Add more exmaples and fix CI

examples/02_named_ports/main.cpp

@@ -1,3 +1,80 @@
+// Example 02 — Named Ports
+//
+// A three-stage text pipeline where port names carry semantic meaning:
+//
+//  [tokenise] --"words"--> [count_words] --"count"--> [report]
+//                                         --"words"--> [report]
+//
+// Named ports let the connect() call read like documentation:
+//   connect("tok", tok.output<"words">(), "cnt", cnt.input<"words">())
+// A typo in the name is a compile-time error, not a runtime surprise.
+
 #include <kpn/kpn.hpp>
-// TODO: implement example
-int main() { return 0; }
+#include <chrono>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <thread>
+#include <tuple>
+#include <vector>
+
+// ── Node functions ────────────────────────────────────────────────────────────
+
+static int sentence_index = 0;
+
+static std::vector<std::string> tokenise() {
+    static const char* sentences[] = {
+        "the quick brown fox jumps over the lazy dog",
+        "kahn process networks are a model of concurrent computation",
+        "each node runs in its own thread communicating via channels",
+        "named ports catch wiring mistakes at compile time",
+    };
+    std::istringstream ss(sentences[sentence_index++ % 4]);
+    std::vector<std::string> words;
+    std::string w;
+    while (ss >> w) words.push_back(w);
+    std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    return words;
+}
+
+// Returns (word_count, original_words) — two outputs via tuple
+static std::tuple<int, std::vector<std::string>>
+count_words(std::vector<std::string> words) {
+    return {static_cast<int>(words.size()), std::move(words)};
+}
+
+static void report(int count, std::vector<std::string> words) {
+    std::cout << "[" << count << " words] ";
+    for (auto& w : words) std::cout << w << ' ';
+    std::cout << '\n';
+}
+
+// ── main ──────────────────────────────────────────────────────────────────────
+
+int main() {
+    using namespace kpn;
+
+    // tokenise: no inputs, one named output "words"
+    auto tok = make_node<tokenise>(out<"words">{}, 4);
+
+    // count_words: named input "words", named outputs "count" and "words"
+    auto cnt = make_node<count_words>(in<"words">{}, out<"count", "words">{}, 4);
+
+    // report: two named inputs — note the function takes (int, vector<string>)
+    // so we need two separate input ports wired independently
+    // For a two-input sink we wire each output of cnt to a different input of report
+    auto snk = make_node<report>(in<"count", "words">{}, 4);
+
+    Network net;
+    net.add("tok", tok)
+       .add("cnt", cnt)
+       .add("snk", snk)
+       .connect("tok", tok.template output<"words">(), "cnt", cnt.template input<"words">())
+       .connect("cnt", cnt.template output<"count">(), "snk", snk.template input<"count">())
+       .connect("cnt", cnt.template output<"words">(), "snk", snk.template input<"words">())
+       .build();
+
+    net.start();
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    net.stop();
+}