dict

Simple associative array single-header library

This is single header file library for associative arrays, either associating an int64_t value with another int64_t value or a string with another string. For the numeric associative array, the type and function prefix is dict. For the string associative array, the type and function prefix is sdict.

Usage:

Some users may find that defining a macro for the value function makes usage a bit more ergonomic. The library does not provide these due to namespace issues, user-programmers' individual preferences, and varied compiler support for the author's preferred macro names.

#include <stdio.h>
#include "dict.h"

int main(void) {
    dict *cpgmap = dictnew();
    sdict *uamap = sdictnew();
    #define cpgmap_(x) dictval(cpgmap, x)
    #define uamap_(x) sdictval(uamap, x)
    
    dictadd(cpgmap, 0, 1252);
    dictadd(cpgmap, 178, 1256);
    // ...
    sdictadd(uamap, "Win/FFX 83", "Mozilla/5.0 (Windows NT 10.0; "\
                    "Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0");
    sdictadd(uamap, "Mac/Safari 12", "Mozilla/5.0 (Macintosh; Intel"\
                    "Mac OS X 10_15_5 (Ergänzendes Update)) "\
                    "AppleWebKit/605.1.15 (KHTML, like Gecko) "\
                    "Version/12.1.1 Safari/605.1.15");
    // ...

    int64_t codepage = cpgmap_(178);
    printf("Charset 178 => code page %lld\n", codepage);
    
    char *activeua = uamap_("Win/FFX 83");
    printf("The full user agent for Win/FFX 83 is \'%s\'\n", activeua);

    free(activeua);
    dictdestroy(cpgmap);
    sdictdestroy(uamap);

    return 0;
}

The associative array is implemented as a sorted array of key-value structures. Value retrieval and value insertion are both implemented via binary search for the anticipated location of the given key. On insertion, if the key exists, the existing value is overwritten; if it does not, the elements after that point, if any, are shifted to the right and a new key-value pair is inserted. While this approach is O(log n) rather than O(1), the performance characteristics for most situations are acceptable.

torstenvl/dict

dict

Usage: