From 85c6bb3cd81b77d8e9cc58a39f7da35423adec50 Mon Sep 17 00:00:00 2001
From: Sy Brand <tartanllama@gmail.com>
Date: Mon, 9 Dec 2024 11:01:13 +0000
Subject: [PATCH] Change predicate names

---
 include/tl/functional/predicates.hpp | 22 ++++++++++------
 tests/predicates.cpp                 | 38 ++++++++++++++++------------
 2 files changed, 36 insertions(+), 24 deletions(-)

diff --git a/include/tl/functional/predicates.hpp b/include/tl/functional/predicates.hpp
index 3cf00be..b176bb6 100644
--- a/include/tl/functional/predicates.hpp
+++ b/include/tl/functional/predicates.hpp
@@ -2,32 +2,38 @@
 #define TL_RANGES_PREDICATES_HPP
 
 namespace tl {
-    inline constexpr auto equal_to = [](auto&& x) {
+    inline constexpr auto proj = [](auto&& f, auto&& p) {
+        return [f = std::forward<decltype(f)>(f), p = std::forward<decltype(p)>(p)](auto&&... args) {
+            return std::invoke(f, std::invoke(p, std::forward<decltype(args)>(args)...));
+        };
+    };
+
+    inline constexpr auto eq = [](auto&& x) {
         return [x = std::forward<decltype(x)>(x)](auto&& y) {
             return x == y;
         };
     };
-    inline constexpr auto not_equal_to = [](auto&& x) {
+    inline constexpr auto neq = [](auto&& x) {
         return [x = std::forward<decltype(x)>(x)](auto&& y) {
             return x != y;
         };
     };
-    inline constexpr auto less_than = [](auto&& x) {
+    inline constexpr auto lt = [](auto&& x) {
         return [x = std::forward<decltype(x)>(x)](auto&& y) {
             return y < x;
         };
     };
-    inline constexpr auto greater_than = [](auto&& x) {
+    inline constexpr auto gt = [](auto&& x) {
         return [x = std::forward<decltype(x)>(x)](auto&& y) {
             return y > x;
         };
     };
-    inline constexpr auto less_than_or_equal_to = [](auto&& x) {
+    inline constexpr auto lte = [](auto&& x) {
         return [x = std::forward<decltype(x)>(x)](auto&& y) {
             return y <= x;
         };
     };
-    inline constexpr auto greater_than_or_equal_to = [](auto&& x) {
+    inline constexpr auto gte = [](auto&& x) {
         return [x = std::forward<decltype(x)>(x)](auto&& y) {
             return y >= x;
         };
@@ -68,14 +74,14 @@ namespace tl {
     inline constexpr auto is_not_empty = [](auto&& x) {
         return !x.empty();
     };
-    inline constexpr auto conjunction = [](auto&&... predicates) {
+    inline constexpr auto both = [](auto&&... predicates) {
         return [predicates = std::make_tuple(std::forward<decltype(predicates)>(predicates)...)](auto&& x) {
             return std::apply([&x](auto&&... predicates) {
                 return (predicates(x) && ...);
             }, predicates);
         };
     };
-    inline constexpr auto disjunction = [](auto&&... predicates) {
+    inline constexpr auto either = [](auto&&... predicates) {
         return [predicates = std::make_tuple(std::forward<decltype(predicates)>(predicates)...)](auto&& x) {
             return std::apply([&x](auto&&... predicates) {
                 return (predicates(x) || ...);
diff --git a/tests/predicates.cpp b/tests/predicates.cpp
index 23296b8..f0e5fb7 100644
--- a/tests/predicates.cpp
+++ b/tests/predicates.cpp
@@ -1,41 +1,41 @@
 #include <catch2/catch.hpp>
 #include "tl/functional/predicates.hpp"
 
-TEST_CASE("equal_to") {
-    auto eq = tl::equal_to(5);
+TEST_CASE("eq") {
+    auto eq = tl::eq(5);
     REQUIRE(eq(5));
     REQUIRE_FALSE(eq(6));
 }
 
-TEST_CASE("not_equal_to") {
-    auto neq = tl::not_equal_to(5);
+TEST_CASE("neq") {
+    auto neq = tl::neq(5);
     REQUIRE_FALSE(neq(5));
     REQUIRE(neq(6));
 }
 
-TEST_CASE("less_than") {
-    auto lt = tl::less_than(5);
+TEST_CASE("lt") {
+    auto lt = tl::lt(5);
     REQUIRE(lt(4));
     REQUIRE_FALSE(lt(5));
     REQUIRE_FALSE(lt(6));
 }
 
-TEST_CASE("greater_than") {
-    auto gt = tl::greater_than(5);
+TEST_CASE("gt") {
+    auto gt = tl::gt(5);
     REQUIRE_FALSE(gt(4));
     REQUIRE_FALSE(gt(5));
     REQUIRE(gt(6));
 }
 
-TEST_CASE("less_than_or_equal_to") {
-    auto lte = tl::less_than_or_equal_to(5);
+TEST_CASE("lte") {
+    auto lte = tl::lte(5);
     REQUIRE(lte(4));
     REQUIRE(lte(5));
     REQUIRE_FALSE(lte(6));
 }
 
-TEST_CASE("greater_than_or_equal_to") {
-    auto gte = tl::greater_than_or_equal_to(5);
+TEST_CASE("gte") {
+    auto gte = tl::gte(5);
     REQUIRE_FALSE(gte(4));
     REQUIRE(gte(5));
     REQUIRE(gte(6));
@@ -121,16 +121,16 @@ TEST_CASE("is_not_null") {
     REQUIRE(inn(&inn));
 }
 
-TEST_CASE("conjunction") {
-    auto c = tl::conjunction(tl::is_even, tl::is_positive);
+TEST_CASE("both") {
+    auto c = tl::both(tl::is_even, tl::is_positive);
     REQUIRE_FALSE(c(0));
     REQUIRE_FALSE(c(1));
     REQUIRE(c(2));
     REQUIRE(c(4));
 }
 
-TEST_CASE("disjunction") {
-    auto d = tl::disjunction(tl::is_even, tl::is_positive);
+TEST_CASE("either") {
+    auto d = tl::either(tl::is_even, tl::is_positive);
     REQUIRE(d(0));
     REQUIRE(d(1));
     REQUIRE(d(2));
@@ -149,3 +149,9 @@ TEST_CASE("negation") {
     REQUIRE_FALSE(n(4));
 }
 
+TEST_CASE("proj") {
+    auto p = tl::proj([](int x) { return x + 1; }, [](int x) { return x + 2; });
+    REQUIRE(p(1) == 4);
+    REQUIRE(p(2) == 5);
+    REQUIRE(p(3) == 6);
+}
\ No newline at end of file