654 lines
19 KiB
C++
654 lines
19 KiB
C++
#include <iostream>
|
|
#include <vector>
|
|
#include <fstream>
|
|
#include <stdexcept>
|
|
#include <tr1/memory>
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
namespace langkit {
|
|
struct File_Position {
|
|
int line;
|
|
int column;
|
|
std::string::iterator text_pos;
|
|
|
|
File_Position(int file_line, int file_column)
|
|
: line(file_line), column(file_column) { }
|
|
|
|
File_Position() : line(0), column(0) { }
|
|
};
|
|
|
|
struct Parse_Error {
|
|
std::string reason;
|
|
File_Position position;
|
|
|
|
Parse_Error(const std::string &why, const File_Position &where) :
|
|
reason(why), position(where) { }
|
|
|
|
virtual ~Parse_Error() throw() {}
|
|
};
|
|
|
|
typedef std::tr1::shared_ptr<struct Token> TokenPtr;
|
|
|
|
class Token_Type { public: enum Type { Internal_Match_Begin, Int, Id, Char, Str, Eol, Fun_Call, Arg_List, Variable, Equation, Var_Decl,
|
|
Expression, Comparison, Additive, Multiplicative, Negate, Not }; };
|
|
|
|
const char *token_type_to_string(int tokentype) {
|
|
const char *token_types[] = { "Internal: match begin", "Int", "Id", "Char", "Str", "Eol", "Fun_Call", "Arg_List", "Variable", "Equation", "Var_Decl",
|
|
"Expression", "Comparison", "Additive", "Multiplicative", "Negate", "Not" };
|
|
|
|
return token_types[tokentype];
|
|
}
|
|
|
|
struct Token {
|
|
std::string text;
|
|
int identifier;
|
|
const char *filename;
|
|
File_Position start, end;
|
|
|
|
std::vector<TokenPtr> children;
|
|
|
|
Token(const std::string &token_text, int id, const char *fname) : text(token_text), identifier(id), filename(fname) { }
|
|
Token(const std::string &token_text, int id, const char *fname, int start_line, int start_col, int end_line, int end_col) :
|
|
text(token_text), identifier(id), filename(fname) {
|
|
|
|
start.line = start_line;
|
|
start.column = start_col;
|
|
end.line = end_line;
|
|
end.column = end_col;
|
|
}
|
|
};
|
|
|
|
void debug_print(TokenPtr t, std::string prepend = "") {
|
|
std::cout << prepend << "text: " << t->text << " id: " << token_type_to_string(t->identifier) << " pos: " << t->start.line << ", " << t->start.column << std::endl;
|
|
for (unsigned int j = 0; j < t->children.size(); ++j) {
|
|
debug_print(t->children[j], prepend + " ");
|
|
}
|
|
}
|
|
|
|
class Parser {
|
|
std::string::iterator input_pos, input_end;
|
|
int line, col;
|
|
std::string multiline_comment_begin, multiline_comment_end;
|
|
std::string singleline_comment;
|
|
char *filename;
|
|
std::vector<TokenPtr> match_stack;
|
|
|
|
public:
|
|
void show_match_stack() {
|
|
for (unsigned int i = 0; i < match_stack.size(); ++i) {
|
|
debug_print(match_stack[i]);
|
|
}
|
|
}
|
|
|
|
void clear_match_stack() {
|
|
match_stack.clear();
|
|
}
|
|
|
|
bool Start_Parse() {
|
|
TokenPtr t(new Token("", Token_Type::Internal_Match_Begin, filename));
|
|
match_stack.push_back(t);
|
|
t->start.line = line;
|
|
t->start.column = col;
|
|
t->start.text_pos = input_pos;
|
|
|
|
return true;
|
|
}
|
|
|
|
void Fail_Parse() {
|
|
TokenPtr t = match_stack.back(); match_stack.pop_back();
|
|
while (t->identifier != Token_Type::Internal_Match_Begin) {
|
|
t = match_stack.back(); match_stack.pop_back();
|
|
}
|
|
line = t->start.line;
|
|
col = t->start.column;
|
|
input_pos = t->start.text_pos;
|
|
}
|
|
|
|
bool Finish_Parse(int id) {
|
|
for (int i = (int)match_stack.size() - 1; i >= 0; --i) {
|
|
if (match_stack[i]->identifier == Token_Type::Internal_Match_Begin) {
|
|
//so we want to take everything to the right of this and make them children
|
|
match_stack[i]->children.insert(match_stack[i]->children.begin(), match_stack.begin() + (i+1), match_stack.end());
|
|
//match_stack[i]->children.assign(match_stack.begin() + (i+1), match_stack.end());
|
|
match_stack.erase(match_stack.begin() + (i+1), match_stack.end());
|
|
match_stack[i]->identifier = id;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
throw Parse_Error("Could not find internal begin parse marker", File_Position());
|
|
return false;
|
|
}
|
|
|
|
bool SkipComment() {
|
|
bool retval = false;
|
|
|
|
if (Str_(multiline_comment_begin.c_str())) {
|
|
while (input_pos != input_end) {
|
|
if (Str_(multiline_comment_end.c_str())) {
|
|
break;
|
|
}
|
|
else if (!Eol_()) {
|
|
++col;
|
|
++input_pos;
|
|
}
|
|
}
|
|
retval = true;
|
|
}
|
|
else if (Str_(singleline_comment.c_str())) {
|
|
while (input_pos != input_end) {
|
|
if (Eol_()) {
|
|
break;
|
|
}
|
|
else {
|
|
++col;
|
|
++input_pos;
|
|
}
|
|
}
|
|
retval = true;
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
bool SkipWS() {
|
|
bool retval = false;
|
|
while (input_pos != input_end) {
|
|
if ((*input_pos == ' ') || (*input_pos == '\t')) {
|
|
++input_pos;
|
|
++col;
|
|
retval = true;
|
|
}
|
|
else if (SkipComment()) {
|
|
retval = true;
|
|
}
|
|
else {
|
|
break;
|
|
}
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
bool Int_() {
|
|
bool retval = false;
|
|
if ((input_pos != input_end) && (*input_pos >= '0') && (*input_pos <= '9')) {
|
|
retval = true;
|
|
while ((input_pos != input_end) && (*input_pos >= '0') && (*input_pos <= '9')) {
|
|
++input_pos;
|
|
++col;
|
|
}
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
bool Int(bool capture = false) {
|
|
SkipWS();
|
|
|
|
if (!capture) {
|
|
return Int_();
|
|
}
|
|
else {
|
|
std::string::iterator start = input_pos;
|
|
int prev_col = col;
|
|
int prev_line = line;
|
|
if (Int_()) {
|
|
std::string match(start, input_pos);
|
|
TokenPtr t(new Token(match, Token_Type::Int, filename, prev_col, prev_line, col, line));
|
|
/*
|
|
t->start.column = prev_col;
|
|
t->start.line = prev_line;
|
|
t->end.column = col;
|
|
t->end.line = line;*/
|
|
match_stack.push_back(t);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool Id_() {
|
|
bool retval = false;
|
|
if ((input_pos != input_end) && (((*input_pos >= 'A') && (*input_pos <= 'Z')) || ((*input_pos >= 'a') && (*input_pos <= 'z')))) {
|
|
retval = true;
|
|
while ((input_pos != input_end) && (((*input_pos >= 'A') && (*input_pos <= 'Z')) || ((*input_pos >= 'a') && (*input_pos <= 'z')))) {
|
|
++input_pos;
|
|
++col;
|
|
}
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
bool Id(bool capture = false) {
|
|
SkipWS();
|
|
|
|
if (!capture) {
|
|
return Id_();
|
|
}
|
|
else {
|
|
std::string::iterator start = input_pos;
|
|
int prev_col = col;
|
|
int prev_line = line;
|
|
if (Id_()) {
|
|
std::string match(start, input_pos);
|
|
TokenPtr t(new Token(match, Token_Type::Id, filename, prev_col, prev_line, col, line));
|
|
/*
|
|
t->start.column = prev_col;
|
|
t->start.line = prev_line;
|
|
t->end.column = col;
|
|
t->end.line = line; */
|
|
match_stack.push_back(t);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool Char_(char c) {
|
|
bool retval = false;
|
|
if ((input_pos != input_end) && (*input_pos == c)) {
|
|
++input_pos;
|
|
++col;
|
|
retval = true;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
bool Char(char c, bool capture = false) {
|
|
SkipWS();
|
|
|
|
if (!capture) {
|
|
return Char_(c);
|
|
}
|
|
else {
|
|
std::string::iterator start = input_pos;
|
|
int prev_col = col;
|
|
int prev_line = line;
|
|
if (Char_(c)) {
|
|
std::string match(start, input_pos);
|
|
TokenPtr t(new Token(match, Token_Type::Char, filename, prev_col, prev_line, col, line));
|
|
/*
|
|
t->start.column = prev_col;
|
|
t->start.line = prev_line;
|
|
t->end.column = col;
|
|
t->end.line = line; */
|
|
match_stack.push_back(t);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool Str_(const char *s) {
|
|
bool retval = false;
|
|
int len = strlen(s);
|
|
|
|
if ((input_end - input_pos) >= len) {
|
|
std::string::iterator tmp = input_pos;
|
|
for (int i = 0; i < len; ++i) {
|
|
if (*tmp != s[i]) {
|
|
return false;
|
|
}
|
|
++tmp;
|
|
}
|
|
retval = true;
|
|
input_pos = tmp;
|
|
col += len;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
bool Str(const char *s, bool capture = false) {
|
|
SkipWS();
|
|
|
|
if (!capture) {
|
|
return Str_(s);
|
|
}
|
|
else {
|
|
std::string::iterator start = input_pos;
|
|
int prev_col = col;
|
|
int prev_line = line;
|
|
if (Str_(s)) {
|
|
std::string match(start, input_pos);
|
|
TokenPtr t(new Token(match, Token_Type::Str, filename, prev_col, prev_line, col, line));
|
|
/*
|
|
t->start.column = prev_col;
|
|
t->start.line = prev_line;
|
|
t->end.column = col;
|
|
t->end.line = line; */
|
|
match_stack.push_back(t);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool Eol_() {
|
|
bool retval = false;
|
|
|
|
if ((input_pos != input_end) && (Str_("\r\n") || Char_('\n'))) {
|
|
retval = true;
|
|
++line;
|
|
col = 1;
|
|
}
|
|
else if ((input_pos != input_end) && Char_(';')) {
|
|
retval = true;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
bool Eol(bool capture = false) {
|
|
SkipWS();
|
|
|
|
if (!capture) {
|
|
return Eol_();
|
|
}
|
|
else {
|
|
std::string::iterator start = input_pos;
|
|
int prev_col = col;
|
|
int prev_line = line;
|
|
if (Eol_()) {
|
|
std::string match(start, input_pos);
|
|
TokenPtr t(new Token(match, Token_Type::Eol, filename, prev_col, prev_line, col, line));
|
|
/*
|
|
t->start.column = prev_col;
|
|
t->start.line = prev_line;
|
|
t->end.column = col;
|
|
t->end.line = line; */
|
|
match_stack.push_back(t);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool Arg_List() {
|
|
bool retval;
|
|
|
|
Start_Parse();
|
|
|
|
retval = Expression();
|
|
while (retval && Char(',')) {
|
|
retval = Expression();
|
|
if (!retval) {
|
|
throw Parse_Error("Unexpected value in parameter list", File_Position(line, col));
|
|
}
|
|
}
|
|
|
|
if (retval) {
|
|
Finish_Parse(Token_Type::Arg_List);
|
|
}
|
|
else {
|
|
Fail_Parse();
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
bool Fun_Call() {
|
|
Start_Parse();
|
|
|
|
if (Id(true) && Char('(') && (Arg_List() || true) && Char(')')) {
|
|
Finish_Parse(Token_Type::Fun_Call);
|
|
return true;
|
|
}
|
|
else {
|
|
Fail_Parse();
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool LHS() {
|
|
if (Var_Decl() || Id()) {
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool Var_Decl() {
|
|
Start_Parse();
|
|
|
|
if (Str("var") && Id(true)) {
|
|
Finish_Parse(Token_Type::Var_Decl);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool Value() {
|
|
if (Fun_Call() || Int(true) || Id(true) || Negate() || Not()) {
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool Negate() {
|
|
Start_Parse();
|
|
|
|
if (Char('-') && Additive()) {
|
|
Finish_Parse(Token_Type::Negate);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool Not() {
|
|
Start_Parse();
|
|
|
|
if (Char('!') && Expression()) {
|
|
Finish_Parse(Token_Type::Not);
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool Comparison() {
|
|
bool retval;
|
|
|
|
Start_Parse();
|
|
|
|
retval = Additive();
|
|
while (retval && (Str(">=", true) || Char('>', true) || Str("<=", true) || Char('<', true) || Str("==", true) || Str("!=", true))) {
|
|
retval = Additive();
|
|
}
|
|
|
|
if (retval) {
|
|
Finish_Parse(Token_Type::Comparison);
|
|
}
|
|
else {
|
|
Fail_Parse();
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
bool Additive() {
|
|
bool retval;
|
|
|
|
Start_Parse();
|
|
|
|
retval = Multiplicative();
|
|
while (retval && (Char('+', true) || Char('-', true))) {
|
|
retval = Multiplicative();
|
|
}
|
|
|
|
if (retval) {
|
|
Finish_Parse(Token_Type::Additive);
|
|
}
|
|
else {
|
|
Fail_Parse();
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
bool Multiplicative() {
|
|
bool retval;
|
|
|
|
Start_Parse();
|
|
|
|
retval = Value();
|
|
while (retval && (Char('*', true) || Char('/', true))) {
|
|
retval = Value();
|
|
}
|
|
|
|
if (retval) {
|
|
Finish_Parse(Token_Type::Multiplicative);
|
|
}
|
|
else {
|
|
Fail_Parse();
|
|
}
|
|
|
|
/*
|
|
* The above can be shortened to this, but let's not get carried away :)
|
|
if (!(Start_Parse() && Id(true) && Char('(') && (Arg_List() || true) && Char(')') && Finish_Parse(Token_Type::Fun_Call))) {
|
|
Fail_Parse();
|
|
}
|
|
*/
|
|
|
|
return retval;
|
|
}
|
|
|
|
bool Expression() {
|
|
bool retval;
|
|
|
|
Start_Parse();
|
|
|
|
retval = Comparison();
|
|
while (retval && (Str("&&", true) || Str("||", true))) {
|
|
retval = Comparison();
|
|
}
|
|
|
|
if (retval) {
|
|
Finish_Parse(Token_Type::Expression);
|
|
}
|
|
else {
|
|
Fail_Parse();
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
bool Equation() {
|
|
Start_Parse();
|
|
if (LHS() && Char('=') && Expression()) {
|
|
Finish_Parse(Token_Type::Equation);
|
|
return true;
|
|
}
|
|
else {
|
|
Fail_Parse();
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool Statement() {
|
|
if (Equation() || Expression()) {
|
|
if (Eol()) {
|
|
return true;
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool Statements() {
|
|
bool retval = false;
|
|
while (Statement() || Eol()) { }
|
|
|
|
if (input_pos == input_end) {
|
|
retval = true;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
bool parse(std::string input) {
|
|
input_pos = input.begin();
|
|
input_end = input.end();
|
|
line = 1; col = 1;
|
|
multiline_comment_begin = "/*";
|
|
multiline_comment_end = "*/";
|
|
singleline_comment = "//";
|
|
|
|
return Statements();
|
|
}
|
|
};
|
|
};
|
|
|
|
std::string load_file(const char *filename) {
|
|
std::ifstream infile (filename, std::ios::in | std::ios::ate);
|
|
|
|
if (!infile.is_open()) {
|
|
std::string fname = filename;
|
|
throw std::runtime_error("Can not open: " + fname);
|
|
}
|
|
|
|
std::streampos size = infile.tellg();
|
|
infile.seekg(0, std::ios::beg);
|
|
|
|
std::vector<char> v(size);
|
|
infile.read(&v[0], size);
|
|
|
|
std::string ret_val (v.empty() ? std::string() : std::string (v.begin(), v.end()).c_str());
|
|
|
|
return ret_val;
|
|
}
|
|
|
|
int main(int argc, char *argv[]) {
|
|
langkit::Parser parser;
|
|
std::string input;
|
|
|
|
if (argc > 1) {
|
|
try {
|
|
std::cout << parser.parse(load_file(argv[1])) << std::endl;
|
|
parser.show_match_stack();
|
|
}
|
|
catch (langkit::Parse_Error &pe) {
|
|
std::cout << pe.reason << " at " << pe.position.line << ", " << pe.position.column << std::endl;
|
|
parser.clear_match_stack();
|
|
}
|
|
}
|
|
else {
|
|
std::cout << "eval> ";
|
|
std::getline(std::cin, input);
|
|
while (input != "quit") {
|
|
try {
|
|
std::cout << parser.parse(input) << std::endl;
|
|
parser.show_match_stack();
|
|
parser.clear_match_stack();
|
|
}
|
|
catch (langkit::Parse_Error &pe) {
|
|
std::cout << pe.reason << " at " << pe.position.line << ", " << pe.position.column << std::endl;
|
|
parser.clear_match_stack();
|
|
}
|
|
std::cout << "eval> ";
|
|
std::getline(std::cin, input);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|