loading
t = expression();
match(SEMI); } return t; }
TreeNode * if_stmt(void) { TreeNode * t = newStmtNode(IfK); if(t!=NULL) {
match(IF);
match(LPAREN);
t->child[0] = expression(); match(RPAREN);
t->child[1] = statement(); if (token==ELSE) { match(ELSE);
if (t!=NULL) t->child[2] = newStmtNode(ElseK);
t->child[2]->child[0] = statement(); } } return t; }
TreeNode * while_stmt(void) { TreeNode * t = newStmtNode(WhileK); match(WHILE);
match(LPAREN);
if (t!=NULL) t->child[0] = expression(); match(RPAREN);
if (t!=NULL) t->child[1] = statement(); return t;
}
TreeNode * return_stmt(void)
{ }
TreeNode * t = newStmtNode(RetK); if(token == RETURN) match(RETURN); if(token == SEMI) match(SEMI); else {
t->child[0] = expression(); match(SEMI); } return t;
TreeNode * expression(void) { TreeNode * t = simple_exp(); return t; }
TreeNode* var(void) { TreeNode* t = newExpNode(IdK); if ((t!=NULL) && (token==ID)) t->attr.name = copyString(tokenString); match(ID); if(token == LZKH) { match(token); t->type = ArrayUnit; }
t->child[0] = expression(); match(RZKH); }
return t;
TreeNode * simple_exp(void) {
TreeNode * t = additive_expression();
if(t!=NULL){
if (token == LT || token == LE|| token == MT || token == ME||token ==EQ||token ==NEQ) { TreeNode * p = newExpNode(OpK); if(p!=NULL) { p->attr.op = token; p->child[0] = t; match(token); p->child[1] = additive_expression();
}
}
t=p;
} return t; }
TreeNode* additive_expression(void) {
TreeNode * t = term();
while(token == PLUS || token == MINUS) {
TreeNode * p = newExpNode(OpK); p->attr.op = token; p->child[0] = t; match(token);
p->child[1] = term(); t = p; }
return t; }
TreeNode * term(void) {
TreeNode * t = factor();
while ((token==TIMES)||(token==OVER)) {
TreeNode * p = newExpNode(OpK); if (p!=NULL) { p->child[0] = t; p->attr.op = token;
match(token); p->child[1] = factor(); t = p; } }
return t;
}
TreeNode * factor(void) {
TreeNode * t = NULL; switch (token) {
case NUM :
t = newExpNode(ConstK);
if ((t!=NULL) && (token==NUM)) t->attr.val = atoi(tokenString); match(NUM); break; case ID : t = var();
if (token == ASSIGN) { TreeNode* p = newStmtNode(AssignK); p->attr.name = t->attr.name;
match(token); p->child[0] = expression(); t = p; }
if (token == LPAREN ) {
TreeNode * p = newStmtNode(CallK); p->attr.name = t->attr.name;