Nasal-Interpreter/version0.19/nasal_parser.h

388 lines
9.1 KiB
C++

#ifndef __NASAL_PARSER_H__
#define __NASAL_PARSER_H__
#include "nasal_token_type.h"
class nasal_parser
{
private:
ast_tree_node root;
std::stack<token> parse;
std::stack<ast_tree_node> node_cache;
token this_token;
bool error;
public:
nasal_parser()
{
error=false;
this_token.type=0;
}
void get_token()
{
if(parse.empty())
{
this_token.type=0;
return;
}
this_token=parse.top();
parse.pop();
return;
}
void number_expr_process()
{
get_token();
if(this_token.type==__semi)
return;
return;
}
void string_expr_process()
{
get_token();
if(this_token.type==__semi)
return;
return;
}
void identifier_call()
{
get_token();
if(this_token.type==__left_curve)
{
return;
}
else if(this_token.type==__left_brace)
{
return;
}
else if(this_token.type==__dot)
{
return;
}
else if(this_token.type==__semi)
return;
return;
}
void definition()
{
get_token();
if(this_token.type!=__id)
{
std::cout<<">>[Error] parse error in line "<<this_token.line<<": incorrect token behind the declarator."<<std::endl;
error=true;
return;
}
get_token();
if(this_token.type!=__equal && this_token.type!=__semi)
{
std::cout<<">>[Error] parse error in line "<<this_token.line<<": expect \'=\' behind the identifier."<<std::endl;
error=true;
return;
}
else if(this_token.type==__semi)
{
std::cout<<">>[Error] [-Warning] in line "<<this_token.line<<": new variable without initialization."<<std::endl;
error=true;
return;
}
/*
*/
get_token();
if(this_token.type!=__number && this_token.type!=__string)
{
std::cout<<">>[Error] parse error in line "<<this_token.line<<": missing element after \'=\'."<<std::endl;
error=true;
return;
}
get_token();
if(this_token.type!=__semi)
{
std::cout<<">>[Error] parse error in line "<<this_token.line<<": expect \';\' at the end of the statement."<<std::endl;
error=true;
return;
}
return;
}
void parse_main_work()
{
while(!parse.empty())
{
get_token();
switch(this_token.type)
{
case __var:definition();break;
case __id:identifier_call();break;
case __number:number_expr_process();break;
case __string:string_expr_process();break;
case __if:break;
case __while:break;
case __for:break;
case __foreach:break;
case __forindex:break;
case __semi:break;
default:
std::cout<<">>[Error] parse error in line "<<this_token.line<<": ";
print_token(this_token.type);
std::cout<<" in an incorrect place."<<std::endl;
error=true;
break;
}
}
return;
}
void print_parser_stack()
{
if(parse.empty())
return;
int line=0;
std::stack<token> temp;
while(!parse.empty())
{
temp.push(parse.top());
if(line!=temp.top().line)
{
if(line+1==temp.top().line)
{
line=temp.top().line;
if(line==1)
std::cout<<"line "<<line<<" ";
else
std::cout<<std::endl<<"line "<<line<<" ";
}
else
{
while(line!=temp.top().line)
{
++line;
std::cout<<std::endl<<"line "<<line<<" ";
}
}
}
std::cout<<"<";
print_token(temp.top().type);
std::cout<<"> ";
parse.pop();
}
while(!temp.empty())
{
parse.push(temp.top());
temp.pop();
}
std::cout<<std::endl;
return;
}
void parse_process(std::list<token>& lexer)
{
while(!parse.empty())
parse.pop();
std::stack<token> temp;
for(std::list<token>::iterator i=lexer.begin();i!=lexer.end();++i)
{
token temp_parse;
temp_parse=*i;
temp.push(temp_parse);//push this into stack
}
if(temp.empty())
{
std::cout<<">>[Parse] [-Warning] Empty lexer list."<<std::endl;
return;
}
while(!temp.empty())
{
parse.push(temp.top());
temp.pop();
}
return;
}
// for building abstract syntax tree
void number_gen()
{
number_expr t;
t.set_line(parse.top().line);
t.set_number(parse.top().content);
if(node_cache.empty())
node_cache.push(t);
else if((node_cache.top().return_type()==__add_operator || node_cache.top().return_type()==__sub_operator || node_cache.top().return_type()==__mul_operator || node_cache.top().return_type()==__div_operator)
&& (node_cache.top().child_num()==1))
node_cache.top().add_child(t);
else
{
std::cout<<">>[Error] parse error in line "<<parse.top().line<<":missing \';\' at this place."<<std::endl;
error=true;
}
return;
}
void add_sub_operator_gen()
{
operator_expr opt;
opt.set_line(parse.top().line);
opt.set_operator_type(parse.top().type);
if(node_cache.empty())
{
number_expr t;
t.set_line(parse.top().line);
std::string temp_str="0";
t.set_number(temp_str);
opt.add_child(t);
node_cache.push(opt);
}
else if(node_cache.top().return_type()==__number
|| ((node_cache.top().return_type()==__add_operator
|| node_cache.top().return_type()==__sub_operator
|| node_cache.top().return_type()==__mul_operator
|| node_cache.top().return_type()==__div_operator)
&& node_cache.top().child_num()==2))
{
opt.add_child(node_cache.top());
node_cache.pop();
node_cache.push(opt);
}
else
{
std::cout<<">>[Error] parse error in line "<<parse.top().line<<":missing number/calculation at this place."<<std::endl;
error=true;
}
return;
}
void mul_div_operator_gen()
{
operator_expr opt;
opt.set_line(parse.top().line);
opt.set_operator_type(parse.top().type);
if(node_cache.empty())
{
std::cout<<">>[Error] parse error in line "<<parse.top().line<<":missing number at this place(you cannot use * or / as the begin of calculation)."<<std::endl;
error=true;
return;
}
if(node_cache.top().return_type()==__number)
{
// add new leaf node number to operator
opt.add_child(node_cache.top());
node_cache.pop();
node_cache.push(opt);
}
else if(node_cache.top().return_type()==__add_operator || node_cache.top().return_type()==__sub_operator)
{
if(node_cache.top().child_num()!=2)
{
std::cout<<">>[Error] parse error in line "<<parse.top().line<<":missing number at this place."<<std::endl;
error=true;
}
else
{
// calcu * and / first so pick a number from +-'s children nodes
opt.add_child(node_cache.top().return_last_child());
parse.pop();
// add the next number to fix the operator node's children list
if(!parse.empty() && parse.top().type==__number)
{
number_expr t;
t.set_line(parse.top().line);
t.set_number(parse.top().content);
opt.add_child(t);
}
else
{
std::cout<<">>[Error] parse error in line "<<parse.top().line<<":missing number at this place."<<std::endl;
error=true;
return;
}
node_cache.top().return_last_child()=opt;
}
}
else if(node_cache.top().return_type()==__mul_operator || node_cache.top().return_type()==__div_operator)
{
if(node_cache.top().child_num()!=2)
{
std::cout<<">>[Error] parse error in line "<<parse.top().line<<":missing number at this place."<<std::endl;
error=true;
}
else
{
opt.add_child(node_cache.top());
node_cache.pop();
node_cache.push(opt);
}
}
return;
}
void gen_main_prog()
{
error=false;
root.clear_tree();
// initializing
while(!node_cache.empty())
node_cache.pop();
while(!parse.empty())
{
int type=parse.top().type;
bool is_correct=false;
switch(type)
{
case __number:number_gen();break;
case __add_operator:add_sub_operator_gen();break;
case __sub_operator:add_sub_operator_gen();break;
case __mul_operator:mul_div_operator_gen();break;
case __div_operator:mul_div_operator_gen();break;
case __semi:
if(!node_cache.empty())
{
root.add_child(node_cache.top());
node_cache.pop();
}
break;
default:
std::cout<<">>[Error] parse error in line "<<parse.top().line<<":";
print_token(parse.top().type);
std::cout<<" at an incorrect place."<<std::endl;
error=true;
break;
}
parse.pop();
}
if(error)
{
std::cout<<">>[Parse] Error(s) occurred."<<std::endl;
std::cout<<">>[Parse] Complete parsing."<<std::endl;
}
else
{
std::cout<<">>[Parse] 0 error."<<std::endl;
std::cout<<">>[Parse] Complete parsing."<<std::endl;
}
return;
}
void print_ast()
{
std::cout<<">>[Abstract-syntax-tree]"<<std::endl;
root.print(0);
return;
}
void run()
{
if(!error)
root.run();
else
std::cout<<">>[Parse] Error(s) occurred,stop."<<std::endl;
return;
}
};
#endif