From 982fed7f0e1e52479151c3e43d78d6cf35684250 Mon Sep 17 00:00:00 2001
From: Gryfenfer97
Date: Sat, 1 Feb 2025 19:43:32 +0100
Subject: Add C++ language

---
 languages/c/c++/README.md       | 13 ++++++++
 languages/c/c++/lambda-core.cpp | 67 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 languages/c/c++/README.md
 create mode 100644 languages/c/c++/lambda-core.cpp

(limited to 'languages/c/c++')

diff --git a/languages/c/c++/README.md b/languages/c/c++/README.md
new file mode 100644
index 0000000..41b7129
--- /dev/null
+++ b/languages/c/c++/README.md
@@ -0,0 +1,13 @@
+# C++ Lambda Core
+
+## Requirements
+
+- GCC 14 or above
+
+## Compile and run
+
+```sh
+g++ lambda-core.cpp -std=c++23 -o app
+./app
+```
+
diff --git a/languages/c/c++/lambda-core.cpp b/languages/c/c++/lambda-core.cpp
new file mode 100644
index 0000000..3c1ae20
--- /dev/null
+++ b/languages/c/c++/lambda-core.cpp
@@ -0,0 +1,67 @@
+#include <print>
+
+namespace logic {
+constexpr auto _true = [](const auto &x) {
+  return [&x](const auto &) { return x; };
+};
+
+constexpr auto _false = [](const auto &) {
+  return [](const auto &y) { return y; };
+};
+
+constexpr auto _not = [](const auto &x) { return x(_false)(_true); };
+
+constexpr auto _and = [](const auto &x) {
+  return [&x](const auto &y) { return x(y)(_false); };
+};
+
+constexpr auto _or = [](const auto &x) {
+  return [&x](const auto &y) { return x(_true)(y); };
+};
+
+namespace test {
+constexpr bool convert(const auto &x) { return x(true)(false); }
+
+void print(const auto &x) { std::println("{}", convert(x)); }
+} // namespace test
+} // namespace logic
+
+namespace church {
+constexpr auto zero = [](const auto &) {
+  return [](const auto &x) { return x; };
+};
+
+constexpr auto succ = [](const auto &n) {
+  return [&n](const auto &f) {
+    return [&n, &f](const auto &x) { return f(n(f)(x)); };
+  };
+};
+
+constexpr auto one = succ(zero);
+
+namespace test {
+constexpr unsigned int convert(const auto &n) {
+  return n([](const auto &x) { return x + 1; })(0);
+}
+
+void print(const auto &n) { std::println("{}", convert(n)); }
+} // namespace test
+} // namespace church
+
+int main() {
+  using namespace logic;
+  using namespace church;
+
+  static_assert(logic::test::convert(_true) == true);
+  static_assert(logic::test::convert(_false) == false);
+  static_assert(logic::test::convert(_and(_true)(_true)) == true);
+  static_assert(logic::test::convert(_and(_true)(_false)) == false);
+  static_assert(logic::test::convert(_or(_true)(_true)) == true);
+  static_assert(logic::test::convert(_or(_true)(_false)) == true);
+  logic::test::print(_true);
+
+  static_assert(church::test::convert(zero) == 0);
+  static_assert(church::test::convert(succ(zero)) == 1);
+  // static_assert(church::test::convert(pred(succ(one))) == 1);
+  church::test::print(one);
+}
-- 
cgit v1.2.3


From 3d7b2ecc046b1c8c57766eef325590fd66cb5032 Mon Sep 17 00:00:00 2001
From: Gryfenfer97
Date: Sat, 1 Feb 2025 19:55:25 +0100
Subject: add pred function

---
 languages/c/c++/lambda-core.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

(limited to 'languages/c/c++')

diff --git a/languages/c/c++/lambda-core.cpp b/languages/c/c++/lambda-core.cpp
index 3c1ae20..a6ce614 100644
--- a/languages/c/c++/lambda-core.cpp
+++ b/languages/c/c++/lambda-core.cpp
@@ -39,6 +39,16 @@ constexpr auto succ = [](const auto &n) {
 
 constexpr auto one = succ(zero);
 
+constexpr auto pred(const auto &n) {
+  return [&n](const auto &f) {
+    return [&n, &f](auto x) {
+      return n([&f](const auto &g) {
+        return [&f, g](const auto &h) { return h(g(f)); };
+      })([x](const auto &u) { return x; })([](const auto &a) { return a; });
+    };
+  };
+}
+
 namespace test {
 constexpr unsigned int convert(const auto &n) {
   return n([](const auto &x) { return x + 1; })(0);
@@ -62,6 +72,6 @@ int main() {
 
   static_assert(church::test::convert(zero) == 0);
   static_assert(church::test::convert(succ(zero)) == 1);
-  // static_assert(church::test::convert(pred(succ(one))) == 1);
+  static_assert(church::test::convert(pred(succ(one))) == 1);
   church::test::print(one);
 }
-- 
cgit v1.2.3


From ac45c34c705dc2114d1155b66545d2b3a7ed5613 Mon Sep 17 00:00:00 2001
From: Gryfenfer97
Date: Sat, 1 Feb 2025 19:59:12 +0100
Subject: transform pred in a lambda function

---
 languages/c/c++/lambda-core.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'languages/c/c++')

diff --git a/languages/c/c++/lambda-core.cpp b/languages/c/c++/lambda-core.cpp
index a6ce614..c9e73b9 100644
--- a/languages/c/c++/lambda-core.cpp
+++ b/languages/c/c++/lambda-core.cpp
@@ -39,7 +39,7 @@ constexpr auto succ = [](const auto &n) {
 
 constexpr auto one = succ(zero);
 
-constexpr auto pred(const auto &n) {
+constexpr auto pred = [](const auto &n) {
   return [&n](const auto &f) {
     return [&n, &f](auto x) {
       return n([&f](const auto &g) {
@@ -47,7 +47,7 @@ constexpr auto pred(const auto &n) {
       })([x](const auto &u) { return x; })([](const auto &a) { return a; });
     };
   };
-}
+};
 
 namespace test {
 constexpr unsigned int convert(const auto &n) {
-- 
cgit v1.2.3