BOLT Programming Source code

#ifndef INPUT_H_INCLUDED
#define INPUT_H_INCLUDED

FILE* Input;
char LookChar = '\0';

string Value;
int    Token;
bool DoScan = true;// Determins whether or not we should scan

// All of the keywords used in the program
string Keyword[] = {"begin", "end", "main", "number",// Look up
                    "text", "for", "loop", "while", "until",// Look up
                    "do", "forever", "if", "else", "break",// Look up
                    "continue", "asm", "switch", "case",// Look up
                    "return", "datatype", "list", "void",
                    "length", "value", "sizeof", "from", "to", "noreturn",
                    "nohalt"};// Look up
#include "Tokens.h"

void ReadChar(void) {
    LookChar = fgetc(Input);
    if(LookChar == '\n') {// If we found a newline
        LineNum++;// Increment the line that we are on
    }// End of If statement
}

void GetChar(void) {
    if(TempChar != ' ') {
        LookChar = TempChar;
        TempChar = ' ';
    } else {
        ReadChar();
        if(LookChar == '/') {
            TempChar = fgetc(Input);
            if (TempChar == '*') {// Now, if the temporary character is a astric sign
                LookChar = $BlocCom; // Show we found a block comment
                TempChar = ' '; // Clear the temporary character
            // Now, if the temporary character is a slash
            } else if (TempChar == '/') {// Look up
                LookChar = $LineCom; // Show we found a Line comment
                TempChar = ' '; // Clear the temporary character
            } else {// If we dont need the next character
                fseek(Input,-1,SEEK_CUR);
                TempChar = ' ';
            }// End of If statement
        }
    }
}

// Skips all block comments found in the code
void SkipBlock(void) {// Look up
    do {// Loop while we have not found the ending '/'
        do {// Loop while we have not found the beggining '*'
            GetChar();// Read the next character
            // if there is a comment inside of another, allow it
            if (LookChar == $BlocCom) SkipBlock();// Look up
        } while (LookChar != '*');// Loop while we havent found a '*'
        GetChar();// Get the next character
    } while (LookChar != '/');// Loop until the end of the comment is found
    GetChar();// Skip the ending '/'
}// End of SkipBLock(void)

// Skips all line comments found in the code
void SkipLine(void) {// Look up
    do {// Loop until we found the newline character
        ReadChar();// Skip the next character
    } while ((LookChar != '\n')&&(LookChar != EOF));// Until we we find the end of the line
    ReadChar();// Skip that character
}// End of SkipLine(void)

void SkipWhite(void) {
    while((LookChar == ' ') || (LookChar == '\t') ||
          (LookChar == '\n') || (LookChar == '\r') ||
          (LookChar == $BlocCom) ||
          (LookChar == $LineCom) || (LookChar == EOF)) {
            if(LookChar == $BlocCom) {// If we found a block comment
                SkipBlock();// Skip the block comment
            } else if(LookChar == $LineCom) {// Or if we found a line comment
                SkipLine();// Skip the line comment
            } else if(LookChar == EOF) {
                break;
            } else {
                GetChar();
            }
        }
}

void Match(string c) {
    if(LookChar == c.c_str()[0]) {
        GetChar();
        SkipWhite();
    } else Expected("\""+c+"\"",ERROR_MATCH);
}

void MatchStr(string Str) {
    if(Value != Str) {
        Expected("\""+Str+"\"",ERROR_MATCH);
    }
}

string GetName(bool Skip = true) {
    if(!isalpha(LookChar)) Expected("Name",ERROR_ID);
    Value = "";
    while(isalpha(LookChar) || isdigit(LookChar) || (LookChar=='_')) {
        Value += LookChar;
        ReadChar();
    }
//    if (Lookup(Value) == 0) {// Look up
//        Token = $identifier;// The identifier is not a reserved word
//    } else {// If it is a reserved word
//        Token = Lookup(Value);// The keyword is not an identifier
//    }// End of If statement
    if(Skip) SkipWhite();
    return Value;
}

string GetNum(void) {
    if((!isdigit(LookChar))&&(LookChar!='-')) Expected("Number",ERROR_NUMBER);
    Value = "";
    if(LookChar=='-') {
        Value += LookChar;
        GetChar();
    }
    while(isdigit(LookChar)) {
        Value += LookChar;
        GetChar();
    }
    if(LookChar == '.') {
        Value += LookChar;
        GetChar();
        if(!isdigit(LookChar)) Expected("Valid Decimal Number",ERROR_NUMBER);
        while(isdigit(LookChar)) {
            Value += LookChar;
            GetChar();
        }
    }
    Token = $DT_number;
    SkipWhite();
    return Value;
}

// Get a string from the file
string GetString(void) {// Look up
    Value = "";// Clear the value
    int Curr_Line = LineNum;// Save the line number
    if(LookChar == '\"') {// If we started the string
        ReadChar();// Get the next character
    } else {// If we did not start the string
        Abort("Invalid string",ERROR_STR);// Report the error
    }// End of IF statement
    Value = "\"";// Add the begining of the string
    while(LookChar != '\"') {// While we are still in the string
        switch(LookChar) {// Process the next character
            case EOF:// If we hit the end of the file
                LineNum=Curr_Line;// reset the line number
                Abort("You did not end your string",ERROR_STR);// Report the error
                break;// Leave the switch statement
            case '\n':// IF we found a newline
                SkipWhite();// Skip the whitespace
                break;// Leave the switch statement
            default:// If we found a regular character
                Value+=LookChar;// add it to the string
                GetChar();// Read the next character
        }// End of Switch statement
    }// End of While loop
    Value+=LookChar;// Add the ending of the string
    Match("\"");// Make sure we ended it
    Token = $DT_string;// Show that we found a string
    return Value;// Return the string
}// End of GetString(void)

#endif // INPUT_H_INCLUDED