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Nasal-Interpreter/version2.0/nasal_lexer.h
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Valk Richard Li 024e02f963 update
2020-04-07 01:49:29 -07:00

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#ifndef __NASAL_LEXER_H__
#define __NASAL_LEXER_H__
/*
__token_reserve_word:
for,foreach,forindex,while : loop
var,func : definition
break,continue : in loop
return : in function
if,else,elsif : conditional expr
and,or : calculation
nil : special type
__token_identifier:
must begin with '_' or 'a'~'z' or 'A'~'Z'
can include '_' or 'a'~'z' or 'A'~'Z' or '0'~'9'
__token_string:
example:
"string"
'string'
if a string does not end with " or ' then lexer will throw an error
__token_number:
example:
2147483647 (integer)
2.71828 (float)
0xdeadbeef (hex) or 0xDEADBEEF (hex)
0o170001 (oct)
1e-1234 (dec) or 10E2 (dec)
__token_operator:
! + - * / ~
= += -= *= /= ~=
== != > >= < <=
('and' 'or' are operators too but they are recognized as operator in generate_detail_token())
() [] {} ; , . : ?
others: __unknown_operator
*/
/* filenames of lib files */
#ifndef LIB_FILE_NUM
#define LIB_FILE_NUM 11
const std::string lib_filename[LIB_FILE_NUM]=
{
"lib/base.nas",
"lib/bits.nas",
"lib/io.nas",
"lib/math.nas",
"lib/readline.nas",
"lib/regex.nas",
"lib/sqlite.nas",
"lib/system.nas",
"lib/thread.nas",
"lib/unix.nas",
"lib/utf8.nas"
};
#endif
/* reserve words */
#ifndef RESERVE_WORD_NUM
#define RESERVE_WORD_NUM 15
std::string reserve_word[RESERVE_WORD_NUM]=
{
"for","foreach","forindex","while",
"var","func","break","continue","return",
"if","else","elsif","and","or","nil"
};
/* check if an identifier is a reserve word */
int is_reserve_word(std::string str)
{
for(int i=0;i<RESERVE_WORD_NUM;++i)
if(reserve_word[i]==str)
return __token_reserve_word;
return __token_identifier;
}
#endif
class resource_file
{
private:
std::vector<char> source_code;
public:
/*
delete_all_source: clear all the source codes in std::list<char> resource
input_file : input source codes by filenames
load_lib_file : input lib source codes
get_source : get the std::vector<char> source_code
print_resource : print source codes
*/
void delete_all_source();
void input_file(std::string);
void load_lib_file();
std::vector<char>& get_source();
void print_resource();
};
/* struct token: mainly used in nasal_lexer and nasal_parse*/
struct token
{
int line;
int type;
std::string str;
token& operator=(const token& tmp)
{
line=tmp.line;
type=tmp.type;
str=tmp.str;
return *this;
}
};
class nasal_lexer
{
private:
std::list<token> token_list;
std::list<token> detail_token_list;
int error;
std::string identifier_gen(std::vector<char>&,int&,int&);
std::string number_gen (std::vector<char>&,int&,int&);
std::string string_gen (std::vector<char>&,int&,int&);
public:
/*
identifier_gen : scan the source codes and generate identifiers
number_gen : scan the source codes and generate numbers
string_gen : scan the source codes and generate strings
print_token_list : print generated token list
scanner : scan the source codes and generate tokens
generate_detail_token: recognize and change token types to detailed types that can be processed by nasal_parse
get_error : get the number of errors that occurred when generating tokens
get_detail_token : output the detailed tokens,must be used after generate_detail_token()
*/
nasal_lexer();
~nasal_lexer();
void delete_all_tokens();
void print_token_list();
void scanner(std::vector<char>&);
void generate_detail_token();
int get_error();
std::list<token>& get_detail_token_list();
};
void resource_file::delete_all_source()
{
std::vector<char> tmp;
source_code.clear();
source_code.swap(tmp);
return;
}
void resource_file::input_file(std::string filename)
{
char c=0;
std::ifstream fin(filename,std::ios::binary);
if(fin.fail())
{
std::cout<<">> [Resource] cannot open file \'"<<filename<<"\' ."<<std::endl;
fin.close();
return;
}
while(!fin.eof())
{
c=fin.get();
if(fin.eof())
break;
source_code.push_back(c<0? '?':c);
}
fin.close();
return;
}
void resource_file::load_lib_file()
{
source_code.clear();
for(int i=0;i<LIB_FILE_NUM;++i)
{
std::ifstream fin(lib_filename[i],std::ios::binary);
if(fin.fail())
std::cout<<">> [Resource] fatal error: lack \'"<<lib_filename[i]<<"\'"<<std::endl;
else
{
char c=0;
while(!fin.eof())
{
c=fin.get();
if(fin.eof())
break;
source_code.push_back(c<0? '?':c);
}
}
fin.close();
}
return;
}
std::vector<char>& resource_file::get_source()
{
return source_code;
}
void resource_file::print_resource()
{
int line=1;
std::cout<<line<<"\t";
for(int i=0;i<source_code.size();++i)
{
if(32<=source_code[i])
std::cout<<source_code[i];
else
std::cout<<" ";
if(source_code[i]=='\n')
{
++line;
std::cout<<std::endl<<line<<"\t";
}
}
std::cout<<std::endl;
return;
}
std::string nasal_lexer::identifier_gen(std::vector<char>& res,int& ptr,int& line)
{
std::string token_str="";
while(res[ptr]=='_' || ('a'<=res[ptr] && res[ptr]<='z') || ('A'<=res[ptr] && res[ptr]<='Z') || ('0'<=res[ptr] && res[ptr]<='9'))
{
token_str+=res[ptr];
++ptr;
if(ptr>=res.size())
break;
}
// check dynamic identifier "..."
if(res[ptr]=='.')
{
++ptr;
if(ptr<res.size() && res[ptr]=='.')
{
++ptr;
if(ptr<res.size() && res[ptr]=='.')
{
token_str+="...";
++ptr;
}
else
ptr-=2;
}
else
--ptr;
}
return token_str;
}
std::string nasal_lexer::number_gen(std::vector<char>& res,int& ptr,int& line)
{
bool scientific_notation=false;
std::string token_str="";
while(('0'<=res[ptr] && res[ptr]<='9') ||
('a'<=res[ptr] && res[ptr]<='f') ||
('A'<=res[ptr] && res[ptr]<='F') ||
res[ptr]=='.' || res[ptr]=='x' || res[ptr]=='o' ||
res[ptr]=='e' || res[ptr]=='E')
{
token_str+=res[ptr];
if(res[ptr]=='e' || res[ptr]=='E')
{
scientific_notation=true;
++ptr;
break;
}
++ptr;
if(ptr>=res.size())
break;
}
if(scientific_notation && ptr<res.size())
{
if(res[ptr]=='-')
{
token_str+='-';
++ptr;
}
while(ptr<res.size() && '0'<=res[ptr] && res[ptr]<='9')
{
token_str+=res[ptr];
++ptr;
}
}
if(!check_numerable_string(token_str))
{
++error;
std::cout<<">> [Lexer] line "<<line<<": "<<token_str<<" is not a numerable string."<<std::endl;
token_str="0";
}
return token_str;
}
std::string nasal_lexer::string_gen(std::vector<char>& res,int& ptr,int& line)
{
std::string token_str="";
char str_begin=res[ptr];
++ptr;
if(ptr>=res.size())
return token_str;
while(ptr<res.size() && res[ptr]!=str_begin)
{
token_str+=res[ptr];
if(res[ptr]=='\n')
++line;
if(res[ptr]=='\\')
{
++ptr;
switch(res[ptr])
{
case '\\':token_str.pop_back();token_str.push_back('\\');break;
case 'r': token_str.pop_back();token_str.push_back('\r');break;
case 't': token_str.pop_back();token_str.push_back('\t');break;
case 'n': token_str.pop_back();token_str.push_back('\n');break;
case '\'':token_str.pop_back();token_str.push_back('\'');break;
case '\"':token_str.pop_back();token_str.push_back('\"');break;
default: token_str.push_back(res[ptr]);break;
}
}
++ptr;
if(ptr>=res.size())
break;
}
// check if this string ends with a " or '
if(ptr>=res.size())
{
++error;
std::cout<<">> [Lexer] line "<<line<<": this string must have a \' "<<str_begin<<" \' as its end."<<std::endl;
--ptr;
}
++ptr;
return token_str;
}
nasal_lexer::nasal_lexer()
{
token_list.clear();
detail_token_list.clear();
error=0;
return;
}
nasal_lexer::~nasal_lexer()
{
token_list.clear();
detail_token_list.clear();
return;
}
void nasal_lexer::delete_all_tokens()
{
token_list.clear();
detail_token_list.clear();
error=0;
return;
}
void nasal_lexer::print_token_list()
{
for(std::list<token>::iterator i=token_list.begin();i!=token_list.end();++i)
{
std::cout<<"line "<<i->line<<" ( ";
print_lexer_token(i->type);
std::cout<<" | "<<i->str<<" )"<<std::endl;
}
return;
}
void nasal_lexer::scanner(std::vector<char>& res)
{
token_list.clear();
detail_token_list.clear();
error=0;
int line=1;
std::string token_str;
int ptr=0;
while(ptr<res.size())
{
while(ptr<res.size() && (res[ptr]==' ' || res[ptr]=='\n' || res[ptr]=='\t' || res[ptr]=='\r' || res[ptr]<0))
{
if(res[ptr]=='\n')
++line;
++ptr;
}
if(ptr>=res.size())
break;
if(res[ptr]=='_' || ('a'<=res[ptr] && res[ptr]<='z') || ('A'<=res[ptr] && res[ptr]<='Z'))
{
token_str=identifier_gen(res,ptr,line);
token new_token;
new_token.line=line;
new_token.type=is_reserve_word(token_str);
new_token.str=token_str;
token_list.push_back(new_token);
}
else if('0'<=res[ptr] && res[ptr]<='9')
{
token_str=number_gen(res,ptr,line);
token new_token;
new_token.line=line;
new_token.type=__token_number;
new_token.str=token_str;
token_list.push_back(new_token);
}
else if(res[ptr]=='\'' || res[ptr]=='\"')
{
token_str=string_gen(res,ptr,line);
token new_token;
new_token.line=line;
new_token.type=__token_string;
new_token.str=token_str;
token_list.push_back(new_token);
}
else if(res[ptr]=='(' || res[ptr]==')' || res[ptr]=='[' || res[ptr]==']' || res[ptr]=='{' ||
res[ptr]=='}' || res[ptr]==',' || res[ptr]==';' || res[ptr]=='|' || res[ptr]==':' ||
res[ptr]=='?' || res[ptr]=='.' || res[ptr]=='`' || res[ptr]=='&' || res[ptr]=='@' ||
res[ptr]=='%' || res[ptr]=='$' || res[ptr]=='^' || res[ptr]=='\\')
{
token_str="";
token_str+=res[ptr];
token new_token;
new_token.line=line;
new_token.type=__token_operator;
new_token.str=token_str;
token_list.push_back(new_token);
++ptr;
}
else if(res[ptr]=='=' || res[ptr]=='+' || res[ptr]=='-' || res[ptr]=='*' || res[ptr]=='!' ||
res[ptr]=='/' || res[ptr]=='<' || res[ptr]=='>' || res[ptr]=='~')
{
// get calculation operator
token_str="";
token_str+=res[ptr];
++ptr;
if(ptr<res.size() && res[ptr]=='=')
{
token_str+=res[ptr];
++ptr;
}
token new_token;
new_token.line=line;
new_token.type=__token_operator;
new_token.str=token_str;
token_list.push_back(new_token);
}
else if(res[ptr]=='#')
{
// avoid note
while(ptr<res.size() && res[ptr]!='\n')
++ptr;
// after this process ptr will point to a '\n'
// don't ++ptr then the counter for line can work correctly
}
else
{
++error;
std::cout<<">> [Lexer] line "<<line<<": unknown char."<<std::endl;
++ptr;
}
}
std::cout<<">> [Lexer] complete scanning. "<<error<<" error(s)."<<std::endl;
return;
}
void nasal_lexer::generate_detail_token()
{
token detail_token;
detail_token_list.clear();
for(std::list<token>::iterator i=token_list.begin();i!=token_list.end();++i)
{
if(i->type==__token_number)
{
detail_token.line=i->line;
detail_token.str =i->str;
detail_token.type=__number;
detail_token_list.push_back(detail_token);
}
else if(i->type==__token_string)
{
detail_token.line=i->line;
detail_token.str =i->str;
detail_token.type=__string;
detail_token_list.push_back(detail_token);
}
else if(i->type==__token_reserve_word)
{
detail_token.line=i->line;
detail_token.str ="";
if (i->str=="for") detail_token.type=__for;
else if(i->str=="foreach") detail_token.type=__foreach;
else if(i->str=="forindex") detail_token.type=__forindex;
else if(i->str=="while") detail_token.type=__while;
else if(i->str=="var") detail_token.type=__var;
else if(i->str=="func") detail_token.type=__func;
else if(i->str=="break") detail_token.type=__break;
else if(i->str=="continue") detail_token.type=__continue;
else if(i->str=="return") detail_token.type=__return;
else if(i->str=="if") detail_token.type=__if;
else if(i->str=="else") detail_token.type=__else;
else if(i->str=="elsif") detail_token.type=__elsif;
else if(i->str=="nil") detail_token.type=__nil;
else if(i->str=="and") detail_token.type=__and_operator;
else if(i->str=="or") detail_token.type=__or_operator;
detail_token_list.push_back(detail_token);
}
else if(i->type==__token_identifier)
{
detail_token.line=i->line;
detail_token.str =i->str;
if(i->str.length()<=3)
detail_token.type=__id;
else
{
std::string tempstr=i->str;
int strback=tempstr.length()-1;
if(tempstr.length()>3 &&tempstr[strback]=='.' && tempstr[strback-1]=='.' && tempstr[strback-2]=='.')
{
detail_token.str="";
for(int j=0;j<tempstr.length()-3;++j)
detail_token.str+=tempstr[j];
detail_token.type=__dynamic_id;
}
else
detail_token.type=__id;
}
detail_token_list.push_back(detail_token);
}
else if(i->type==__token_operator)
{
detail_token.line=i->line;
detail_token.str ="";
if (i->str=="+") detail_token.type=__add_operator;
else if(i->str=="-") detail_token.type=__sub_operator;
else if(i->str=="*") detail_token.type=__mul_operator;
else if(i->str=="/") detail_token.type=__div_operator;
else if(i->str=="~") detail_token.type=__link_operator;
else if(i->str=="+=") detail_token.type=__add_equal;
else if(i->str=="-=") detail_token.type=__sub_equal;
else if(i->str=="*=") detail_token.type=__mul_equal;
else if(i->str=="/=") detail_token.type=__div_equal;
else if(i->str=="~=") detail_token.type=__link_equal;
else if(i->str=="=") detail_token.type=__equal;
else if(i->str=="==") detail_token.type=__cmp_equal;
else if(i->str=="!=") detail_token.type=__cmp_not_equal;
else if(i->str=="<") detail_token.type=__cmp_less;
else if(i->str=="<=") detail_token.type=__cmp_less_or_equal;
else if(i->str==">") detail_token.type=__cmp_more;
else if(i->str==">=") detail_token.type=__cmp_more_or_equal;
else if(i->str==";") detail_token.type=__semi;
else if(i->str==".") detail_token.type=__dot;
else if(i->str==":") detail_token.type=__colon;
else if(i->str==",") detail_token.type=__comma;
else if(i->str=="?") detail_token.type=__ques_mark;
else if(i->str=="!") detail_token.type=__nor_operator;
else if(i->str=="[") detail_token.type=__left_bracket;
else if(i->str=="]") detail_token.type=__right_bracket;
else if(i->str=="(") detail_token.type=__left_curve;
else if(i->str==")") detail_token.type=__right_curve;
else if(i->str=="{") detail_token.type=__left_brace;
else if(i->str=="}") detail_token.type=__right_brace;
else
{
++error;
std::cout<<">> [Lexer] line "<<detail_token.line<<": unknown operator \'"<<i->str<<"\'."<<std::endl;
detail_token.type=__unknown_operator;
}
detail_token_list.push_back(detail_token);
}
}
std::cout<<">> [Lexer] complete generating. "<<error<<" error(s)."<<std::endl;
return;
}
int nasal_lexer::get_error()
{
return error;
}
std::list<token>& nasal_lexer::get_detail_token_list()
{
return detail_token_list;
}
#endif
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