[Glacier] Add the ability to remove a character from a StringBuilder.

lib/glacier/container/vector.h

@@ -45,6 +45,8 @@ class Vector {
   template <typename... Args>
   void EmplaceBack(Args&&... args);
 
+  T&& PopBack();
+
  private:
   T* data_;
   uint64_t size_;
@@ -119,6 +121,12 @@ void Vector<T>::EmplaceBack(Args&&... args) {
   data_[size_++] = T(args...);
 }
 
+template <typename T>
+T&& Vector<T>::PopBack() {
+  size_--;
+  return glcr::Move(data_[size_]);
+}
+
 template <typename T>
 void Vector<T>::Expand() {
   uint64_t new_capacity = capacity_ == 0 ? 1 : capacity_ * 2;

lib/glacier/string/string_builder.cpp

@@ -19,6 +19,14 @@ void VariableStringBuilder::PushBack(const StringView& str) {
 
 void VariableStringBuilder::PushBack(const char str) { data_.PushBack(str); }
 
+void VariableStringBuilder::DeleteLast() {
+  if (data_.size() > 0) {
+    data_.PopBack();
+  }
+}
+
+void VariableStringBuilder::Reset() { data_ = glcr::Vector<char>(); }
+
 String VariableStringBuilder::ToString() const {
   return String(data_.RawPtr(), size());
 }
@@ -50,4 +58,12 @@ FixedStringBuilder::operator StringView() const {
   return StringView(buffer_, size_);
 }
 
+void FixedStringBuilder::DeleteLast() {
+  if (size_ > 0) {
+    size_--;
+  }
+}
+
+void FixedStringBuilder::Reset() { size_ = 0; }
+
 }  // namespace glcr

lib/glacier/string/string_builder.h

@@ -12,6 +12,9 @@ class StringBuilder {
   virtual void PushBack(const StringView& str) = 0;
   virtual void PushBack(const char str) = 0;
 
+  virtual void DeleteLast() = 0;
+  virtual void Reset() = 0;
+
   virtual String ToString() const = 0;
 
   virtual operator StringView() const = 0;
@@ -30,6 +33,9 @@ class VariableStringBuilder : public StringBuilder {
   virtual void PushBack(const StringView& str) override;
   virtual void PushBack(const char str) override;
 
+  virtual void DeleteLast() override;
+  virtual void Reset() override;
+
   virtual String ToString() const override;
 
   // Note that this could become invalidated
@@ -56,6 +62,9 @@ class FixedStringBuilder : public StringBuilder {
   virtual void PushBack(const StringView& str) override;
   virtual void PushBack(const char str) override;
 
+  virtual void DeleteLast() override;
+  virtual void Reset() override;
+
   virtual String ToString() const override;
 
   virtual operator StringView() const override;