Nasal-Interpreter/nasal_import.h

122 lines
3.3 KiB
C++

#ifndef __NASAL_IMPORT_H__
#define __NASAL_IMPORT_H__
class nasal_import
{
private:
uint32_t error;
nasal_lexer import_lex;
nasal_parse import_par;
nasal_ast import_ast;
std::vector<std::string> file_table;
void die(const std::string&,const char*);
bool check_import(const nasal_ast&);
bool check_exist(const std::string&);
void linker(nasal_ast&,nasal_ast&&);
nasal_ast file_import(nasal_ast&);
nasal_ast load(nasal_ast&,uint16_t);
public:
uint32_t err(){return error;}
void link(nasal_parse&,const std::string&);
const std::vector<std::string>& get_file() const {return file_table;}
};
void nasal_import::die(const std::string& file,const char* stage)
{
++error;
std::cout<<"[import] in <\""<<file<<"\">: error(s) occurred in "<<stage<<".\n";
}
bool nasal_import::check_import(const nasal_ast& node)
{
/*
only this kind of node can be recognized as 'import':
call
id:import
call_func
string:'filename'
*/
if(node.type()!=ast_call)
return false;
const std::vector<nasal_ast>& ref_vec=node.child();
if(ref_vec.size()!=2)
return false;
if(ref_vec[0].str()!="import")
return false;
if(ref_vec[1].type()!=ast_callf)
return false;
if(ref_vec[1].child().size()!=1 || ref_vec[1].child()[0].type()!=ast_str)
return false;
return true;
}
bool nasal_import::check_exist(const std::string& file)
{
// avoid importing the same file
for(auto& fname:file_table)
if(file==fname)
return true;
file_table.push_back(file);
return false;
}
void nasal_import::linker(nasal_ast& root,nasal_ast&& add_root)
{
// add children of add_root to the back of root
for(auto& i:add_root.child())
root.add(std::move(i));
}
nasal_ast nasal_import::file_import(nasal_ast& node)
{
// get filename and set node to ast_null
std::string filename=node.child()[1].child()[0].str();
node.clear();
// avoid infinite loading loop
if(check_exist(filename))
return {0,ast_root};
// start importing...
import_lex.scan(filename);
if(import_lex.err())
{
die(filename,"lexer");
return {0,ast_root};
}
import_par.compile(import_lex);
if(import_par.err())
{
die(filename,"parser");
return {0,ast_root};
}
nasal_ast tmp=std::move(import_par.ast());
// check if tmp has 'import'
return load(tmp,file_table.size()-1);
}
nasal_ast nasal_import::load(nasal_ast& root,uint16_t fileindex)
{
nasal_ast new_root(0,ast_root);
for(auto& i:root.child())
if(check_import(i))
linker(new_root,file_import(i));
// add root to the back of new_root
nasal_ast file_head(0,ast_file);
file_head.set_num(fileindex);
new_root.add(std::move(file_head));
linker(new_root,std::move(root));
return new_root;
}
void nasal_import::link(nasal_parse& parse,const std::string& self)
{
// initializing
error=0;
file_table={self};
// scan root and import files,then generate a new ast and return to import_ast
// the main file's index is 0
parse.ast()=load(parse.ast(),0);
}
#endif