641 lines
19 KiB
C++
641 lines
19 KiB
C++
#include <iostream>
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#include <vector>
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#include <fstream>
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#include <stdexcept>
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#include <tr1/memory>
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#include <stdlib.h>
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#include <string.h>
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namespace langkit {
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struct File_Position {
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int line;
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int column;
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// std::string::iterator text_pos;
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File_Position(int file_line, int file_column)
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: line(file_line), column(file_column) { }
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File_Position() : line(0), column(0) { }
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};
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struct Parse_Error {
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std::string reason;
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File_Position position;
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Parse_Error(const std::string &why, const File_Position &where) :
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reason(why), position(where) { }
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virtual ~Parse_Error() throw() {}
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};
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typedef std::tr1::shared_ptr<struct Token> TokenPtr;
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class Token_Type { public: enum Type { Internal_Match_Begin, Int, Id, Char, Str, Eol, Fun_Call, Arg_List, Variable, Equation, Var_Decl,
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Expression, Comparison, Additive, Multiplicative, Negate, Not }; };
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const char *token_type_to_string(int tokentype) {
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const char *token_types[] = { "Internal: match begin", "Int", "Id", "Char", "Str", "Eol", "Fun_Call", "Arg_List", "Variable", "Equation", "Var_Decl",
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"Expression", "Comparison", "Additive", "Multiplicative", "Negate", "Not" };
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return token_types[tokentype];
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}
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struct Token {
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std::string text;
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int identifier;
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const char *filename;
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File_Position start, end;
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std::vector<TokenPtr> children;
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Token(const std::string &token_text, int id, const char *fname) : text(token_text), identifier(id), filename(fname) { }
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Token(const std::string &token_text, int id, const char *fname, int start_line, int start_col, int end_line, int end_col) :
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text(token_text), identifier(id), filename(fname) {
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start.line = start_line;
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start.column = start_col;
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end.line = end_line;
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end.column = end_col;
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}
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};
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void debug_print(TokenPtr t, std::string prepend = "") {
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std::cout << prepend << "text: " << t->text << " id: " << token_type_to_string(t->identifier) << " pos: " << t->start.line << ", " << t->start.column << std::endl;
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for (unsigned int j = 0; j < t->children.size(); ++j) {
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debug_print(t->children[j], prepend + " ");
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}
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}
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class Parser {
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std::string::iterator input_pos, input_end;
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int line, col;
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std::string multiline_comment_begin, multiline_comment_end;
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std::string singleline_comment;
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char *filename;
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std::vector<TokenPtr> match_stack;
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public:
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void show_match_stack() {
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for (unsigned int i = 0; i < match_stack.size(); ++i) {
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debug_print(match_stack[i]);
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}
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}
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void clear_match_stack() {
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match_stack.clear();
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}
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void build_match(Token_Type::Type match_type, int match_start) {
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//so we want to take everything to the right of this and make them children
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TokenPtr t(new Token("", match_type, filename, match_stack[match_start]->start.line, match_stack[match_start]->start.column, line, col));
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t->children.assign(match_stack.begin() + (match_start), match_stack.end());
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match_stack.erase(match_stack.begin() + (match_start), match_stack.end());
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match_stack.push_back(t);
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}
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bool SkipComment() {
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bool retval = false;
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if (Str_(multiline_comment_begin.c_str())) {
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while (input_pos != input_end) {
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if (Str_(multiline_comment_end.c_str())) {
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break;
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}
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else if (!Eol_()) {
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++col;
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++input_pos;
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}
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}
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retval = true;
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}
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else if (Str_(singleline_comment.c_str())) {
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while (input_pos != input_end) {
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if (Eol_()) {
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break;
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}
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else {
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++col;
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++input_pos;
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}
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}
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retval = true;
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}
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return retval;
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}
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bool SkipWS() {
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bool retval = false;
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while (input_pos != input_end) {
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if ((*input_pos == ' ') || (*input_pos == '\t')) {
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++input_pos;
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++col;
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retval = true;
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}
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else if (SkipComment()) {
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retval = true;
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}
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else {
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break;
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}
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}
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return retval;
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}
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bool Int_() {
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bool retval = false;
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if ((input_pos != input_end) && (*input_pos >= '0') && (*input_pos <= '9')) {
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retval = true;
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while ((input_pos != input_end) && (*input_pos >= '0') && (*input_pos <= '9')) {
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++input_pos;
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++col;
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}
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}
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return retval;
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}
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bool Int(bool capture = false) {
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SkipWS();
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if (!capture) {
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return Int_();
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}
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else {
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std::string::iterator start = input_pos;
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int prev_col = col;
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int prev_line = line;
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if (Int_()) {
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std::string match(start, input_pos);
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TokenPtr t(new Token(match, Token_Type::Int, filename, prev_line, prev_col, line, col));
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match_stack.push_back(t);
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return true;
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}
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else {
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return false;
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}
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}
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}
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bool Id_() {
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bool retval = false;
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if ((input_pos != input_end) && (((*input_pos >= 'A') && (*input_pos <= 'Z')) || ((*input_pos >= 'a') && (*input_pos <= 'z')))) {
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retval = true;
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while ((input_pos != input_end) && (((*input_pos >= 'A') && (*input_pos <= 'Z')) || ((*input_pos >= 'a') && (*input_pos <= 'z')))) {
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++input_pos;
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++col;
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}
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}
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return retval;
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}
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bool Id(bool capture = false) {
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SkipWS();
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if (!capture) {
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return Id_();
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}
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else {
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std::string::iterator start = input_pos;
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int prev_col = col;
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int prev_line = line;
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if (Id_()) {
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std::string match(start, input_pos);
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TokenPtr t(new Token(match, Token_Type::Id, filename, prev_line, prev_col, line, col));
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match_stack.push_back(t);
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return true;
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}
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else {
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return false;
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}
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}
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}
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bool Char_(char c) {
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bool retval = false;
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if ((input_pos != input_end) && (*input_pos == c)) {
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++input_pos;
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++col;
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retval = true;
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}
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return retval;
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}
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bool Char(char c, bool capture = false) {
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SkipWS();
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if (!capture) {
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return Char_(c);
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}
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else {
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std::string::iterator start = input_pos;
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int prev_col = col;
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int prev_line = line;
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if (Char_(c)) {
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std::string match(start, input_pos);
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TokenPtr t(new Token(match, Token_Type::Char, filename, prev_line, prev_col, line, col));
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match_stack.push_back(t);
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return true;
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}
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else {
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return false;
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}
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}
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}
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bool Str_(const char *s) {
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bool retval = false;
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int len = strlen(s);
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if ((input_end - input_pos) >= len) {
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std::string::iterator tmp = input_pos;
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for (int i = 0; i < len; ++i) {
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if (*tmp != s[i]) {
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return false;
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}
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++tmp;
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}
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retval = true;
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input_pos = tmp;
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col += len;
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}
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return retval;
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}
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bool Str(const char *s, bool capture = false) {
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SkipWS();
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if (!capture) {
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return Str_(s);
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}
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else {
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std::string::iterator start = input_pos;
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int prev_col = col;
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int prev_line = line;
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if (Str_(s)) {
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std::string match(start, input_pos);
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TokenPtr t(new Token(match, Token_Type::Str, filename, prev_line, prev_col, line, col));
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match_stack.push_back(t);
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return true;
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}
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else {
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return false;
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}
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}
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}
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bool Eol_() {
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bool retval = false;
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if ((input_pos != input_end) && (Str_("\r\n") || Char_('\n'))) {
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retval = true;
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++line;
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col = 1;
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}
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else if ((input_pos != input_end) && Char_(';')) {
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retval = true;
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}
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return retval;
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}
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bool Eol(bool capture = false) {
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SkipWS();
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if (!capture) {
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return Eol_();
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}
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else {
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std::string::iterator start = input_pos;
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int prev_col = col;
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int prev_line = line;
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if (Eol_()) {
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std::string match(start, input_pos);
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TokenPtr t(new Token(match, Token_Type::Eol, filename, prev_line, prev_col, line, col));
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match_stack.push_back(t);
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return true;
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}
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else {
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return false;
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}
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}
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}
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bool Arg_List() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Expression()) {
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retval = true;
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if (Char(',')) {
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do {
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if (!Expression()) {
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throw Parse_Error("Unexpected value in parameter list", File_Position(line, col));
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}
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} while (retval && Char(','));
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}
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build_match(Token_Type::Arg_List, prev_stack_top);
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}
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return retval;
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}
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bool Fun_Or_Id() {
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bool retval = false;
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std::string::iterator prev_pos = input_pos;
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unsigned int prev_stack_top = match_stack.size();
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if (Id(true)) {
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retval = true;
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if (Char('(')) {
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Arg_List();
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if (!Char(')')) {
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throw Parse_Error("Incomplete function call", File_Position(line, col));
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}
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build_match(Token_Type::Fun_Call, prev_stack_top);
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}
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}
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return retval;
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}
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bool LHS() {
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if (Var_Decl() || Id()) {
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return true;
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}
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else {
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return false;
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}
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}
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bool Var_Decl() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Str("var")) {
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retval = true;
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if (!Id(true)) {
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throw Parse_Error("Incomplete variable declaration", File_Position(line, col));
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}
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build_match(Token_Type::Var_Decl, prev_stack_top);
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}
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return retval;
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}
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bool Value() {
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if (Fun_Or_Id() || Int(true) || Negate() || Not()) {
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return true;
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}
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else {
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return false;
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}
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}
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bool Negate() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Char('-')) {
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retval = true;
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if (!Additive()) {
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throw Parse_Error("Incomplete negation expression", File_Position(line, col));
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}
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build_match(Token_Type::Negate, prev_stack_top);
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}
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return retval;
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}
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bool Not() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Char('!')) {
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retval = true;
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if (!Expression()) {
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throw Parse_Error("Incomplete '!' expression", File_Position(line, col));
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}
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build_match(Token_Type::Not, prev_stack_top);
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}
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return retval;
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}
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bool Comparison() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Additive()) {
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retval = true;
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if (Str(">=", true) || Char('>', true) || Str("<=", true) || Char('<', true) || Str("==", true) || Str("!=", true)) {
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do {
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if (!Additive()) {
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throw Parse_Error("Incomplete comparison expression", File_Position(line, col));
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}
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} while (retval && (Str(">=", true) || Char('>', true) || Str("<=", true) || Char('<', true) || Str("==", true) || Str("!=", true)));
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build_match(Token_Type::Comparison, prev_stack_top);
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}
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}
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return retval;
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}
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bool Additive() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Multiplicative()) {
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retval = true;
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if (Char('+', true) || Char('-', true)) {
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do {
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if (!Multiplicative()) {
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throw Parse_Error("Incomplete math expression", File_Position(line, col));
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}
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} while (retval && (Char('+', true) || Char('-', true)));
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build_match(Token_Type::Additive, prev_stack_top);
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}
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}
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return retval;
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}
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bool Multiplicative() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Value()) {
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retval = true;
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if (Char('*', true) || Char('/', true)) {
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do {
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if (!Value()) {
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throw Parse_Error("Incomplete math expression", File_Position(line, col));
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}
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} while (retval && (Char('*', true) || Char('/', true)));
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build_match(Token_Type::Multiplicative, prev_stack_top);
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}
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}
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return retval;
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}
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bool Expression() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Comparison()) {
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retval = true;
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if (Str("&&", true) || Str("||", true)) {
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do {
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if (!Comparison()) {
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throw Parse_Error("Incomplete expression", File_Position(line, col));
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}
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} while (retval && (Str("&&", true) || Str("||", true)));
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build_match(Token_Type::Expression, prev_stack_top);
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}
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}
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return retval;
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}
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bool Equation() {
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bool retval = false;
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int prev_stack_top = match_stack.size();
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if (Expression()) {
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retval = true;
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if (Char('=', true)) {
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do {
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if (!Expression()) {
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throw Parse_Error("Incomplete math expression", File_Position(line, col));
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}
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} while (retval && (Char('=', true)));
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build_match(Token_Type::Equation, prev_stack_top);
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}
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}
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return retval;
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}
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bool Statement() {
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if (Equation() || Expression()) {
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if (Eol()) {
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return true;
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}
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else {
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return false;
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}
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}
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return false;
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}
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bool Statements() {
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bool retval = false;
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while (Statement() || Eol()) { }
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if (input_pos == input_end) {
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retval = true;
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}
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return retval;
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}
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bool parse(std::string input) {
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input_pos = input.begin();
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input_end = input.end();
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line = 1; col = 1;
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multiline_comment_begin = "/*";
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multiline_comment_end = "*/";
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singleline_comment = "//";
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return Statements();
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}
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};
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};
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std::string load_file(const char *filename) {
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std::ifstream infile (filename, std::ios::in | std::ios::ate);
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if (!infile.is_open()) {
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std::string fname = filename;
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throw std::runtime_error("Can not open: " + fname);
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}
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std::streampos size = infile.tellg();
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infile.seekg(0, std::ios::beg);
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std::vector<char> v(size);
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infile.read(&v[0], size);
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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;
|
|
}
|