#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


char var_eof[2] = {-1, 0};
char var_eol[2] = {10, 0};
char var_quote[2] = {34, 0};
char var_false[1] = {0};
char var_true[2] = {'1', 0};


char * eq(char * a, char * b)
{
    return (strcmp(a, b) == 0) ? var_true : var_false;
}

char * lt(char * a, char * b)
{
    return (strcmp(a, b) < 0) ? var_true : var_false;
}
char * not(char * a)
{
    return (strcmp(a, var_true) != 0) ? var_true : var_false;
}

char * addstringchar(char * str, char * chr)
{
    int str_len = strlen(str);
    assert(strlen(chr) == 1);
    char * res = malloc((str_len + 2) * sizeof(char));
    strcpy(res, str);
    res[str_len + 0] = chr[0];
    res[str_len + 1] = 0;
    return res;
}

char * emit(char * str)
{
    fputs(str, stdout);
    return 0;
}

char * trace(char * var_name, char * var_value)
{
    const char * env_trace = getenv("TRACE");
    if( !env_trace ) return 0;
    fputs(var_name, stderr);
    fputs("=", stderr);
    fputs(var_value, stderr);
    fputs(var_eol, stderr);
    return 0;
}

int LINE = 1;

char * peek()
{
    char * res = malloc(2*sizeof(char));
    res[0] = getc(stdin);
    res[1] = 0;
    ungetc(res[0], stdin);
    return res;
}

void skip()
{
    char c = getc(stdin);
    if( c == 10 ) LINE += 1;
}

void skipchar(char * chr)
{
    assert(strlen(chr) == 1);
    char * act = peek();
    assert(strlen(act) == 1);
    if( chr[0] == act[0] ) {skip(); return;};
    fprintf(stderr, "Expected '%c' on line %d but saw '%c' instead\n", chr[0], LINE, act[0]);
    exit(1);
}

char * fileget(char * var_path)
{
	FILE * file_ptr;
	int file_size;
	char * res;

	file_ptr = fopen(var_path, "r");
	if( NULL == file_ptr ) {
	    fprintf(stderr, "Could not load file %s", var_path);
    	exit(1);
	}

	fseek(file_ptr, 0, SEEK_END);
	file_size = ftell(file_ptr);
	fseek(file_ptr, 0, SEEK_SET);

	res = malloc(file_size * sizeof(char));
	fread(res, sizeof(char), file_size, file_ptr);

	fclose(file_ptr);
	return res;
}