Move userspace to a templated StrFormat.

lib/glacier/CMakeLists.txt

@@ -1,6 +1,8 @@
 add_library(glacier STATIC
   string/string.cpp
+  string/string_builder.cpp
   string/string_view.cpp
+  string/str_format.cpp
   string/str_split.cpp
   )
 

lib/glacier/container/vector.h

@@ -57,6 +57,8 @@ class Vector {
   uint64_t size() const { return size_; }
   uint64_t capacity() const { return capacity_; }
 
+  const T* RawPtr() const { return data_; }
+
  private:
   T* data_;
   uint64_t size_;

lib/glacier/string/str_format.cpp

@@ -0,0 +1,73 @@
+#include "glacier/string/str_format.h"
+
+namespace glcr {
+
+namespace {
+
+void StrFormatNumber(StringBuilder& builder, uint64_t value, uint64_t base) {
+  const char* kHexCharacters = "0123456789ABCDEF";
+
+  if (value < base) {
+    builder.PushBack(kHexCharacters[value]);
+    return;
+  }
+
+  StrFormatNumber(builder, value / base, base);
+
+  builder.PushBack(kHexCharacters[value % base]);
+}
+
+}  // namespace
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint8_t value, StringView opts) {
+  StrFormatValue(builder, static_cast<uint64_t>(value), opts);
+}
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint16_t value, StringView opts) {
+  StrFormatValue(builder, static_cast<uint64_t>(value), opts);
+}
+
+template <>
+void StrFormatValue(StringBuilder& builder, int32_t value, StringView opts) {
+  StrFormatValue(builder, static_cast<uint64_t>(value), opts);
+}
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint32_t value, StringView opts) {
+  StrFormatValue(builder, static_cast<uint64_t>(value), opts);
+}
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint64_t value, StringView opts) {
+  if (opts.find('x') != opts.npos) {
+    builder.PushBack("0x");
+    StrFormatNumber(builder, value, 16);
+  } else {
+    StrFormatNumber(builder, value, 10);
+  }
+}
+
+template <>
+void StrFormatValue(StringBuilder& builder, ErrorCode value, StringView opts) {
+  StrFormatValue(builder, static_cast<uint64_t>(value), opts);
+}
+
+template <>
+void StrFormatValue(StringBuilder& builder, const char* value,
+                    StringView opts) {
+  StrFormatValue(builder, StringView(value), opts);
+}
+
+template <>
+void StrFormatValue(StringBuilder& builder, StringView value, StringView opts) {
+  StrFormatInternal(builder, value);
+}
+
+void StrFormatInternal(StringBuilder& builder, StringView format) {
+  // TODO: Consider throwing an error if there are unhandled format
+  builder.PushBack(format);
+}
+
+}  // namespace glcr

lib/glacier/string/str_format.h

@@ -0,0 +1,62 @@
+#pragma once
+
+#include "glacier/memory/move.h"
+#include "glacier/status/error.h"
+#include "glacier/string/string_builder.h"
+#include "glacier/string/string_view.h"
+
+namespace glcr {
+
+template <typename T>
+void StrFormatValue(StringBuilder& builder, T value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint8_t value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint16_t value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, int32_t value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint32_t value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, uint64_t value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, ErrorCode value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, const char* value, StringView opts);
+
+template <>
+void StrFormatValue(StringBuilder& builder, StringView value, StringView opts);
+
+void StrFormatInternal(StringBuilder& builder, StringView format);
+
+template <typename T, typename... Args>
+void StrFormatInternal(StringBuilder& builder, StringView format, T value,
+                       Args... args) {
+  uint64_t posl = format.find('{');
+  uint64_t posr = format.find('}', posl);
+  if (posl == format.npos || posr == format.npos) {
+    // TODO: Consider throwing an error since we still have values to consume.
+    return StrFormatInternal(builder, format);
+  }
+
+  builder.PushBack(format.substr(0, posl));
+  StrFormatValue(builder, value, format.substr(posl + 1, posr - posl - 1));
+  StrFormatInternal(builder, format.substr(posr + 1, format.size() - posr - 1),
+                    args...);
+}
+
+template <typename... Args>
+StringBuilder StrFormat(StringView format, Args... args) {
+  StringBuilder builder;
+  StrFormatInternal(builder, format, args...);
+  return glcr::Move(builder);
+}
+
+}  // namespace glcr

lib/glacier/string/string_builder.cpp

@@ -0,0 +1,24 @@
+#include "glacier/string/string_builder.h"
+
+namespace glcr {
+
+void StringBuilder::PushBack(const StringView& str) {
+  if (capacity() < size() + str.size()) {
+    uint64_t new_capacity = capacity() == 0 ? 1 : capacity() * 2;
+    while (new_capacity < size() + str.size()) {
+      new_capacity *= 2;
+    }
+    Resize(new_capacity);
+  }
+  for (uint64_t i = 0; i < str.size(); i++) {
+    Vector<char>::PushBack(str[i]);
+  }
+}
+
+String StringBuilder::ToString() const { return String(RawPtr(), size()); }
+
+StringBuilder::operator StringView() const {
+  return StringView(RawPtr(), size());
+}
+
+}  // namespace glcr

lib/glacier/string/string_builder.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "glacier/container/vector.h"
+#include "glacier/string/string.h"
+#include "glacier/string/string_view.h"
+
+namespace glcr {
+
+class StringBuilder : public Vector<char> {
+ public:
+  StringBuilder() : Vector<char>() {}
+  StringBuilder(const StringBuilder&) = delete;
+  StringBuilder(StringBuilder&& str) : Vector<char>(Move(str)) {}
+
+  void PushBack(const StringView& str);
+  using Vector<char>::PushBack;
+
+  String ToString() const;
+
+  // Note that this could become invalidated
+  // at any time if more characters are pushed
+  // onto the builder.
+  operator StringView() const;
+};
+
+}  // namespace glcr

lib/glacier/string/string_view.cpp

@@ -25,6 +25,7 @@ uint64_t StringView::size() const { return size_; }
 bool StringView::empty() const { return size_ == 0; }
 
 char StringView::at(uint64_t pos) const { return value_[pos]; }
+char StringView::operator[](uint64_t pos) const { return at(pos); };
 
 uint64_t StringView::find(char c, uint64_t pos) const {
   for (uint64_t i = pos; i < size_; i++) {

lib/glacier/string/string_view.h

@@ -19,6 +19,7 @@ class StringView {
   bool empty() const;
 
   char at(uint64_t pos) const;
+  char operator[](uint64_t pos) const;
 
   uint64_t find(char c, uint64_t pos = 0) const;