static stmt_node *statement(void){
stmt_node *stmtn = newStmtNode();
if(match(TOKEN_IDENTIFIER, NO_CONSUME) ||
match(TOKEN_SCOL, NO_CONSUME)){
if((stmtn->assn = assignment()) != NULL)
return stmtn;
}
else if(match(TOKEN_TYPEKEY, NO_CONSUME)){
if((stmtn->decn = declaration()) != NULL)
return stmtn;
}
else if(match(TOKEN_IFKEY, NO_CONSUME)){
if((stmtn->ifn = if_()) != NULL)
return stmtn;
}
else if(match(TOKEN_WHILEKEY,NO_CONSUME)){
if((stmtn->whilen = while_()) != NULL)
return stmtn;
}
else if(match(TOKEN_FORKEY, NO_CONSUME)){
if((stmtn->forn = for_()) != NULL)
return stmtn;
}
else if((stmtn->lCur = match(TOKEN_LCUR, CONSUME)) != NULL){
if((stmtn->sln = statement_list()) != error)
if((stmtn->rCur = match(TOKEN_RCUR, CONSUME)) != NULL)
return stmtn;
}
else if((stmtn->ins = match(TOKEN_INSTRUCTION, CONSUME)) != NULL)
return stmtn;
freeStmt(stmtn);
return NULL;
}
lint combination(lint n, lint m) {
lint res = 1;
if (2 * m > n) m = n - m;
for_(i,0,m) res = res * (n - i) / (i + 1);
return res;
}
