Task: Yahoo! search interface
C: 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
#include "wren.h"

struct MemoryStruct {
    char *memory;
    size_t size;
};



static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp) {
    size_t realsize = size * nmemb;
    struct MemoryStruct *mem = (struct MemoryStruct *)userp;
 
    char *ptr = realloc(mem->memory, mem->size + realsize + 1);
    if(!ptr) {
        
        printf("not enough memory (realloc returned NULL)\n");
        return 0;
    }

    mem->memory = ptr;
    memcpy(&(mem->memory[mem->size]), contents, realsize);
    mem->size += realsize;
    mem->memory[mem->size] = 0;
    return realsize;
}

void C_bufferAllocate(WrenVM* vm) {
    struct MemoryStruct *ms = (struct MemoryStruct *)wrenSetSlotNewForeign(vm, 0, 0, sizeof(struct MemoryStruct));
    ms->memory = malloc(1);
    ms->size = 0;
}

void C_bufferFinalize(void* data) {
    struct MemoryStruct *ms = (struct MemoryStruct *)data;
    free(ms->memory);
}

void C_curlAllocate(WrenVM* vm) {
    CURL** pcurl = (CURL**)wrenSetSlotNewForeign(vm, 0, 0, sizeof(CURL*));
    *pcurl = curl_easy_init();
}

void C_value(WrenVM* vm) {
    struct MemoryStruct *ms = (struct MemoryStruct *)wrenGetSlotForeign(vm, 0);
    wrenSetSlotString(vm, 0, ms->memory);
}

void C_easyPerform(WrenVM* vm) {
    CURL* curl = *(CURL**)wrenGetSlotForeign(vm, 0);
    curl_easy_perform(curl);
}

void C_easyCleanup(WrenVM* vm) {
    CURL* curl = *(CURL**)wrenGetSlotForeign(vm, 0);
    curl_easy_cleanup(curl);
}

void C_easySetOpt(WrenVM* vm) {
    CURL* curl = *(CURL**)wrenGetSlotForeign(vm, 0);
    CURLoption opt = (CURLoption)wrenGetSlotDouble(vm, 1);
    if (opt < 10000) {
        long lparam = (long)wrenGetSlotDouble(vm, 2);
        curl_easy_setopt(curl, opt, lparam);
    } else if (opt < 20000) {
        if (opt == CURLOPT_WRITEDATA) {
            struct MemoryStruct *ms = (struct MemoryStruct *)wrenGetSlotForeign(vm, 2);
            curl_easy_setopt(curl, opt, (void *)ms);
        } else if (opt == CURLOPT_URL) {
            const char *url = wrenGetSlotString(vm, 2);
            curl_easy_setopt(curl, opt, url);
        }
    } else if (opt < 30000) {
        if (opt == CURLOPT_WRITEFUNCTION) {
            curl_easy_setopt(curl, opt, &WriteMemoryCallback);
        }
    }
}

WrenForeignClassMethods bindForeignClass(WrenVM* vm, const char* module, const char* className) {
    WrenForeignClassMethods methods;
    methods.allocate = NULL;
    methods.finalize = NULL;
    if (strcmp(module, "main") == 0) {
        if (strcmp(className, "Buffer") == 0) {
            methods.allocate = C_bufferAllocate;
            methods.finalize = C_bufferFinalize;
        } else if (strcmp(className, "Curl") == 0) {
            methods.allocate = C_curlAllocate;
        }
    }
    return methods;
}

WrenForeignMethodFn bindForeignMethod(
    WrenVM* vm,
    const char* module,
    const char* className,
    bool isStatic,
    const char* signature) {
    if (strcmp(module, "main") == 0) {
        if (strcmp(className, "Buffer") == 0) {
            if (!isStatic && strcmp(signature, "value") == 0)           return C_value;
        } else if (strcmp(className, "Curl") == 0) {
            if (!isStatic && strcmp(signature, "easySetOpt(_,_)") == 0) return C_easySetOpt;
            if (!isStatic && strcmp(signature, "easyPerform()") == 0)   return C_easyPerform;
            if (!isStatic && strcmp(signature, "easyCleanup()") == 0)   return C_easyCleanup;
        }
    }
    return NULL;
}

static void writeFn(WrenVM* vm, const char* text) {
    printf("%s", text);
}

void errorFn(WrenVM* vm, WrenErrorType errorType, const char* module, const int line, const char* msg) {
    switch (errorType) {
        case WREN_ERROR_COMPILE:
            printf("[%s line %d] [Error] %s\n", module, line, msg);
            break;
        case WREN_ERROR_STACK_TRACE:
            printf("[%s line %d] in %s\n", module, line, msg);
            break;
        case WREN_ERROR_RUNTIME:
            printf("[Runtime Error] %s\n", msg);
            break;
    }
}

char *readFile(const char *fileName) {
    FILE *f = fopen(fileName, "r");
    fseek(f, 0, SEEK_END);
    long fsize = ftell(f);
    rewind(f);
    char *script = malloc(fsize + 1);
    fread(script, 1, fsize, f);
    fclose(f);
    script[fsize] = 0;
    return script;
}

static void loadModuleComplete(WrenVM* vm, const char* module, WrenLoadModuleResult result) {
    if( result.source) free((void*)result.source);
}

WrenLoadModuleResult loadModule(WrenVM* vm, const char* name) {
    WrenLoadModuleResult result = {0};
    if (strcmp(name, "random") != 0 && strcmp(name, "meta") != 0) {
        result.onComplete = loadModuleComplete;
        char fullName[strlen(name) + 6];
        strcpy(fullName, name);
        strcat(fullName, ".wren");
        result.source = readFile(fullName);
    }
    return result;
}

int main(int argc, char **argv) {
    WrenConfiguration config;
    wrenInitConfiguration(&config);
    config.writeFn = &writeFn;
    config.errorFn = &errorFn;
    config.bindForeignClassFn = &bindForeignClass;
    config.bindForeignMethodFn = &bindForeignMethod;
    config.loadModuleFn = &loadModule;
    WrenVM* vm = wrenNewVM(&config);
    const char* module = "main";
    const char* fileName = "yahoo_search_interface.wren";
    char *script = readFile(fileName);
    WrenInterpretResult result = wrenInterpret(vm, module, script);
    switch (result) {
        case WREN_RESULT_COMPILE_ERROR:
            printf("Compile Error!\n");
            break;
        case WREN_RESULT_RUNTIME_ERROR:
            printf("Runtime Error!\n");
            break;
        case WREN_RESULT_SUCCESS:
            break;
    }
    wrenFreeVM(vm);
    free(script);
    return 0;
}

C#: using System;
using System.Net;
using System.Text.RegularExpressions;
using System.Collections.Generic;

class YahooSearch {
    private string query;
    private string content;
    private int page;

    const string yahoo = "http:

    public YahooSearch(string query) : this(query, 0) { }

    public YahooSearch(string query, int page) {
        this.query = query;
        this.page = page;
        this.content = new WebClient()
            .DownloadString(
                string.Format(yahoo + "p={0}&b={1}", query, this.page * 10 + 1)
            );
    }

    public YahooResult[] Results {
        get {
            List<YahooResult> results = new List<YahooResult>();

            Func<string, string, string> substringBefore = (str, before) =>
            {
                int iHref = str.IndexOf(before);
                return iHref < 0 ? "" : str.Substring(0, iHref);
            };
            Func<string, string, string> substringAfter = (str, after) =>
            {
                int iHref = str.IndexOf(after);
                return iHref < 0 ? "" : str.Substring(iHref + after.Length);
            };
            Converter<string, string> getText = p => 
                Regex.Replace(p, "<[^>]*>", x => "");

            Regex rx = new Regex(@"
                <li>
                    <div \s class=""res"">
                        <div>
                            <h3>
                                <a \s (?'LinkAttributes'[^>]+)>
                                    (?'LinkText' .*?)
                                (?></a>)
                            </h3>
                        </div>
                        <div \s class=""abstr"">
                            (?'Abstract' .*?)
                        (?></div>)
                        .*?
                    (?></div>)
                </li>",
                RegexOptions.IgnorePatternWhitespace
                | RegexOptions.ExplicitCapture
            );
            foreach (Match e in rx.Matches(this.content)) {
                string rurl = getText(substringBefore(substringAfter(
                    e.Groups["LinkAttributes"].Value, @"href="""), @""""));
                string rtitle = getText(e.Groups["LinkText"].Value);
                string rcontent = getText(e.Groups["Abstract"].Value);
                
                results.Add(new YahooResult(rurl, rtitle, rcontent));
            }
            return results.ToArray();
        }
    }

    public YahooSearch NextPage() {
        return new YahooSearch(this.query, this.page + 1);
    }

    public YahooSearch GetPage(int page) {
        return new YahooSearch(this.query, page);
    }
}

class YahooResult {
    public string URL { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }

    public YahooResult(string url, string title, string content) {
        this.URL = url;
        this.Title = title;
        this.Content = content;
    }

    public override string ToString()
    {
        return string.Format("\nTitle: {0}\nLink:  {1}\nText:  {2}",
            Title, URL, Content);
    }
}



class Prog {
    static void Main() {
        foreach (int page in new[] { 0, 1 })
        {
            YahooSearch x = new YahooSearch("test", page);

            foreach (YahooResult result in x.Results)
            {
                Console.WriteLine(result);
            }
        }
    }
}