Token.h

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#pragma once
#include "util/Utilities.h"
#include <map>
#include <memory>
#include <string>

 
namespace sammine_lang {
enum TokenType {
  // TODO: Add void keyword for return.
  // Also might have to add a !=, ++i, --i
  TokADD, // +
  TokSUB, // -
  TokMUL, // *
  TokDIV, // /
  TokMOD, // %
 
  TokAddAssign, // +=
  TokAddIncr,   // ++
  TokSubAssign, // -=
  TokSubDecr,   // --
  TokMulAssign, // *=
  TokDivAssign, // /=
 
  TokAND,        // &&
  TokAndLogical, // &
  TokOR,         // ||
  TokORLogical,  // |
  TokXOR,        // ^
  TokSHL,        // <<
  TokSHR,        // >>
 
  TokEQUAL,     // ==
  TokLESS,      // <
  TokLessEqual, // <=
 
  TokGREATER,      // >
  TokGreaterEqual, // >=
 
  TokASSIGN, // =
  TokNOT,    // !
 
  // TokEXP AND FloorDiv
  TokEXP,      // **
  TokFloorDiv, // /_
  TokCeilDiv,  // /^
 
  // TokPAREN
  TokLeftParen,  // (
  TokRightParen, // )
  TokLeftCurly,  // {
  TokRightCurly, // }
 
  // Comma and colons and all that
  TokComma,       // ,
  TokDot,         // .
  TokSemiColon,   // ;
  TokColon,       // :
  TokDoubleColon, // ::
 
  // TokFunction
  TokReturn,
  TokFunc,   // fn
  TokRecord, // record
  TokArrow,  // ->
  TokLet,    // let
  TokExtern, // extern
  // TokID
  TokID,  // Representing an identifier
  TokStr, // Representing a string
  // TokNum
  TokNum,   // Representing a number
  TokTrue,  // Representing a boolean true
  TokFalse, // Representing a boolean false
  // TokIf
  TokIf,   // if
  TokElse, // else
 
  // TokCOMMENTS
  TokSingleComment, //
  TokEOF,
  TokINVALID,
};
 
static const std::map<TokenType, std::string> TokenMap = {
    {TokADD, "+"},
    {TokSUB, "-"},
    {TokMUL, "*"},
    {TokDIV, "/"},
    {TokMOD, "%"},
 
    {TokAddAssign, "+="},
    {TokAddIncr, "++"},
    {TokSubAssign, "-="},
    {TokSubDecr, "--"},
    {TokMulAssign, "*="},
    {TokDivAssign, "/="},
 
    {TokAND, "&&"},
    {TokAndLogical, "&"},
    {TokOR, "||"},
    {TokORLogical, "|"},
    {TokXOR, "^"},
    {TokSHL, ">>"},
    {TokSHR, "<<"},
    {TokEQUAL, "=="},
    {TokLESS, "<"},
    {TokLessEqual, "<="},
 
    {TokGREATER, ">"},
    {TokGreaterEqual, ">="},
 
    {TokASSIGN, "="},
    {TokNOT, "!"},
    {TokEXP, "**"},
    {TokFloorDiv, "/_"},
    {TokCeilDiv, "/^"},
 
    {TokLeftParen, "("},
    {TokRightParen, ")"},
    {TokLeftCurly, "{"},
    {TokRightCurly, "}"},
 
    {TokComma, ","},
    {TokDot, "."},
    {TokSemiColon, ";"},
    {TokColon, ":"},
    {TokDoubleColon, "::"},
 
    // TokFunction
    {TokReturn, "return"},
    {TokFunc, "fn"},
    {TokArrow, "->"},
    {TokLet, "let"},
    {TokRecord, "Record"},
    {TokID, "identifier"},
 
    {TokNum, "number"},
 
    {TokIf, "if"},
    {TokElse, "else"},
 
    // TokCOMMENTS
    {TokSingleComment, "#"},
    {TokEOF, "EOF"},
    {TokINVALID, "UNRECOGNIZED"},
};


class Token {
  using Location = sammine_util::Location;
 
public:
  TokenType tok_type;
  std::string lexeme;
  Location location;
  Token() = delete;
  Token(TokenType type, std::string lexeme, Location location)
      : tok_type(type), lexeme(std::move(lexeme)), location(location) {}
  bool is_comparison() {
    return tok_type == TokLESS || tok_type == TokGreaterEqual ||
           tok_type == TokLessEqual || tok_type == TokGREATER ||
           tok_type == TokEQUAL;
  }
  bool is_logical() { return tok_type == TokOR || tok_type == TokAND; }
  Location get_location() const { return this->location; }
};


class TokenStream {
  std::vector<std::shared_ptr<Token>> TokStream;
  size_t current_index;
  bool error;
 
public:
  std::vector<std::shared_ptr<Token>> ErrStream;
 
  TokenStream() : TokStream(), current_index(0), error(false) {}
 
  void push_back(const std::shared_ptr<Token> &token) {
    if (token->tok_type == TokINVALID) {
      error = true;
      ErrStream.push_back(token);
    } else {
      TokStream.push_back(token);
    }
  }
 
  bool hasErrors() { return error; }
 
  void push_back(const Token &token) {
    this->push_back(std::make_shared<Token>(token));
  }
 
  std::shared_ptr<Token> &exhaust_until(TokenType tokType) {
    if (tokType == TokenType::TokEOF) {
      current_index = TokStream.size() - 1;
      return TokStream.back();
    }
    while (!isEnd()) {
      if (TokStream[current_index]->tok_type == tokType)
        return TokStream[current_index++];
      else
        current_index++;
    }
 
    return TokStream.back();
  }
 
  bool isEnd() { return current_index >= (TokStream.size() - 1); }
  std::shared_ptr<Token> peek() { return TokStream[current_index]; };
  std::shared_ptr<Token> consume() {
    auto token = peek();
    current_index = std::min(TokStream.size() - 1, current_index + 1);
    return token;
  }
 
  sammine_util::Location currentLocation() {
    if (!TokStream.empty()) {
      return TokStream[current_index]->get_location();
    }
    return {};
  }
};
} // namespace sammine_lang