From 255fa256b106506e0c951f704314c5c633217468 Mon Sep 17 00:00:00 2001
From: Dominick Allen <djallen@librehumanitas.org>
Date: Wed, 25 Sep 2024 11:25:25 -0500
Subject: Further expansion of string api.

---
 include/fud_result.hpp |  2 +-
 include/fud_string.hpp |  9 ++++++++-
 include/libfud.hpp     | 36 +++++++++++++++---------------------
 source/fud_string.cpp  | 14 ++++++++++++++
 source/libfud.cpp      | 21 ++++++++++++++++++++-
 5 files changed, 58 insertions(+), 24 deletions(-)

diff --git a/include/fud_result.hpp b/include/fud_result.hpp
index 9c69800..e4e36cf 100644
--- a/include/fud_result.hpp
+++ b/include/fud_result.hpp
@@ -24,7 +24,7 @@
 namespace fud {
 
 template<typename T, typename E>
-class Result {
+class [[nodiscard]] Result {
 public:
     using ResultType = Result<T, E>;
     static ResultType okay(const T& okay)
diff --git a/include/fud_string.hpp b/include/fud_string.hpp
index 5229f26..f7e4813 100644
--- a/include/fud_string.hpp
+++ b/include/fud_string.hpp
@@ -47,6 +47,11 @@ class String {
         return m_length;
     }
 
+    [[nodiscard]] constexpr bool empty() const
+    {
+        return m_length == 0;
+    }
+
     [[nodiscard]] constexpr size_t size() const
     {
         return m_length + 1;
@@ -89,6 +94,8 @@ class String {
 
     [[nodiscard]] FudStatus nullTerminate();
 
+    [[nodiscard]] std::optional<utf8> back();
+
     [[nodiscard]] constexpr size_t remainingLength() const
     {
         if (m_length >= m_capacity) {
@@ -136,7 +143,7 @@ class StringView {
     }
 
     StringView(size_t strLen, const char* strData) :
-        m_length(strLen),                                   // line break
+        m_length(strLen),                              // line break
         m_data{reinterpret_cast<const utf8*>(strData)} // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
     {
     }
diff --git a/include/libfud.hpp b/include/libfud.hpp
index ceb1b20..a0b2909 100644
--- a/include/libfud.hpp
+++ b/include/libfud.hpp
@@ -18,31 +18,25 @@
 #ifndef LIBFUD_HPP
 #define LIBFUD_HPP
 
-#include "fud_status.hpp" // IWYU pragma: export
+#include "fud_status.hpp"
+#include "fud_result.hpp"
+#include "fud_string.hpp"
 
-#include "fud_result.hpp" // IWYU pragma: export
-
-#include "fud_memory.hpp" // IWYU pragma: export
-
-#include "fud_assert.hpp" // IWYU pragma: export
-
-#include "fud_array.hpp" // IWYU pragma: export
-
-#include "fud_c_file.hpp" // IWYU pragma: export
-
-#include "fud_fud_type_traits.hpp" // IWYU pragma: export
-
-#include "fud_string.hpp" // IWYU pragma: export
-
-#include "fud_unique_array.hpp" // IWYU pragma: export
+namespace fud {
 
-#include "fud_utf8.hpp" // IWYU pragma: export
+Result<String, FudStatus> getEnv(const char* name);
 
-#include "fud_utf8_iterator.hpp" // IWYU pragma: export
+template<typename T>
+concept CStringRepr = requires(T a)
+{
+    { a.c_str() } -> std::convertible_to<const char*>;
+};
 
-namespace fud {
-
-void fud();
+template <CStringRepr T>
+Result<String, FudStatus> getEnv(const T& name)
+{
+    return getEnv(name.c_str());
+}
 
 }
 
diff --git a/source/fud_string.cpp b/source/fud_string.cpp
index 27496ff..57bf1e0 100644
--- a/source/fud_string.cpp
+++ b/source/fud_string.cpp
@@ -157,6 +157,20 @@ FudStatus String::nullTerminate()
     return FudStatus::StringInvalid;
 }
 
+[[nodiscard]] std::optional<utf8> String::back()
+{
+    if (!valid()) {
+        return std::nullopt;
+    }
+
+    utf8 backChar = data()[m_length - 1];
+    if (Ascii::valid(backChar)) {
+        return backChar;
+    }
+
+    return std::nullopt;
+}
+
 std::optional<utf8> String::pop()
 {
     if (m_length < 1) {
diff --git a/source/libfud.cpp b/source/libfud.cpp
index 834082e..e1dad1d 100644
--- a/source/libfud.cpp
+++ b/source/libfud.cpp
@@ -17,10 +17,29 @@
 
 #include "libfud.hpp"
 
+#include <cstdlib>
+
 namespace fud {
 
-void fud()
+Result<String, FudStatus> getEnv(const char* name)
 {
+    using RetType = Result<String, FudStatus>;
+
+    if (name == nullptr) {
+        return RetType::error(FudStatus::NullPointer);
+    }
+
+    const char* resultString = getenv(name);
+    if (resultString == nullptr) {
+        return RetType::error(FudStatus::NotFound);
+    }
+
+    String envVar{resultString};
+    if (!envVar.valid()) {
+        return RetType::error(FudStatus::Failure);
+    }
+
+    return RetType::okay(std::move(envVar));
 }
 
 } // namespace fud
-- 
cgit v1.2.3