRUCTOR_SYMBOL;
} elseif ('type' == $x) {
$this->state = self::WAITING_FOR_DATATYPE_SYMBOL;
} elseif ('fallback' == $x) {
$this->fallback = 0;
$this->state = self::WAITING_FOR_FALLBACK_ID;
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Unknown declaration keyword: \"%%%s\".", $x);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_DECL_ERROR;
}
}
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Illegal declaration keyword: \"%s\".", $x);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_DECL_ERROR;
}
break;
case self::WAITING_FOR_DESTRUCTOR_SYMBOL:
if (!preg_match('/[A-Za-z]/', $x[0])) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Symbol name missing after %destructor keyword");
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_DECL_ERROR;
} else {
$sp = LemonSymbol::Symbol_new($x);
$this->declargslot =& $sp->destructor;
$this->decllnslot =& $sp->destructorln;
$this->state = self::WAITING_FOR_DECL_ARG;
}
break;
case self::WAITING_FOR_DATATYPE_SYMBOL:
if (!preg_match('/[A-Za-z]/', $x[0])) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Symbol name missing after %destructor keyword");
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_DECL_ERROR;
} else {
$sp = LemonSymbol::Symbol_new($x);
$this->declargslot =& $sp->datatype;
$this->state = self::WAITING_FOR_DECL_ARG;
}
break;
case self::WAITING_FOR_PRECEDENCE_SYMBOL:
if ($x[0] == '.') {
$this->state = self::WAITING_FOR_DECL_OR_RULE;
} elseif (preg_match('/[A-Z]/', $x[0])) {
$sp = LemonSymbol::Symbol_new($x);
if ($sp->prec >= 0) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Symbol \"%s\" has already been given a precedence.", $x);
$this->errorcnt++;
} else {
$sp->prec = $this->preccounter;
$sp->assoc = $this->declassoc;
}
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Can't assign a precedence to \"%s\".", $x);
$this->errorcnt++;
}
break;
case self::WAITING_FOR_DECL_ARG:
if (preg_match('/[A-Za-z0-9{"]/', $x[0])) {
if ($this->declargslot != 0) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "The argument \"%s\" to declaration \"%%%s\" is not the first.", $x[0] == '"' ? substr($x, 1) : $x, $this->declkeyword);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_DECL_ERROR;
} else {
$this->declargslot = $x[0] == '"' || $x[0] == '{' ? substr($x, 1) : $x;
$this->a = 1;
if (!$this->decllnslot) {
$this->decllnslot = $this->tokenlineno;
}
$this->state = self::WAITING_FOR_DECL_OR_RULE;
}
} else {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "Illegal argument to %%%s: %s", $this->declkeyword, $x);
$this->errorcnt++;
$this->state = self::RESYNC_AFTER_DECL_ERROR;
}
break;
case self::WAITING_FOR_FALLBACK_ID:
if ($x[0] == '.') {
$this->state = self::WAITING_FOR_DECL_OR_RULE;
} elseif (!preg_match('/[A-Z]/', $x[0])) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "%%fallback argument \"%s\" should be a token", $x);
$this->errorcnt++;
} else {
$sp = LemonSymbol::Symbol_new($x);
if ($this->fallback === 0) {
$this->fallback = $sp;
} elseif (is_object($sp->fallback)) {
Lemon::ErrorMsg($this->filename, $this->tokenlineno, "More than one fallback assigned to token %s", $x);
$this->errorcnt++;
} else {
$sp->fallback = $this->fallback;
$this->gp->has_fallback = 1;
}
}
break;
case self::RESYNC_AFTER_RULE_ERROR:
/* if ($x[0] == '.') $this->state = self::WAITING_FOR_DECL_OR_RULE;
** break; */
/* if ($x[0] == '.') $this->state = self::WAITING_FOR_DECL_OR_RULE;
** break; */
case self::RESYNC_AFTER_DECL_ERROR:
if ($x[0] == '.') {
$this->state = self::WAITING_FOR_DECL_OR_RULE;
}
if ($x[0] == '%') {
$this->state = self::WAITING_FOR_DECL_KEYWORD;
}
break;
}
}
