QParser2.c

#include <string.h>
#include <stdio.h>
char lineImage[1000];
int tokenPtr;

char lexer(){
    int len = strlen(lineImage);
    if (tokenPtr < len){
        tokenPtr++;
        return lineImage[tokenPtr];
    }
    else{
        printf("Exceeded maximum program size of %d\n", tokenPtr);
        return '*';
    }
}

int backup(){
    if(tokenPtr >= 0){
        tokenPtr--;
        return 1;
    }
    else{
        printf("Error in source program.\n");
        return 0;
    }
}

int STMT(){
    return 1;
}
int Q(){
    char c = lexer();
    if(c == '\n' || STMT()){
        return 1;
    }
    else{
        return 0;
    }
}

int pgm(){ //REPLACE THIS AND TEST IT

    char c = lexer();
    while(c != '\n') c = lexer();
    if(c == '\n'){
        printf("Found new line\n");
        c = lexer();
        if(STMT()){
            printf("Found stmt\n");
            if(Q()){
                printf("Found Q\n");
                return 1;
            }
        }
    }
    else{
        printf("c = %c\n", c);
        printf("Didn't find Q\n");
        return 0;
    }
    /**
        if(next token is '\n' || STMT || Q)
            return 1;
        else
            return 0;
    */
}



int main(int argc, char * argv[]){
    // if(argc == 1){
    //  printf("Need file");
    //  return 0;
    // }
    // if(argc == 2){

    // }

    FILE * file;
    file = fopen( "mac.mac" , "r");
    if(file == NULL){
        printf("Error");
        return 0;
    }

    char token;
    // strcpy(lineImage,"$");

    fgets(lineImage, 1000, file);

    tokenPtr = -1;
    // token = lexer();
    token = '$';
    if(pgm() && (token == '$')){
        printf("Parse found a pgm\n");
    }
    else{
        printf("Parse failed\n");
    }

    fclose(file);

    return 1;
}