1 files changed, 156 insertions, 0 deletions
diff --git a/asl/strings/string_builder.hpp b/asl/strings/string_builder.hpp
new file mode 100644
index 0000000..d30f1d5
--- /dev/null
+++ b/asl/strings/string_builder.hpp
@@ -0,0 +1,156 @@
+#pragma once
+
+#include "asl/containers/buffer.hpp"
+#include "asl/strings/string.hpp"
+#include "asl/strings/string_view.hpp"
+#include "asl/formatting/format.hpp"
+#include "asl/io/writer.hpp"
+
+namespace asl
+{
+
+template<allocator Allocator = DefaultAllocator>
+class StringBuilder
+{
+    buffer<char, Allocator> m_buffer;
+
+public:
+    constexpr StringBuilder() requires default_constructible<Allocator> = default;
+    explicit constexpr StringBuilder(Allocator allocator) : m_buffer{ASL_MOVE(allocator)} {}
+
+    constexpr ~StringBuilder() = default;
+
+    constexpr StringBuilder(const StringBuilder&) requires copy_constructible<Allocator> = default;
+    constexpr StringBuilder(StringBuilder&&) = default;
+
+    constexpr StringBuilder& operator=(const StringBuilder&) requires copy_assignable<Allocator> = default;
+    constexpr StringBuilder& operator=(StringBuilder&&) = default;
+
+    constexpr string_view as_string_view() const
+    {
+        auto span = m_buffer.as_span();
+        return string_view{span.data(), span.size()};
+    }
+
+    void reset()
+    {
+        m_buffer.clear();
+    }
+
+    // @Todo(C++23) Deducing this
+
+    StringBuilder& push(string_view sv) &
+    {
+        isize_t old_size = m_buffer.size();
+        m_buffer.resize_zero(old_size + sv.size());
+        asl::memcpy(m_buffer.data() + old_size, sv.data(), sv.size());
+        return *this;
+    }
+
+    StringBuilder&& push(string_view sv) &&
+    {
+        isize_t old_size = m_buffer.size();
+        m_buffer.resize_zero(old_size + sv.size());
+        asl::memcpy(m_buffer.data() + old_size, sv.data(), sv.size());
+        return ASL_MOVE(*this);
+    }
+
+    StringBuilder& push(char c) &
+    {
+        m_buffer.push(c);
+        return *this;
+    }
+
+    StringBuilder&& push(char c) &&
+    {
+        m_buffer.push(c);
+        return ASL_MOVE(*this);
+    }
+
+    string<Allocator> finish() &&
+    {
+        return string<Allocator>{ASL_MOVE(m_buffer)};
+    }
+
+    template<allocator StringAllocator = Allocator>
+    string<StringAllocator> as_string()
+        requires default_constructible<StringAllocator>
+    {
+        return string<StringAllocator>{as_string_view()};
+    }
+
+    template<allocator StringAllocator = Allocator>
+    string<StringAllocator> as_string(Allocator allocator)
+    {
+        return string<StringAllocator>{as_string_view(), ASL_MOVE(allocator)};
+    }
+};
+
+StringBuilder() -> StringBuilder<>;
+
+template<typename Allocator = DefaultAllocator>
+class StringWriter : public asl::Writer
+{
+    StringBuilder<Allocator> m_builder;
+
+public:
+    constexpr StringWriter() requires default_constructible<Allocator> = default;
+    explicit constexpr StringWriter(Allocator allocator) : m_builder{ASL_MOVE(allocator)} {}
+
+    constexpr ~StringWriter() override = default;
+
+    constexpr StringWriter(const StringWriter&) requires copy_constructible<Allocator> = default;
+    constexpr StringWriter(StringWriter&&) = default;
+
+    constexpr StringWriter& operator=(const StringWriter&) requires copy_assignable<Allocator> = default;
+    constexpr StringWriter& operator=(StringWriter&&) = default;
+
+    void write(span<const byte> str) override
+    {
+        m_builder.push(string_view{reinterpret_cast<const char*>(str.data()), str.size()});
+    }
+
+    constexpr string_view as_string_view() const
+    {
+        return m_builder.as_string_view();
+    }
+
+    string<Allocator> finish() &&
+    {
+        return ASL_MOVE(m_builder).finish();
+    }
+
+    template<allocator StringAllocator = Allocator>
+    string<StringAllocator> as_string()
+        requires default_constructible<StringAllocator>
+    {
+        return m_builder.as_string();
+    }
+
+    template<allocator StringAllocator = Allocator>
+    string<StringAllocator> as_string(Allocator allocator)
+    {
+        return m_builder.as_string(ASL_MOVE(allocator));
+    }
+};
+
+StringWriter() -> StringWriter<>;
+
+template<allocator Allocator = DefaultAllocator, formattable... Args>
+string<Allocator> format_to_string(string_view fmt, const Args&... args)
+    requires default_constructible<Allocator>
+{
+    StringWriter writer{};
+    format(&writer, fmt, args...);
+    return ASL_MOVE(writer).finish();
+}
+
+template<allocator Allocator = DefaultAllocator, formattable... Args>
+string<Allocator> format_to_string(Allocator allocator, string_view fmt, const Args&... args)
+{
+    StringWriter writer{ASL_MOVE(allocator)};
+    format(&writer, fmt, args...);
+    return ASL_MOVE(writer).finish();
+}
+
+} // namespace asl