Add history support, and fix parsing system.

include/internal/buffer/buffer.h

@@ -1,6 +1,5 @@
 #pragma once
 
-#include "clip.h"
+#include "./types/clip.h"
+#include "./types/generic.h"
 #include "decl.h"
-#include "generic.h"
-#include "pch.h"

include/internal/buffer/decl.h

@@ -10,7 +10,7 @@ namespace bed::internal::buffer {
 struct Buffer {
   enum struct Kind : uint8_t {
     Generic,
-    Null,
+    History,
     Clip,
     Cancel,
     Shell,
@@ -26,7 +26,7 @@ struct Buffer {
   std::string name;
 
   explicit Buffer(std::string name, Kind kind)
-      : kind(kind), state(Unmodified), name(name) {};
+      : kind(kind), state(Unmodified), name(std::move(name)) {};
   virtual ~Buffer() = default;
 
   virtual bool waste() = 0;

include/internal/buffer/types/clip.h

@@ -1,7 +1,6 @@
 #pragma once
 
-#include "decl.h"
-#include "pch.h"
+#include "../decl.h"
 
 namespace bed::internal::buffer {
 struct ClipBuffer : Buffer {

include/internal/buffer/types/generic.h

@@ -1,26 +1,41 @@
 #pragma once
 
-#include "decl.h"
-#include "pch.h"
+#include "../decl.h"
+#include "history.h"
+#include "shard.h"
 
 namespace bed::internal::buffer {
-struct GenericBuffer : Buffer {
-  vase::Shard *root;
+struct HistoryItem {
+  syntax::ParserSnapshot parse_state;
+  vase::Shard *text;
+  std::chrono::system_clock::time_point timestamp;
+  std::string summary;
+};
+
+struct GenericBuffer : ShardBuffer {
+  uint64_t base_version{0};
+  std::chrono::system_clock::time_point timestamp{
+    std::chrono::system_clock::now()
+  };
+  std::string action{"created"};
   std::filesystem::path save_path{};
-  std::string language{};
-  std::optional<syntax::Parser> parser{};
+  std::vector<HistoryItem> undo_stack;
+  std::vector<HistoryItem> redo_stack;
 
   GenericBuffer(std::string name)
-      : Buffer(name, Kind::Generic), root(nullptr) {};
+      : ShardBuffer(name, nullptr, nullptr, Kind::Generic) {}
   ~GenericBuffer();
 
+  void list_history(BEd &ctx);
+  HistoryBuffer *get_history(uint64_t version);
+  void snapshot(std::string action);
+  bool undo(BEd &ctx);
+  bool redo(BEd &ctx);
+  void prune(int = 0);
   bool waste() override;
-  uint64_t lines() override;
-  uint64_t bytes() override;
   void load(BEd &ctx, vase::Shard *text) override;
   void set_filename(std::filesystem::path path) override;
   std::filesystem::path filename() override;
-  vase::Shard *copy(uint64_t start_line, uint64_t end_line) override;
   void substitute(
     BEd &ctx, uint64_t start_line, uint64_t end_line,
     std::string &regex, std::string &replacement, std::string &options
@@ -29,12 +44,5 @@ struct GenericBuffer : Buffer {
   void remove(BEd &ctx, uint64_t start_line, uint64_t end_line) override;
   void append(BEd &ctx, vase::Shard *text, uint64_t line) override;
   void replace(BEd &ctx, vase::Shard *text, uint64_t start_line, uint64_t end_line) override;
-  void print(BEd &ctx, uint64_t start_line, uint64_t end_line) override;
-  void number_print(BEd &ctx, uint64_t start_line, uint64_t end_line) override;
-  void list_print(BEd &ctx, uint64_t start_line, uint64_t end_line) override;
-  uint64_t next_closing(uint64_t start) override;
-  uint64_t prev_closing(uint64_t start) override;
-  uint64_t find_next(std::string_view pattern, uint64_t start) override;
-  uint64_t find_prev(std::string_view pattern, uint64_t start) override;
 };
 } // namespace bed::internal::buffer

include/internal/buffer/types/history.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include "../decl.h"
+#include "shard.h"
+
+namespace bed::internal::buffer {
+struct HistoryBuffer : ShardBuffer {
+  HistoryBuffer(
+    std::string name, vase::Shard *root,
+    const syntax::ParserSnapshot &snapshot
+  ) : ShardBuffer(std::move(name), root, snapshot, Kind::History) {}
+
+  bool waste() override {
+    return true;
+  }
+  void load(BEd &, vase::Shard *) override {
+    throw ed_error("History buffers are read-only.");
+  }
+  void set_filename(std::filesystem::path) override {}
+  std::filesystem::path filename() override {
+    return {};
+  }
+  void substitute(BEd &, uint64_t, uint64_t, std::string &, std::string &, std::string &) override {
+    throw ed_error("History buffers are read-only.");
+  }
+  void join(BEd &, uint64_t, uint64_t) override {
+    throw ed_error("History buffers are read-only.");
+  }
+  void remove(BEd &, uint64_t, uint64_t) override {
+    throw ed_error("History buffers are read-only.");
+  }
+  void append(BEd &, vase::Shard *, uint64_t) override {
+    throw ed_error("History buffers are read-only.");
+  }
+  void replace(BEd &, vase::Shard *, uint64_t, uint64_t) override {
+    throw ed_error("History buffers are read-only.");
+  }
+};
+} // namespace bed::internal::buffer

include/internal/buffer/types/shard.h

@@ -0,0 +1,42 @@
+#pragma once
+
+#include "../decl.h"
+
+namespace bed::internal::buffer {
+struct ShardBuffer : Buffer {
+  vase::Shard *root;
+  syntax::ParserSnapshot parse{};
+
+  ShardBuffer(std::string name, vase::Shard *root, syntax::Language *language, Kind kind)
+      : Buffer(std::move(name), kind), root(root) {
+    vase::Shard::retain(root);
+    if (language)
+      parse = syntax::make_parser(root, lines(), language);
+  }
+  ShardBuffer(
+    std::string name,
+    vase::Shard *root,
+    const syntax::ParserSnapshot &snapshot,
+    Kind kind
+  ) : Buffer(std::move(name), kind),
+      root(root),
+      parse(syntax::retain(snapshot)) {
+    vase::Shard::retain(root);
+  }
+  ~ShardBuffer() {
+    vase::Shard::release(root);
+    syntax::release(parse);
+  }
+
+  uint64_t lines() override;
+  uint64_t bytes() override;
+  vase::Shard *copy(uint64_t start_line, uint64_t end_line) override;
+  void print(BEd &ctx, uint64_t start_line, uint64_t end_line) override;
+  void number_print(BEd &ctx, uint64_t start_line, uint64_t end_line) override;
+  void list_print(BEd &ctx, uint64_t start_line, uint64_t end_line) override;
+  uint64_t next_closing(uint64_t start) override;
+  uint64_t prev_closing(uint64_t start) override;
+  uint64_t find_next(std::string_view pattern, uint64_t start) override;
+  uint64_t find_prev(std::string_view pattern, uint64_t start) override;
+};
+} // namespace bed::internal::buffer