Major updates:

- A lotta cleanup
- BEd command parser rewrite
- Vase class removed
- Proper IO system.
- A lot more.

include/bed.h

@@ -2,35 +2,25 @@
 
 #include "definitions.h"
 #include "internal/buffer/buffer.h"
-#include "internal/commands/commands.h"
-#include "internal/commands/suffixes.h"
+#include "internal/functions/functions.h"
+#include "internal/functions/suffixes.h"
+#include "internal/io/command.h"
 #include "internal/io/io.h"
 #include "internal/marks/marks.h"
 #include "internal/theme/theme.h"
+#include "internal/ui/autocomp.h"
 #include "pch.h"
 
 namespace bed {
-struct Suggestion {
-  enum : uint8_t {
-    Command,
-    Address,
-    Suffix,
-    History,
-    Regex
-  } type;
-  std::string_view name;
-  std::string_view desc;
-  std::string completion;
-};
-
 struct BEd {
-  internal::trie::Trie<internal::commands::Command> commands;
-  internal::commands::Command no_op;
-  internal::commands::Command eof_op;
-  std::array<std::optional<internal::commands::Suffix>, 26> suffixes;
+  internal::trie::Trie<internal::functions::Function> functions;
+  internal::functions::Function no_op;
+  internal::functions::Function eof_op;
+  std::array<std::optional<internal::functions::Suffix>, 26> suffixes;
   internal::theme::Theme theme;
   std::unordered_map<std::string, internal::syntax::Language> languages;
   internal::io::IO &io;
+  internal::vase::AppendStorage append{"/tmp"};
 
   bool help_mode = false;
   std::string last_help = "";
@@ -38,12 +28,21 @@ struct BEd {
   std::function<std::string(BEd &)> prompt = nullptr;
   bool suppress_mode = false;
   std::string last_regex = "";
+  std::string last_symbol = "";
+  std::string last_replacement = "";
 
   std::unordered_map<std::string, internal::buffer::Buffer *> buffers;
-  internal::buffer::Buffer *active;
+
+  internal::buffer::Range prev;
+  internal::marks::MarksEngine marks;
 
   BEd(std::vector<std::string> args, internal::io::IO &io);
   ~BEd();
+
+  internal::buffer::Buffer &buffer(const std::string &);
+  internal::buffer::Line &current();
+  void mark(char, internal::buffer::Line);
+
   void handle(std::string_view cmd, bool eof);
   void run();
   void suffix_handle(char s);

include/definitions.h

@@ -4,6 +4,8 @@
 #include "pch.h"
 
 namespace bed {
+struct BEd;
+
 struct fatal_error : std::runtime_error {
   uint8_t code;
   fatal_error(std::string msg, uint8_t code)
@@ -26,6 +28,4 @@ struct Highlight {
   uint32_t bg;
   uint8_t flags;
 };
-
-struct BEd;
 } // namespace bed

include/internal/address/address.h

@@ -1,108 +0,0 @@
-#pragma once
-
-#include "definitions.h"
-#include "internal/generic.h"
-#include "pch.h"
-
-namespace bed::internal::address {
-struct address_error : ed_error {
-  address_error(const char *msg) : ed_error(msg) {}
-};
-
-struct Address {
-  // % refers to range of whatever was resulted from the previous modification.
-  // it expands in theory to a Num,Num and so can be followed by chaining more adresses the ed way.
-  // this is handled and resolved by the handle function,
-  // the constuctor and resolve etc. are also only called in the handle function,
-  //
-  // in case of any issue an instance of address_error(const char *) is thrown.
-
-  struct Result {
-    std::array<uint64_t, 2> data{};
-    uint8_t size{0};
-    std::span<const uint64_t> span(uint8_t max = UINT8_MAX) const {
-      return {data.data(), std::min(size, max)};
-    }
-  };
-
-  struct None {};
-
-  // Posix ed types of addressing.
-  struct Current {}; // .
-
-  struct Last {}; // $
-
-  struct Number { // n
-    uint64_t i;
-  };
-
-  struct Mark { // 'm
-    char m;
-  };
-
-  struct Regex { // /re/ or ?re?
-    internal::Direction dir;
-    std::string re;
-  };
-
-  // extended types
-  struct Diagnostic { // #n# for diagnostic number n. (From lsp.)
-    uint16_t n;
-  };
-
-  struct DiagnosticNext { // ^ or % for previous/next diagnostic
-    internal::Direction dir;
-  };
-
-  struct SymbolDefinition { // <sym> goto symbol definition. (From lsp or using internal language parsers)
-    std::string sym;
-  };
-
-  struct SymbolReference { // <sym:n> goto nth symbol reference
-    uint16_t n;
-    std::string sym;
-  };
-
-  struct SymbolReferenceNext { // >sym> or <sym<
-    internal::Direction dir;   // goto next or previous symbol reference
-    std::string sym;
-  };
-
-  struct Block { // [ or ] goto start/end of containing block.
-    internal::Direction dir;
-  };
-
-  struct Scripted {   // (function_name:arguments)
-    std::string func; // Calls ruby mapping with name giving the argument as string.
-    std::string arg;  // resolves to line number returned by function (or throws error).
-                      // The mruby runtime also has the full context of the file and extentions etc.
-  };
-
-  std::variant<
-    std::monostate,
-    None,
-    Current,
-    Last,
-    Number,
-    Mark,
-    Regex,
-    Diagnostic,
-    DiagnosticNext,
-    SymbolDefinition,
-    SymbolReference,
-    SymbolReferenceNext,
-    Block,
-    Scripted>
-    base{};
-
-  // they can then be followed by any number of +n or -n etc accumulating in.
-  int64_t offset = 0;
-
-  Address(std::string &cmd, uint64_t &i);
-  Address() = default;
-
-  uint64_t resolve(BEd &ctx);
-
-  static Result handle(BEd &ctx, std::string &cmd, uint64_t &i);
-};
-} // namespace bed::internal::address

include/internal/buffer/buffer.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "definitions.h"
-#include "internal/marks/marks.h"
 #include "internal/syntax/parser.h"
 #include "internal/syntax/ruby/parser.h"
 #include "internal/theme/theme.h"
@@ -9,36 +8,67 @@
 
 namespace bed::internal::buffer {
 struct Buffer {
-  vase::Vase vase;
-  marks::MarksEngine marks;
-  std::string language;
-  std::optional<syntax::Parser> parser;
-  uint64_t line = 0;
-  bool modified;
+  enum {
+    Unmodified,
+    Modified,
+    Warned
+  } state;
   std::filesystem::path save_path = "";
 
-  struct {
-    uint64_t start{0};
-    uint64_t end{0};
-    std::span<const uint64_t> values() const {
-      return {&start, 2};
-    }
-  } prev_range;
+  vase::Shard *root;
 
-  Buffer();
-  Buffer(std::string command);
-  Buffer(std::filesystem::path path);
+  std::string name;
+  std::string language;
+  std::optional<syntax::Parser> parser;
 
-  ~Buffer() = default;
+  explicit Buffer(std::string name);
+  ~Buffer();
 
-  void load(std::string command);
-  void load(std::filesystem::path path);
-  void jump(uint64_t n_line);
-  void join(uint64_t start_line, uint64_t end_line);
-  void remove(uint64_t start_line, uint64_t end_line);
-  void append(std::string text, uint64_t line);
+  uint64_t lines();
+  vase::Shard *copy(uint64_t start_line, uint64_t end_line);
+  void substitute(
+    BEd &ctx, uint64_t start_line, uint64_t end_line,
+    std::string &regex, std::string &replacement, std::string &options
+  );
+  void join(BEd &ctx, uint64_t start_line, uint64_t end_line);
+  void remove(BEd &ctx, uint64_t start_line, uint64_t end_line);
+  void append(BEd &ctx, vase::Shard *text, uint64_t line);
   void print(BEd &ctx, uint64_t start_line, uint64_t end_line);
   void number_print(BEd &ctx, uint64_t start_line, uint64_t end_line);
   std::string list_string(std::string_view s);
 };
+
+struct Line {
+  std::string buffername;
+  uint64_t number;
+};
+
+struct Range {
+  std::string buffername;
+  uint64_t start;
+  uint64_t end;
+
+  explicit Range(const Line &a, const Line &b) {
+    if (a.buffername != b.buffername)
+      throw ed_error("Invalid range.");
+    if (a.number > b.number)
+      throw ed_error("Invalid range.");
+    buffername = a.buffername;
+    start = a.number;
+    end = b.number;
+  };
+
+  explicit Range(std::string buffername, uint64_t start, uint64_t end)
+      : buffername(buffername), start(start), end(end) {
+    if (start > end)
+      throw ed_error("Invalid range.");
+  };
+
+  explicit Range() : buffername("default"), start(0), end(0) {};
+};
+
+using Address = std::variant<
+  std::string,
+  buffer::Range,
+  buffer::Line>;
 } // namespace bed::internal::buffer

include/internal/commands/commands.h

@@ -1,30 +0,0 @@
-#pragma once
-
-#include "definitions.h"
-#include "internal/trie/trie.h"
-#include "pch.h"
-
-namespace bed::internal::commands {
-struct Command {
-  enum struct AddressMode : uint8_t {
-    None,
-    Single,
-    Range
-  } address_mode;
-
-  enum struct SuffixKind : uint8_t {
-    None,
-    Suffix,
-    Argument,
-    Continuation
-  } suffix;
-
-  std::string desc;
-
-  bool accept_zero;
-
-  void (*handle)(BEd &, std::span<const uint64_t>, std::string_view);
-
-  static void register_posix(BEd &ctx);
-};
-} // namespace bed::internal::commands

include/internal/commands/suffixes.h

@@ -1,13 +0,0 @@
-#pragma once
-
-#include "definitions.h"
-#include "pch.h"
-
-namespace bed::internal::commands {
-struct Suffix {
-  std::string desc;
-  void (*handle)(BEd &, std::span<const uint64_t>);
-
-  static void register_suffixes(BEd &ctx);
-};
-} // namespace bed::internal::commands

include/internal/functions/functions.h

@@ -0,0 +1,85 @@
+#pragma once
+
+#include "definitions.h"
+#include "internal/buffer/buffer.h"
+#include "internal/trie/trie.h"
+#include "pch.h"
+
+namespace bed::internal::functions {
+struct Function {
+  struct GlobalArg {
+    char delim;
+    std::string str;
+  };
+  struct RegexArg {
+    std::string expression;
+    std::string replacement;
+    std::string options;
+  };
+  struct ShellArg {
+    std::string cmd;
+  };
+  struct RubyArg {
+    std::string cmd;
+  };
+  using Argument = std::variant<
+    std::monostate,
+    GlobalArg,
+    RegexArg,
+    ShellArg,
+    RubyArg,
+    std::string,
+    std::filesystem::path,
+    int64_t,
+    char,
+    buffer::Range,
+    buffer::Line>;
+
+  enum struct AddressKind {
+    None,
+    Line,
+    Range
+  } address_kind;
+
+  enum struct ArgumentKind {
+    None,
+    Regex,
+    Shell,
+    Ruby,
+    Any,
+    File,
+    Number,
+    Mark,
+    Range,
+    Line,
+    Global
+  } argument_kind;
+
+  enum struct InputMode {
+    None,
+    Text,
+    Interactive,
+    CommandList
+  } input_mode;
+
+  std::string desc;
+  std::string default_address;
+  bool accept_zero;
+
+  std::function<
+    std::tuple<vase::Shard *, syntax::Language *, void *>(
+      BEd &ctx, const buffer::Address &addr, const Argument &arg
+    )>
+    pre_text_mode;
+
+  std::function<
+    void(
+      BEd &ctx, const buffer::Address &addr,
+      vase::Shard *text, const Argument &arg,
+      std::vector<buffer::Line> *marked
+    )>
+    handle;
+
+  static void register_posix(BEd &ctx);
+};
+} // namespace bed::internal::functions

include/internal/functions/suffixes.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "definitions.h"
+#include "internal/buffer/buffer.h"
+#include "pch.h"
+
+namespace bed::internal::functions {
+struct Suffix {
+  std::string desc;
+  std::function<void(BEd &)> handle;
+
+  static void register_suffixes(BEd &ctx);
+};
+} // namespace bed::internal::functions

include/internal/io/command.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include "internal/io/io.h"
+#include "internal/ui/autocomp.h"
+#include "pch.h"
+
+namespace bed::internal::io {
+struct Token {
+  enum struct Type : uint8_t {
+    TempCurrent,      // @
+    AddressSeperator, // ; ,
+    Address,          // . $ % [ ] ^ ~
+    Offset,           // +N -N + -
+    AddressRegex,     // /re/ ?re?
+    AddressSymbol,    // >s> <s< <s>
+    Number,           // 10
+    Mark,             // 'm
+    RubyFunction,     // (func:arg)
+    RubyArg,
+    Function,
+    Any,
+    Shell,
+    Ruby,
+    File,
+    Regex,
+    Replacement,
+    Suffix
+  } type;
+  uint16_t start;
+  uint16_t end;
+};
+
+struct CommandIO {
+  std::string cmd;
+  uint16_t cursor;
+  std::string prompt;
+  uint16_t start;
+  uint16_t height;
+  uint16_t term_height;
+  uint16_t term_width;
+  BEd &bed;
+  IO &io;
+
+  CommandIO(BEd &, IO &);
+  std::pair<std::string, bool> run();
+  void redraw();
+};
+} // namespace bed::internal::io

include/internal/io/io.h

@@ -11,7 +11,7 @@ struct KeyEvent {
     RESIZE
   };
   enum struct KeyType {
-    NONE,
+    EOF_,
     CHAR,
     SPECIAL,
     MOUSE,
@@ -38,7 +38,7 @@ struct KeyEvent {
     RELEASE
   };
 
-  KeyType type = KeyType::NONE;
+  KeyType type = KeyType::EOF_;
   std::string text;
 
   SpecialKey special_key = SpecialKey::UNKNOWN;
@@ -67,6 +67,8 @@ struct IO {
   std::pair<std::string, bool> get_text(BEd &);
 
   KeyEvent read_key();
+  void write(const char *, uint64_t);
+  void write(std::string_view);
 
 private:
   static termios orig_termios;

include/internal/marks/marks.h

@@ -1,55 +1,58 @@
 #pragma once
 
+#include "internal/buffer/buffer.h"
 #include "pch.h"
 
 namespace bed::internal::marks {
 struct MarksEngine {
-  uint64_t marks[256];
+  buffer::Line marks[256];
 
   MarksEngine() {
     for (auto &m : marks)
-      m = UINT64_MAX;
+      m = {"", UINT64_MAX};
   }
 
-  uint64_t get(uint8_t m) {
+  buffer::Line &get(uint8_t m) {
     return marks[m];
   }
 
-  void set(uint8_t m, uint64_t line) {
-    marks[m] = line;
-  }
-
-  void insert(uint64_t start, uint64_t count) {
+  void insert(std::string bufname, uint64_t start, uint64_t count) {
     for (uint16_t i = 0; i <= UINT8_MAX; ++i) {
-      if (marks[i] == UINT64_MAX)
+      if (marks[i].buffername != bufname)
         continue;
-      if (marks[i] >= start)
-        marks[i] += count;
+      if (marks[i].number == UINT64_MAX)
+        continue;
+      if (marks[i].number >= start)
+        marks[i].number += count;
     }
   }
 
-  void erase(uint64_t start, uint64_t count) {
+  void erase(std::string bufname, uint64_t start, uint64_t count) {
     for (uint16_t i = 0; i <= UINT8_MAX; ++i) {
-      if (marks[i] == UINT64_MAX)
+      if (marks[i].buffername != bufname)
         continue;
-      if (marks[i] >= start) {
-        if (marks[i] < start + count)
-          marks[i] = UINT64_MAX;
+      if (marks[i].number == UINT64_MAX)
+        continue;
+      if (marks[i].number >= start) {
+        if (marks[i].number < start + count)
+          marks[i].number = UINT64_MAX;
         else
-          marks[i] -= count;
+          marks[i].number -= count;
       }
     }
   }
 
-  void collapse(uint64_t start, uint64_t count) {
+  void collapse(std::string bufname, uint64_t start, uint64_t count) {
     for (uint16_t i = 0; i <= UINT8_MAX; ++i) {
-      if (marks[i] == UINT64_MAX)
+      if (marks[i].buffername != bufname)
         continue;
-      if (marks[i] >= start) {
-        if (marks[i] < start + count)
-          marks[i] = start;
+      if (marks[i].number == UINT64_MAX)
+        continue;
+      if (marks[i].number >= start) {
+        if (marks[i].number < start + count)
+          marks[i].number = start;
         else
-          marks[i] -= count;
+          marks[i].number -= count;
       }
     }
   }

include/internal/parser/parser.h

@@ -0,0 +1,114 @@
+#pragma once
+
+#include "internal/functions/functions.h"
+#include "internal/functions/suffixes.h"
+#include "internal/io/command.h"
+#include "pch.h"
+
+namespace bed::internal::parser {
+struct AddressPromise {
+  struct None {};    //
+  struct Current {}; // .
+  struct Last {};    // $
+  struct Number {    // n
+    uint64_t i;
+  };
+  struct Mark { // 'm
+    char m;
+  };
+  struct Regex { // /re/ or ?re?
+    internal::Direction dir;
+    std::string re;
+  };
+  struct Diagnostic { // ^ or ~ for previous/next diagnostic
+    internal::Direction dir;
+  };
+  struct SymbolDefinition { // <sym> goto symbol definition. (From lsp or using internal language parsers)
+    std::string sym;
+  };
+  struct SymbolReference {   // >sym> or <sym<
+    internal::Direction dir; // goto next or previous symbol reference
+    std::string sym;
+  };
+  struct Block { // [ or ] goto start/end of containing block.
+    internal::Direction dir;
+  };
+  struct Scripted {   // {function_name:arguments}
+    std::string func; // Calls ruby mapping with name giving the argument as string.
+    std::string arg;  // resolves to line number returned by function (or throws error).
+                      // The mruby runtime also has the full context of the file and extentions etc.
+  };
+  struct LastRange {}; // % , refers to last used range
+
+  std::optional<std::string> bufname;
+  std::variant<
+    None,
+    Current,
+    Last,
+    Number,
+    Mark,
+    Regex,
+    Diagnostic,
+    SymbolDefinition,
+    SymbolReference,
+    Block,
+    Scripted,
+    LastRange>
+    base{};
+  int64_t offset = 0;
+  bool jumping{false}; // ; == jumping and , == non jumping
+  buffer::Line resolve(BEd &ctx);
+  static std::optional<buffer::Line> get_line(BEd &ctx, std::vector<AddressPromise> &);
+  static std::optional<buffer::Range> get_range(BEd &ctx, std::vector<AddressPromise> &);
+};
+
+struct Command {
+  bool temp_address{false};
+  std::vector<AddressPromise> addresses{};
+  functions::Function *function;
+  functions::Function::Argument argument;
+  std::vector<AddressPromise> argument_addresses{};
+  functions::Suffix *suffix;
+};
+
+struct CompletionContext {
+  enum {
+    Error,
+    Valid,
+    Incomplete
+  } error;
+  // TODO: store a state of typing context to think about possible completions.
+};
+
+struct Parser {
+  BEd &bed;
+  std::string_view cmd;
+  uint16_t i;
+  Command *command;
+  std::vector<io::Token> *tokens;
+  CompletionContext *completion;
+
+  explicit Parser(
+    std::string_view cmd, BEd &bed, Command *command,
+    std::vector<io::Token> *tokens, CompletionContext *completion
+  );
+
+  char peek(uint16_t = 0); // == \0 if at eof.
+  std::string_view peek_str(uint16_t = UINT16_MAX);
+  void advance(uint16_t = 1);
+
+  void skip_ws();
+
+  void locator(AddressPromise &);
+  int64_t offset();
+  void address(AddressPromise &addr);
+  void addresses(std::vector<AddressPromise> &addresses);
+
+  void operation();
+
+  void parse();
+
+  static Command get_command(std::string_view, BEd &);
+  static std::vector<AddressPromise> get_addresses(std::string_view cmd, BEd &bed);
+};
+} // namespace bed::internal::parser

include/internal/syntax/parser.h

@@ -13,15 +13,15 @@ struct Parser {
   ParseState *root;
   Language lang;
 
-  Parser(vase::Vase &, uint64_t, Language);
+  Parser(vase::Shard *, uint64_t, Language);
   ~Parser();
   Parser(const Parser &) = delete;
   Parser &operator=(const Parser &) = delete;
 
-  void reset(vase::Vase &, uint64_t, Language);
-  void erase(vase::Vase &, uint64_t, uint64_t);
-  void insert(vase::Vase &, uint64_t, uint64_t);
-  void modify(vase::Vase &, uint64_t, uint64_t);
+  void reset(vase::Shard *, uint64_t, Language);
+  void erase(vase::Shard *, uint64_t, uint64_t);
+  void insert(vase::Shard *, uint64_t, uint64_t);
+  void modify(vase::Shard *, uint64_t, uint64_t);
 
   uint64_t next_closing(uint64_t line);
   uint64_t prev_opening(uint64_t line);
@@ -36,7 +36,7 @@ struct Parser {
     uint64_t at;
     std::vector<Token> tokens;
     std::vector<ParseEvent> events;
-    Iterator(uint64_t, Parser *, vase::Vase &);
+    Iterator(uint64_t, Parser *, vase::Shard *);
     ~Iterator();
     Iterator(const Iterator &) = delete;
     Iterator &operator=(const Iterator &) = delete;
@@ -44,6 +44,6 @@ struct Parser {
     Iterator &operator=(Iterator &&other);
     void next();
   };
-  std::optional<Iterator> get_hl(vase::Vase &, uint64_t);
+  std::optional<Iterator> get_hl(vase::Shard *, uint64_t);
 };
 } // namespace bed::internal::syntax

include/internal/trie/trie.h

@@ -147,7 +147,7 @@ struct Trie {
   }
 
   static void collect(
-    const Node &node,
+    Node &node,
     std::string &key,
     std::vector<SearchResult> &result
   ) {
@@ -228,6 +228,44 @@ struct Trie {
     return *current->value;
   }
 
+  V *get_ptr(std::string_view key) {
+    Node *current = &root;
+    uint64_t pos = 0;
+    while (pos < key.size()) {
+      Node *child = find_child(*current, key[pos]);
+      if (!child)
+        return nullptr;
+      const auto remaining = key.substr(pos);
+      const auto common = common_prefix(child->edge, remaining);
+      if (common != child->edge.size())
+        return nullptr;
+      pos += common;
+      current = child;
+    }
+    if (!current->value)
+      return nullptr;
+    return &*current->value;
+  }
+
+  const V *get_ptr(std::string_view key) const {
+    const Node *current = &root;
+    uint64_t pos = 0;
+    while (pos < key.size()) {
+      const Node *child = find_child(*current, key[pos]);
+      if (!child)
+        return nullptr;
+      const auto remaining = key.substr(pos);
+      const auto common = common_prefix(child->edge, remaining);
+      if (common != child->edge.size())
+        return nullptr;
+      pos += common;
+      current = child;
+    }
+    if (!current->value)
+      return nullptr;
+    return &*current->value;
+  }
+
   bool equal_char(char a, char b) const {
     if (case_sensitive)
       return a == b;

include/internal/vase/buffer/original.h

@@ -1,19 +0,0 @@
-#pragma once
-
-#include "buffer.h"
-#include "pch.h"
-
-namespace bed::internal::vase {
-struct OriginalBuffer : Buffer {
-  const char *buf;
-  uint64_t len;
-  int fd = -1;
-
-  OriginalBuffer(std::filesystem::path base_dir);
-  ~OriginalBuffer();
-
-  void initialize();
-  const char *read(uint64_t pos) override;
-  uint64_t length() override;
-};
-} // namespace bed::internal::vase

include/internal/vase/shard.h

@@ -1,9 +1,9 @@
 #pragma once
 
-#include "buffer/buffer.h"
-#include "buffer/original.h"
 #include "constants.h"
 #include "pch.h"
+#include "storage/original.h"
+#include "storage/storage.h"
 
 namespace bed::internal::vase {
 struct Shard {
@@ -24,9 +24,10 @@ struct Shard {
   static void retain(Shard *n);
   static void release(Shard *n);
 
-  static Shard *from_file(std::filesystem::path &path, OriginalBuffer *b, bool posix_ending);
-  static Shard *from_command(const char *cmd, OriginalBuffer *o, bool posix_ending);
-  static std::vector<Shard *> from_swap(std::filesystem::path &path, OriginalBuffer *b);
+  static Shard *from_file(const std::filesystem::path &path, bool posix_ending);
+  static Shard *from_string(const char *data, uint64_t len, bool posix_ending);
+  static Shard *from_command(const char *cmd, bool posix_ending);
+  // static std::vector<Shard *> from_swap(std::filesystem::path &path, OriginalStorage *b);
 
   static std::pair<Shard *, Shard *> split(Shard *n, uint64_t offset);
   static Shard *concat(Shard *a, Shard *b);
@@ -54,12 +55,14 @@ struct Branch : Shard {
 };
 
 struct Petal : Shard {
-  Buffer *source;
+  Storage *source;
   uint64_t pos;
 
-  Petal(uint64_t length, uint64_t lines, Buffer *source, uint64_t pos)
+  Petal(uint64_t length, uint64_t lines, Storage *source, uint64_t pos)
       : Shard(Kind::Petal, length, lines, 1),
-        source(source), pos(pos) {};
+        source(source), pos(pos) {
+    source->retain();
+  };
 };
 
 } // namespace bed::internal::vase

include/internal/vase/storage/append.h

@@ -1,24 +1,27 @@
 #pragma once
 
 #include "../constants.h"
-#include "buffer.h"
 #include "pch.h"
+#include "storage.h"
 
 namespace bed::internal::vase {
-struct AppendBuffer : Buffer {
+struct AppendStorage : Storage {
   char *buf = nullptr;
   uint64_t allocated_capacity = 0;
   uint64_t current_size = 0;
   int fd = -1;
 
-  AppendBuffer(std::filesystem::path base_dir);
-  ~AppendBuffer();
+  AppendStorage(std::filesystem::path base_dir);
+  ~AppendStorage();
 
   uint64_t append(const char c);
   uint64_t append(const char *text, uint64_t len);
   const char *read(uint64_t pos) override;
   uint64_t length() override;
 
+  void retain() override {}
+  void release() override {}
+
 private:
   void grow(uint64_t len);
 };

include/internal/vase/storage/original.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "pch.h"
+#include "storage.h"
+
+namespace bed::internal::vase {
+struct OriginalStorage : Storage {
+  std::atomic_uint64_t refs{0};
+  const char *buf = nullptr;
+  uint64_t len = 0;
+  int fd = -1;
+
+  OriginalStorage(std::filesystem::path base_dir);
+  ~OriginalStorage();
+
+  void initialize();
+  const char *read(uint64_t pos) override;
+  uint64_t length() override;
+
+  void retain() override {
+    refs++;
+  }
+
+  void release() override {
+    if (--refs > 0)
+      return;
+    delete this;
+  }
+};
+} // namespace bed::internal::vase

include/internal/vase/storage/storage.h

@@ -3,9 +3,11 @@
 #include "pch.h"
 
 namespace bed::internal::vase {
-struct Buffer {
+struct Storage {
   virtual const char *read(uint64_t pos) = 0;
   virtual uint64_t length() = 0;
-  virtual ~Buffer() = default;
+  virtual ~Storage() = default;
+  virtual void retain() = 0;
+  virtual void release() = 0;
 };
 } // namespace bed::internal::vase

include/internal/vase/vase.h

@@ -1,12 +1,12 @@
 #pragma once
 
-#include "buffer/append.h"
-#include "buffer/original.h"
 #include "constants.h"
 #include "definitions.h"
 #include "iterators/line.h"
 #include "pch.h"
 #include "shard.h"
+#include "storage/append.h"
+#include "storage/original.h"
 
 namespace bed::internal::vase {
 struct Point {
@@ -19,103 +19,57 @@ struct Range {
   Point end;
 };
 
-struct Vase {
-  struct RegexGroup {
-    uint64_t start{0};
-    uint64_t end{0};
-  };
-
-  struct RegexMatch {
-    uint64_t start;
-    uint64_t end;
-    RegexGroup groups[9]{};
-  };
-
-  struct ReplacePart {
-    enum struct PartType {
-      FullMatch,
-      CaptureGroup,
-      Constant
-    } type;
-
-    std::variant<uint8_t, Shard *> value;
-  };
-
-  OriginalBuffer *original;
-  AppendBuffer *append;
-  Shard *root;
-
-#ifdef _WIN32
-  bool posix_ending = false;
-  bool using_crlf = true;
-#else
-  bool posix_ending = true;
-  bool using_crlf = false;
-#endif
-
-  std::filesystem::path path;
-  std::filesystem::path swapdir;
-
-  Vase(std::filesystem::path path, std::filesystem::path swapdir);
-  Vase(std::string cmd, std::filesystem::path swapdir);
-  Vase(std::filesystem::path swapdir);
-  ~Vase();
-  Vase(Vase &&other) noexcept;
-  Vase &operator=(Vase &&other) noexcept;
-  Vase(const Vase &) = delete;
-  Vase &operator=(const Vase &) = delete;
-
-  uint64_t length();
-  uint64_t lines();
-  std::string to_string();
-  std::string to_string(Range range);
-
-  Iterator iterate(uint64_t line, Direction dir);
-
-  void insert(Point *point, char key);
-  void insert(Point *point, std::string_view str);
-  void insert(Point *point, const char *data, uint64_t len);
-  void erase(Point *point, uint64_t amount, Direction dir);
-  void erase(Range range);
-  void replace(Range range, std::string_view str);
-  void replace(Range range, const char *data, uint64_t len);
-
-  void move_clusters(Point *point, uint64_t amount, Direction dir);
-  void move_lines(Point *point, uint64_t amount, Direction dir);
-  void clamp(Point *point);
-
-  void regex_search_replace(
-    std::string_view pattern, Range range,
-    std::string_view replace, std::string_view options
-  );
-
-  std::vector<Range> regex_search(
-    std::string_view pattern, Range range, std::string_view options
-  );
-
-  uint64_t find_next(std::string_view pattern, uint64_t start);
-  uint64_t find_prev(std::string_view pattern, uint64_t start);
-
-  bool undo();
-  bool redo();
-  void snapshot();
-  void prune_history(uint64_t n);
-
-  bool save();
-  bool save_swap();
-
-  uint64_t offset_of(Point point);
-  Point point_of(uint64_t offset);
-
-private:
-  std::vector<Shard *> history;
-  uint64_t history_top;
-
-  void _insert(Point *point, const char *data, uint64_t len);
-
-  std::vector<ReplacePart> parse_replace(std::string_view s);
-  std::vector<RegexMatch> _regex_search(
-    std::string_view pattern, Range range, std::string_view options
-  );
+struct RegexGroup {
+  uint64_t start{0};
+  uint64_t end{0};
 };
+
+struct RegexMatch {
+  uint64_t start;
+  uint64_t end;
+  RegexGroup groups[9]{};
+};
+
+struct ReplacePart {
+  enum struct PartType {
+    FullMatch,
+    CaptureGroup,
+    Constant
+  } type;
+  std::variant<uint8_t, Shard *> value;
+};
+
+uint64_t offset_of(Shard *root, uint64_t line);
+uint64_t offset_of(Shard *root, Point point);
+Point point_of(Shard *root, uint64_t offset);
+
+std::string to_string(Shard *root);
+std::string to_string(Shard *root, Range range);
+
+Shard *insert(AppendStorage *ap, Shard *root, Shard *text, uint64_t line);
+Shard *erase(Shard *root, uint64_t start, uint64_t end);
+Shard *copy(Shard *root, uint64_t start, uint64_t end);
+
+uint64_t find_next(Shard *root, std::string_view pattern, uint64_t start);
+uint64_t find_prev(Shard *root, std::string_view pattern, uint64_t start);
+
+Shard *substitute(
+  AppendStorage *ap, Shard *root,
+  std::string_view pattern, uint64_t start, uint64_t end,
+  std::string_view replace, std::string_view options
+);
+
+// internal
+
+void _insert(AppendStorage *ap, Shard **root, Point *point, const char *data, uint64_t len);
+Shard *insert(AppendStorage *ap, Shard *root, Point *point, char key);
+Shard *insert(AppendStorage *ap, Shard *root, Point *point, const char *data, uint64_t len);
+
+Shard *erase(Shard *root, Range range);
+Shard *replace(AppendStorage *ap, Shard *root, Range range, const char *data, uint64_t len);
+
+std::vector<ReplacePart> parse_replace(AppendStorage *ap, std::string_view s);
+std::vector<RegexMatch> _regex_search(
+  Shard *root, std::string_view pattern, uint64_t start_offset, uint64_t end_offset, std::string_view options
+);
 } // namespace bed::internal::vase