Major updates/cleanup.

flake.nix

@@ -113,6 +113,7 @@
           export MRBC=${mruby}/bin/mrbc
           export MRUBY_CFLAGS=-I${mruby}/include
           export MRUBY_LIBS="-L${mruby}/lib -lmruby"
+          export PATH="$PWD/result/bin:$PATH"
         '';
       };
     };

include/bed.h

@@ -26,6 +26,7 @@ struct BEd {
   bool prompt_mode = true;
   std::function<std::string(BEd &)> prompt = nullptr;
   bool suppress_mode = false;
+  bool color_mode = false;
   bool temporary_current = false;
   std::string last_help = "";
   std::string last_regex = "";

include/internal/io/tokens.h

@@ -17,7 +17,6 @@ struct Token {
     RubyFunction,
     RubyArg,
     Function,
-    Any,
     Shell,
     File,
     Suffix,

include/internal/parser/parser.h

@@ -93,6 +93,9 @@ struct Parser {
     std::vector<io::Token> *tokens, CompletionContext *completion
   );
 
+  void token(io::Token::Kind);
+  void end_token();
+
   char peek(uint16_t = 0); // == \0 if at eof.
   std::string_view peek_str(uint16_t = UINT16_MAX);
   void advance(uint16_t = 1);

include/internal/syntax/miniparser.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "decl.h"
+
+namespace bed::internal::syntax {
+struct MiniParser {
+  Language ⟨
+  void *start_state;
+  std::vector<std::pair<void *, std::vector<io::Token>>> lines;
+
+  explicit MiniParser(Language &lang, vase::Shard *vase, void *initial_state);
+  ~MiniParser();
+
+  MiniParser(const MiniParser &) = delete;
+  MiniParser &operator=(const MiniParser &) = delete;
+
+  void dirty(vase::Shard *vase, uint64_t start, uint64_t count);
+  void insert(vase::Shard *vase, uint64_t start, uint64_t count);
+  void erase(vase::Shard *vase, uint64_t start, uint64_t count);
+};
+} // namespace bed::internal::syntax

include/internal/ui/text_mode.h

@@ -1,23 +1,31 @@
 #pragma once
 
-#include "definitions.h"
+#include "internal/syntax/miniparser.h"
 #include "pch.h"
 
-namespace bed::internal::ui {
+namespace bed::internal::ui::text_mode {
 struct TextMode {
-  std::string cmd;
-  uint16_t cursor;
+  struct Row {
+    uint64_t start;
+    uint64_t length;
+  };
+  using Lines = std::vector<Row>;
+  vase::Shard *vase;
+  vase::Point cursor;
+  std::optional<syntax::MiniParser> parser;
+  std::vector<Lines> lines;
   uint16_t start;
   uint16_t height;
   uint16_t term_height;
   uint16_t term_width;
   BEd &bed;
 
-  TextMode(BEd &);
+  TextMode(BEd &, vase::Shard *, syntax::Language *, void *);
   std::pair<vase::Shard *, bool> run();
   std::pair<vase::Shard *, bool> run_pipe();
   std::pair<vase::Shard *, bool> run_terminal();
   void grow();
   void redraw();
+  void layout_lines();
 };
-} // namespace bed::internal::ui
+} // namespace bed::internal::ui::text_mode

include/internal/vase/vase.h

@@ -41,7 +41,7 @@ struct ReplacePart {
 
 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);
+Point eof_point(Shard *root);
 
 std::string to_string(Shard *root);
 std::string to_string(Shard *root, Range range);

src/bed/run.cc

@@ -7,6 +7,7 @@ BEd::BEd(std::vector<std::string> args)
   std::string prompt_ = "";
   std::string file = "";
   bool suppress = false;
+  bool color = true;
   for (size_t i = 1; i < args.size(); i++) {
     if (args[i] == "-p") {
       i++;
@@ -15,6 +16,8 @@ BEd::BEd(std::vector<std::string> args)
       prompt_ = args[i];
     } else if (args[i] == "-s") {
       suppress = true;
+    } else if (args[i] == "--no-color") {
+      color = false;
     } else if (args[i] == "-v" || args[i] == "--verbose") {
       help_mode = true;
     } else if (args[i] == "-h" || args[i] == "--help") {
@@ -31,6 +34,15 @@ BEd::BEd(std::vector<std::string> args)
   else
     prompt_mode = false;
   suppress_mode = suppress;
+  const char *no_color = getenv("NO_COLOR");
+  if (no_color && *no_color != '\0')
+    color = false;
+  const char *colorterm = getenv("COLORTERM");
+  if (colorterm
+      && strcmp(colorterm, "truecolor") != 0
+      && strcmp(colorterm, "24bit") != 0)
+    color = false;
+  color_mode = color;
   internal::functions::Function::register_posix(*this);
   internal::functions::Function::register_extented(*this);
   internal::functions::Suffix::register_suffixes(*this);
@@ -77,7 +89,7 @@ void BEd::run() {
 }
 
 void BEd::handle(std::string_view cmd, bool eof) {
-  if (eof) {
+  if (eof && cmd.empty()) {
     eof_op.handle(*this, "", nullptr, std::monostate(), nullptr);
     return;
   }
@@ -149,10 +161,17 @@ void BEd::handle(std::string_view cmd, bool eof) {
   }
   internal::vase::Shard *text = nullptr;
   if (c.function->input_mode == internal::functions::Function::InputMode::Text) {
-    internal::ui::TextMode tm(*this);
+    internal::vase::Shard *vase = nullptr;
+    internal::syntax::Language *lang = nullptr;
+    void *state = nullptr;
+    if (c.function->pre_text_mode)
+      std::tie(vase, lang, state) = c.function->pre_text_mode(*this, address, c.argument);
+    internal::ui::text_mode::TextMode tm(*this, vase, lang, state);
     auto [a, b] = tm.run();
     if (!b)
       text = a;
+    else
+      internal::vase::Shard::release(a);
   }
   if (c.function->handle)
     c.function->handle(*this, address, text, c.argument, nullptr);

src/internal/buffer/special/clip.cc

@@ -94,7 +94,6 @@ void ClipBuffer::replace(BEd &ctx, vase::Shard *text, uint64_t start_line, uint6
     uint64_t diff = old_count - new_count;
     ctx.marks.collapse(name, start_line + new_count - 1, diff);
   }
-  state = Modified;
 }
 
 void ClipBuffer::join(BEd &ctx, uint64_t start_line, uint64_t end_line) {

src/internal/functions/posix.cc

@@ -60,7 +60,21 @@ void Function::register_posix(BEd &ctx) {
       .desc = "Change a range of lines",
       .default_address = ".,.",
       .accept_zero = false,
-      .pre_text_mode = nullptr,
+      .pre_text_mode = [](
+                         BEd &ctx,
+                         const buffer::Address &addr_,
+                         const Argument &
+                       ) -> std::tuple<vase::Shard *, syntax::Language *, void *> {
+        const auto &addr = std::get<buffer::Range>(addr_);
+        auto &buf_ = ctx.buffer(addr.buffername);
+        if (buf_.kind != buffer::Buffer::Kind::Generic)
+          return {buf_.copy(addr.start, addr.end), nullptr, nullptr};
+        auto &buf = *(buffer::GenericBuffer *)&buf_;
+        if (!buf.parse.lang)
+          return {buf.copy(addr.start, addr.end), nullptr, nullptr};
+        void *state = nullptr; // TODO: buf.parse.root.get_at(addr.start);
+        return {buf.copy(addr.start, addr.end), buf.parse.lang, state};
+      },
       .handle = [](
                   BEd &ctx,
                   const buffer::Address &addr_,
@@ -68,10 +82,9 @@ void Function::register_posix(BEd &ctx) {
                   const Argument &,
                   std::vector<buffer::Line> *
                 ) {
-        auto addr = std::get<buffer::Range>(addr_);
+        const auto &addr = std::get<buffer::Range>(addr_);
         ctx.buffer(addr.buffername).replace(ctx, text, addr.start, addr.end);
-        vase::Shard::release(text);
-      }
+        vase::Shard::release(text); }
     }
   );
   ctx.functions.insert(

src/internal/io/input.cc

@@ -16,9 +16,11 @@ std::pair<std::string, bool> IO::read_pipe() {
       continue;
     }
     if (n == 0) {
+      if (pipe_input.empty())
+        return {"", true};
       std::string line = std::move(pipe_input);
       pipe_input.clear();
-      return {line, true};
+      return {line, false};
     }
     if (errno == EINTR)
       continue;

src/internal/io/io.cc

@@ -35,7 +35,7 @@ IO::~IO() {
 }
 
 void IO::apply(const io::Token::Kind &t) {
-  if (bed.suppress_mode)
+  if (!bed.color_mode)
     return;
   write("\x1b[0m");
   const auto &hl = bed.theme.get(t);
@@ -60,7 +60,7 @@ void IO::apply(const io::Token::Kind &t) {
 }
 
 void IO::reset() {
-  if (bed.suppress_mode)
+  if (!bed.color_mode)
     return;
   write("\x1b[0m");
 }

src/internal/parser/address.cc

@@ -6,74 +6,49 @@ void Parser::locator(AddressPromise &addr) {
   addr.base = AddressPromise::None{};
   switch (peek()) {
   case '.':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::Current{};
     break;
   case '$':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::Last{};
     break;
   case '%':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::LastRange{};
     break;
   case '[':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::Block{Direction::Backward};
     break;
   case ']':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::Block{Direction::Forward};
     break;
   case '^':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::Diagnostic{Direction::Backward};
     break;
   case '~':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::Diagnostic{Direction::Forward};
     break;
   case '\'':
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)2,
-       .type = io::Token::Mark}
-    );
+    token(io::Token::Mark);
     advance();
     if (('a' <= peek() && peek() <= 'z')
         || ('A' <= peek() && peek() <= 'Z'))
@@ -81,17 +56,16 @@ void Parser::locator(AddressPromise &addr) {
     else
       throw ed_error("Valid mark needed after \'");
     advance();
+    end_token();
     break;
   case '{': {
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     uint16_t j = 0;
     std::string func;
     std::string arg;
+    token(io::Token::RubyFunction);
     while (peek(j) != '}') {
       if (peek(j) == '\0')
         throw ed_error("Scripted address not terminated");
@@ -100,6 +74,8 @@ void Parser::locator(AddressPromise &addr) {
       if (peek(j) == ':') {
         func = peek_str(j);
         advance(j + 1);
+        end_token();
+        token(io::Token::RubyArg);
         j = 0;
         continue;
       }
@@ -109,26 +85,15 @@ void Parser::locator(AddressPromise &addr) {
       arg = peek_str(j);
     else
       func = peek_str(j);
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)func.size(),
-       .type = io::Token::RubyFunction}
-    );
-    if (arg.size())
-      tokens->push_back(
-        {.start = i + (uint64_t)func.size() + 1,
-         .end = i + (uint64_t)func.size() + 1 + (uint64_t)arg.size(),
-         .type = io::Token::RubyFunction}
-      );
     addr.base = AddressPromise::Scripted{std::move(func), std::move(arg)};
-    advance(j + 1);
-    tokens->push_back(
-      {.start = i,
-       .end = i - (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    advance(j);
+    end_token();
+    token(io::Token::AddressSymbol);
+    advance();
+    end_token();
   } break;
   case '/': {
+    token(io::Token::Regexp);
     advance();
     uint64_t j = 0;
     while (true) {
@@ -148,19 +113,11 @@ void Parser::locator(AddressPromise &addr) {
       Direction::Forward,
       std::string(peek_str(j))
     );
-    tokens->push_back(
-      {.start = (uint64_t)i - 1,
-       .end = (uint64_t)i + j + 1,
-       .type = io::Token::Regexp}
-    );
     advance(j + 1);
+    end_token();
   } break;
   case '?': {
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::Regexp);
     advance();
     uint16_t j = 0;
     while (true) {
@@ -180,14 +137,11 @@ void Parser::locator(AddressPromise &addr) {
       Direction::Backward,
       std::string(peek_str(j))
     );
-    tokens->push_back(
-      {.start = (uint64_t)i - 1,
-       .end = (uint64_t)i + j + 1,
-       .type = io::Token::Regexp}
-    );
     advance(j + 1);
+    end_token();
   } break;
   case '<': {
+    token(io::Token::Label);
     advance();
     uint16_t j = 0;
     while (peek(j) != '>'
@@ -208,14 +162,11 @@ void Parser::locator(AddressPromise &addr) {
       };
       break;
     }
-    tokens->push_back(
-      {.start = (uint64_t)i - 1,
-       .end = (uint64_t)i + j + 1,
-       .type = io::Token::AddressSymbol}
-    );
     advance(j + 1);
+    end_token();
   } break;
   case '>': {
+    token(io::Token::Label);
     advance();
     uint16_t j = 0;
     while (peek(j) != '>' && peek(j) != '\0')
@@ -230,20 +181,13 @@ void Parser::locator(AddressPromise &addr) {
       };
       break;
     }
-    tokens->push_back(
-      {.start = (uint64_t)i - 1,
-       .end = (uint64_t)i + j + 1,
-       .type = io::Token::AddressSymbol}
-    );
     advance(j + 1);
+    end_token();
   } break;
   case '+': {
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
     addr.base = AddressPromise::Current{};
     uint16_t j = 0;
     uint64_t num = 0;
@@ -253,21 +197,15 @@ void Parser::locator(AddressPromise &addr) {
     }
     if (j == 0)
       num = 1;
-    tokens->push_back(
-      {.start = (uint64_t)i,
-       .end = (uint64_t)i + j,
-       .type = io::Token::Number}
-    );
-    advance(j);
     addr.offset += num;
+    advance(j);
+    end_token();
   } break;
   case '-': {
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSymbol}
-    );
+    token(io::Token::AddressSymbol);
     advance();
+    end_token();
+    token(io::Token::Number);
     addr.base = AddressPromise::Current{};
     uint16_t j = 0;
     uint64_t num = 0;
@@ -277,28 +215,20 @@ void Parser::locator(AddressPromise &addr) {
     }
     if (j == 0)
       num = 1;
-    tokens->push_back(
-      {.start = (uint64_t)i,
-       .end = (uint64_t)i + j,
-       .type = io::Token::Number}
-    );
-    advance(j);
     addr.offset -= num;
+    advance(j);
+    end_token();
   } break;
   default:
     if ('0' <= peek() && peek() <= '9') {
-      uint16_t start = i;
+      token(io::Token::Number);
       uint64_t num = 0;
       while ('0' <= peek() && peek() <= '9') {
         num = num * 10 + (peek() - '0');
         advance();
       }
       addr.base = AddressPromise::Number{num};
-      tokens->push_back(
-        {.start = (uint64_t)start,
-         .end = (uint64_t)i,
-         .type = io::Token::Number}
-      );
+      end_token();
     }
   }
 }
@@ -308,26 +238,19 @@ int64_t Parser::offset() {
   while (peek() == '+' || peek() == '-'
          || ('0' <= peek() && peek() <= '9')) {
     bool positive = peek() != '-';
-    if (peek() == '+' || peek() == '-') {
-      tokens->push_back(
-        {.start = i,
-         .end = i + (uint64_t)1,
-         .type = io::Token::AddressSymbol}
-      );
+    token(io::Token::AddressSymbol);
+    if (peek() == '+' || peek() == '-')
       advance();
-    }
+    end_token();
+    token(io::Token::Number);
     uint16_t j = 0;
     int64_t num = 0;
     while ('0' <= peek(j) && peek(j) <= '9')
       num = num * 10 + (peek(j++) - '0');
     if (j == 0)
       num = 1;
-    tokens->push_back(
-      {.start = (uint64_t)i,
-       .end = (uint64_t)i + j,
-       .type = io::Token::Number}
-    );
     advance(j);
+    end_token();
     offset += positive ? num : -num;
     skip_ws();
   }
@@ -337,7 +260,7 @@ int64_t Parser::offset() {
 
 void Parser::address(AddressPromise &addr) {
   if (peek() == ':') {
-    uint16_t start = i;
+    token(io::Token::BufferName);
     advance();
     uint16_t j = 0;
     while (peek(j) != ':' && peek(j) != '\0')
@@ -346,11 +269,7 @@ void Parser::address(AddressPromise &addr) {
     advance(j);
     if (peek() == ':')
       advance();
-    tokens->push_back(
-      {.start = start,
-       .end = i,
-       .type = io::Token::BufferName}
-    );
+    end_token();
   }
   skip_ws();
   if (peek() == '\0')
@@ -367,11 +286,7 @@ void Parser::addresses(std::vector<AddressPromise> &addresses) {
   address(*addr);
   while (peek() == ',' || peek() == ';') {
     addr->jumping = peek() == ';';
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::AddressSeperator}
-    );
+    token(io::Token::AddressSeperator);
     advance();
     skip_ws();
     addresses.push_back({});

src/internal/parser/address_promise.cc

@@ -81,16 +81,10 @@ std::optional<buffer::Line> AddressPromise::get_line(BEd &ctx, std::vector<Addre
   AddressPromise prev;
   for (std::size_t idx = 0; idx < list.size(); idx++) {
     AddressPromise &curr = list[idx];
-    if (curr.bufname.has_value()) {
-      if (curr.bufname->empty()) {
-        bufname = ctx.current().buffername;
+    if (!curr.bufname.has_value())
       curr.bufname = bufname;
-      } else {
-        bufname = *curr.bufname;
-      }
-    } else {
-      curr.bufname = bufname;
-    }
+    else if (curr.bufname->empty())
+      curr.bufname = bufname = ctx.current().buffername;
     bool is_final = idx + 1 == list.size();
     if (!is_final) {
       if (std::holds_alternative<None>(curr.base)) {
@@ -107,15 +101,15 @@ std::optional<buffer::Line> AddressPromise::get_line(BEd &ctx, std::vector<Addre
       } else {
         prev_given = true;
       }
-      if (curr.jumping) {
       buffer::Line resolved = curr.resolve(ctx);
+      if (curr.jumping)
         ctx.current() = resolved;
       curr.bufname = resolved.buffername;
       curr.base = Number(resolved.number);
       curr.offset = 0;
-      }
       prev = curr;
       prev_set = true;
+      bufname = *curr.bufname;
     } else {
       if (std::holds_alternative<None>(curr.base)) {
         if (prev_set) {
@@ -144,16 +138,10 @@ std::optional<buffer::Range> AddressPromise::get_range(BEd &ctx, std::vector<Add
   AddressPromise prev;
   for (std::size_t idx = 0; idx < list.size(); idx++) {
     AddressPromise &curr = list[idx];
-    if (curr.bufname.has_value()) {
-      if (curr.bufname->empty()) {
-        bufname = ctx.current().buffername;
+    if (!curr.bufname.has_value())
       curr.bufname = bufname;
-      } else {
-        bufname = *curr.bufname;
-      }
-    } else {
-      curr.bufname = bufname;
-    }
+    else if (curr.bufname->empty())
+      curr.bufname = bufname = ctx.current().buffername;
     bool is_final = idx + 1 == list.size();
     if (!is_final) {
       if (std::holds_alternative<None>(curr.base)) {
@@ -170,15 +158,15 @@ std::optional<buffer::Range> AddressPromise::get_range(BEd &ctx, std::vector<Add
       } else {
         prev_given = true;
       }
-      if (curr.jumping) {
       buffer::Line resolved = curr.resolve(ctx);
-        ctx.current() = resolved;
       curr.bufname = resolved.buffername;
       curr.base = Number(resolved.number);
       curr.offset = 0;
-      }
+      if (curr.jumping)
+        ctx.current() = resolved;
       prev = curr;
       prev_set = true;
+      bufname = *curr.bufname;
     } else {
       if (std::holds_alternative<None>(curr.base)) {
         if (prev_set) {

src/internal/parser/operation.cc

@@ -11,12 +11,9 @@ void Parser::operation() {
   if (len == 0)
     throw ed_error("Function not found.");
   functions::Function *function = bed.functions.get_ptr(peek_str(len));
-  tokens->push_back(
-    {.start = i,
-     .end = i + len,
-     .type = io::Token::Function}
-  );
+  token(io::Token::Function);
   advance(len);
+  end_token();
   command->function = function;
   char suffix = '\0';
   switch (command->function->argument_kind) {
@@ -32,21 +29,15 @@ void Parser::operation() {
       command->argument = peek();
     else
       throw ed_error("Valid mark needed.");
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::Mark}
-    );
+    token(io::Token::Mark);
     advance();
+    end_token();
     break;
   case functions::Function::ArgumentKind::Any:
     command->argument = std::string(peek_str());
-    tokens->push_back(
-      {.start = i,
-       .end = i + peek_str().size(),
-       .type = io::Token::Any}
-    );
+    token(io::Token::Data);
     advance(peek_str().size());
+    end_token();
     break;
   case functions::Function::ArgumentKind::Global: {
     char delim;
@@ -123,31 +114,22 @@ void Parser::operation() {
     skip_ws();
     switch (peek()) {
     case '!':
-      tokens->push_back(
-        {.start = i,
-         .end = (uint64_t)i + 1,
-         .type = io::Token::Error}
-      );
+      token(io::Token::Error);
       advance();
+      end_token();
+      token(io::Token::Shell);
       command->argument = functions::Function::ShellArg(std::string(peek_str()));
-      tokens->push_back(
-        {.start = i,
-         .end = i + peek_str().size(),
-         .type = io::Token::Shell}
-      );
       advance(peek_str().size());
+      end_token();
       break;
     case '\0':
       command->argument = std::monostate();
       break;
     default:
+      token(io::Token::File);
       command->argument = std::filesystem::path(peek_str());
-      tokens->push_back(
-        {.start = i,
-         .end = i + peek_str().size(),
-         .type = io::Token::File}
-      );
       advance(peek_str().size());
+      end_token();
       break;
     }
     break;
@@ -163,7 +145,7 @@ void Parser::operation() {
     char delim = peek();
     if (delim == '\0')
       throw ed_error("regex expected");
-    uint16_t start = i;
+    token(io::Token::Regexp);
     advance();
     uint16_t j = 0;
     while (true) {
@@ -203,20 +185,13 @@ void Parser::operation() {
       advance(j);
       options = "p";
     }
-    tokens->push_back(
-      {.start = start,
-       .end = i,
-       .type = io::Token::Regexp}
-    );
+    end_token();
+    token(io::Token::Suffix);
     if (peek() != '\0') {
       options = std::string(peek_str());
-      tokens->push_back(
-        {.start = i,
-         .end = i + peek_str().size(),
-         .type = io::Token::Suffix}
-      );
       advance(peek_str().size());
     }
+    end_token();
     std::erase_if(options, [&](char c) {
       if (bed.suffixes[c - 'a'].has_value()) {
         suffix = c;
@@ -243,22 +218,16 @@ void Parser::operation() {
   } break;
   case functions::Function::ArgumentKind::Shell:
     command->argument = functions::Function::ShellArg(std::string(peek_str()));
-    tokens->push_back(
-      {.start = i,
-       .end = i + peek_str().size(),
-       .type = io::Token::Shell}
-    );
+    token(io::Token::Shell);
     advance(peek_str().size());
+    end_token();
     break;
   }
   if (!suffix) {
     suffix = peek();
-    tokens->push_back(
-      {.start = i,
-       .end = i + (uint64_t)1,
-       .type = io::Token::Suffix}
-    );
+    token(io::Token::Suffix);
     advance();
+    end_token();
   }
   if (suffix) {
     auto &s = bed.suffixes[suffix - 'a'];

src/internal/parser/parser.cc

@@ -2,6 +2,19 @@
 #include "bed.h"
 
 namespace bed::internal::parser {
+void Parser::token(io::Token::Kind k) {
+  end_token();
+  tokens->push_back({.start = i, .end = 0, .type = k});
+}
+
+void Parser::end_token() {
+  if (tokens->empty())
+    return;
+  auto &b = tokens->back();
+  if (!b.end)
+    b.end = i;
+}
+
 char Parser::peek(uint16_t o) {
   return i + o < cmd.size() ? cmd[i + o] : '\0';
 }
@@ -15,18 +28,16 @@ void Parser::advance(uint16_t c) {
 }
 
 void Parser::skip_ws() {
+  end_token();
   while (peek() == ' ' || peek() == '\t')
     advance();
 }
 
 void Parser::parse() {
+  try {
     skip_ws();
     if (peek() == '@') {
-    tokens->push_back(
-      {.start = 0,
-       .end = 1,
-       .type = io::Token::TempCurrent}
-    );
+      token(io::Token::TempCurrent);
       advance();
       command->temp_address = true;
     } else {
@@ -36,9 +47,18 @@ void Parser::parse() {
     addresses(command->addresses);
     operation();
     skip_ws();
-  if (peek() != '\0')
+    if (peek() != '\0') {
+      token(io::Token::Error);
       throw ed_error("Malformed command");
     }
+    advance(cmd.size() - i);
+    end_token();
+  } catch (const ed_error &e) {
+    advance(cmd.size() - i);
+    end_token();
+    throw;
+  }
+}
 
 Parser::Parser(
   std::string_view cmd, BEd &bed, Command *command,

src/internal/syntax/miniparser.cc

@@ -0,0 +1,120 @@
+#include "internal/syntax/miniparser.h"
+
+namespace bed::internal::syntax {
+MiniParser::MiniParser(Language &lang, vase::Shard *vase, void *initial_state)
+    : lang(lang),
+      start_state(initial_state ? lang.copy(initial_state) : lang.none_state()) {
+  vase::Iterator it(vase, 0, Direction::Forward);
+  void *state = lang.copy(start_state);
+  std::vector<io::Token> tokens;
+  std::vector<ParseEvent> events;
+  const uint64_t count = vase ? vase->lines + 1 : 0;
+  lines.reserve(count);
+  for (uint64_t i = 0; i < count; ++i) {
+    it.next();
+    tokens.clear();
+    events.clear();
+    lang.parse(&state, it.line, i == 0, &tokens, &events);
+    lines.emplace_back(lang.copy(state), std::move(tokens));
+  }
+  lang.destroy(state);
+}
+
+MiniParser::~MiniParser() {
+  if (start_state)
+    lang.destroy(start_state);
+  for (auto &[state, tokens] : lines)
+    if (state)
+      lang.destroy(state);
+}
+
+void MiniParser::dirty(vase::Shard *vase, uint64_t start, uint64_t count) {
+  vase::Iterator it(vase, start, Direction::Forward);
+  void *state = start ? lang.copy(lines[start - 1].first)
+                      : lang.copy(start_state);
+  std::vector<ParseEvent> events;
+  uint64_t i = start;
+  for (; i < start + count; i++) {
+    it.next();
+    auto &line = lines[i];
+    line.second.clear();
+    events.clear();
+    lang.parse(&state, it.line, i == 0, &line.second, &events);
+    lang.destroy(line.first);
+    line.first = lang.copy(state);
+  }
+  while (it.next()) {
+    auto &line = lines[i++];
+    line.second.clear();
+    events.clear();
+    lang.parse(&state, it.line, false, &line.second, &events);
+    if (lang.equal(line.first, state))
+      break;
+    lang.destroy(line.first);
+    line.first = lang.copy(state);
+  }
+  lang.destroy(state);
+}
+
+void MiniParser::insert(vase::Shard *vase, uint64_t start, uint64_t count) {
+  vase::Iterator it(vase, start, Direction::Forward);
+  void *state = start ? lang.copy(lines[start - 1].first)
+                      : lang.copy(start_state);
+  std::vector<ParseEvent> events;
+  std::vector<std::pair<void *, std::vector<io::Token>>> lines_new;
+  std::vector<io::Token> tokens;
+  lines_new.reserve(count);
+  for (uint64_t i = 0; i < count; ++i) {
+    it.next();
+    tokens.clear();
+    events.clear();
+    lang.parse(&state, it.line, start + i == 0, &tokens, &events);
+    lines_new.emplace_back(lang.copy(state), std::move(tokens));
+  }
+  uint64_t i = start;
+  while (it.next()) {
+    auto &line = lines[i++];
+    line.second.clear();
+    events.clear();
+    lang.parse(&state, it.line, i == 0, &line.second, &events);
+    if (lang.equal(line.first, state))
+      break;
+    lang.destroy(line.first);
+    line.first = lang.copy(state);
+  }
+  lines.insert(
+    lines.begin() + start,
+    std::make_move_iterator(lines_new.begin()),
+    std::make_move_iterator(lines_new.end())
+  );
+  lang.destroy(state);
+}
+
+void MiniParser::erase(vase::Shard *vase, uint64_t start, uint64_t count) {
+  if (count == 0)
+    return;
+  void *state = start ? lang.copy(lines[start - 1].first)
+                      : lang.copy(start_state);
+  std::vector<ParseEvent> events;
+  for (uint64_t i = start; i < start + count; ++i)
+    if (lines[i].first)
+      lang.destroy(lines[i].first);
+  lines.erase(
+    lines.begin() + start,
+    lines.begin() + start + count
+  );
+  vase::Iterator it(vase, start, Direction::Forward);
+  uint64_t i = start;
+  while (i < lines.size() && it.next()) {
+    auto &line = lines[i];
+    line.second.clear();
+    events.clear();
+    lang.parse(&state, it.line, i++ == 0, &line.second, &events);
+    if (lang.equal(line.first, state))
+      break;
+    lang.destroy(line.first);
+    line.first = lang.copy(state);
+  }
+  lang.destroy(state);
+}
+} // namespace bed::internal::syntax

src/internal/syntax/ruby/parse.cc

@@ -1030,6 +1030,7 @@ bool handle_syntax(RubyParser &p, std::vector<io::Token> *tokens, std::vector<Pa
             || p.peek(j) == '^'
             || p.peek(j) == '<'
             || p.peek(j) == '>'
+            || p.peek(j) == '#'
           ) {
             return false;
           }

src/internal/theme/theme.cc

@@ -63,11 +63,6 @@ Theme Theme::default_theme() {
     .bg = 0x000000,
     .flags = io::Highlight::None,
   };
-  theme.hl[io::Token::Any] = {
-    .fg = GREY,
-    .bg = 0x000000,
-    .flags = io::Highlight::None,
-  };
   theme.hl[io::Token::Shell] = {
     .fg = BRIGHT_GREEN,
     .bg = 0x000000,

src/internal/ui/command/command.cc

@@ -3,66 +3,6 @@
 #include "internal/parser/parser.h"
 
 namespace bed::internal::ui {
-/*template <typename F>
-static void for_each_cluster(std::string_view s, F &&f) {
-  unicode_width_state_t state;
-  unicode_width_init(&state);
-  size_t i = 0;
-  while (i < s.size()) {
-    unsigned char c = static_cast<unsigned char>(s[i]);
-    size_t bytes = 1;
-    int width = 0;
-    if (c < 128) {
-      width = unicode_width_process(&state, c);
-    } else {
-      uint_least32_t cp;
-      size_t decoded = grapheme_decode_utf8(s.data() + i, s.size() - i, &cp);
-      bytes = decoded > 0 ? decoded : 1;
-      width = unicode_width_process(&state, cp);
-    }
-    if (width < 0)
-      width = 0;
-    f(i, bytes, width);
-    i += bytes;
-  }
-}
-
-static int display_width(std::string_view s) {
-  int w = 0;
-  for_each_cluster(s, [&](size_t, size_t, int cw) { w += cw; });
-  return w;
-}
-
-static uint16_t count_clusters(std::string_view s) {
-  uint16_t n = 0;
-  for_each_cluster(s, [&](size_t, size_t, int) { ++n; });
-  return n;
-}
-
-static std::vector<uint16_t> wrap_offsets(std::string_view line, uint16_t avail) {
-  std::vector<uint16_t> offsets{0};
-  int col = 0;
-  for_each_cluster(line, [&](uint16_t i, uint16_t, int w) {
-    if (col + w > avail && col > 0) {
-      offsets.push_back(i);
-      col = 0;
-    }
-    col += w;
-  });
-  return offsets;
-}
-
-// The word under/before `byte_pos`, split on plain ASCII spaces. Used to
-// pick what prefix to hand the suggestion trie.
-// TODO: change to use libgrapheme word break here.
-static std::string current_word(const std::string &line, size_t byte_pos) {
-  size_t start = (byte_pos == 0) ? std::string::npos : line.rfind(' ', byte_pos - 1);
-  start = (start == std::string::npos) ? 0 : start + 1;
-  if (byte_pos < start)
-    byte_pos = start;
-  return line.substr(start, byte_pos - start);
-}*/
-
 CommandIO::CommandIO(BEd &bed) : bed(bed) {
   if (bed.prompt_mode)
     prompt = bed.prompt(bed);

src/internal/ui/text_mode/text_mode.cc

@@ -1,9 +1,132 @@
 #include "internal/ui/text_mode.h"
 #include "bed.h"
 
-namespace bed::internal::ui {
-TextMode::TextMode(BEd &bed) : bed(bed) {
-  cursor = 0;
+namespace bed::internal::ui::text_mode {
+template <typename F>
+static void for_each_cluster(std::string_view s, F &&f) {
+  size_t cluster_start = 0;
+  while (cluster_start < s.size()) {
+    size_t cluster_len =
+      grapheme_next_character_break_utf8(
+        s.data() + cluster_start,
+        s.size() - cluster_start
+      );
+    if (cluster_len == 0)
+      break;
+    size_t cluster_end = cluster_start + cluster_len;
+    unicode_width_state_t state;
+    unicode_width_init(&state);
+    size_t i = cluster_start;
+    int width = 0;
+    while (i < cluster_end) {
+      uint_least32_t cp;
+      size_t decoded =
+        grapheme_decode_utf8(s.data() + i, cluster_end - i, &cp);
+      if (decoded == 0)
+        decoded = 1;
+      int w = unicode_width_process(&state, cp);
+      if (w > width)
+        width = w;
+      i += decoded;
+    }
+    if (width < 0)
+      width = 0;
+    if (!f(cluster_start, cluster_len, width))
+      return;
+    cluster_start = cluster_end;
+  }
+}
+
+static size_t previous_cluster(std::string_view line, size_t col) {
+  size_t previous = 0;
+  for_each_cluster(line, [&](size_t start, size_t len, int) {
+    if (start >= col)
+      return false;
+    previous = start;
+    return start + len < col;
+  });
+  return previous;
+}
+
+static size_t next_cluster(std::string_view line, size_t col) {
+  size_t next = line.size();
+  for_each_cluster(line, [&](size_t start, size_t len, int) {
+    if (start >= col) {
+      next = start + len;
+      return false;
+    }
+    return true;
+  });
+  return next;
+}
+
+static size_t visual_column(std::string_view line, size_t col) {
+  size_t width = 0;
+  for_each_cluster(line, [&](size_t start, size_t, int cluster_width) {
+    if (start >= col)
+      return false;
+    width += cluster_width;
+    return true;
+  });
+  return width;
+}
+
+static size_t byte_column(std::string_view line, size_t target_width) {
+  size_t width = 0;
+  size_t col = 0;
+  for_each_cluster(line, [&](size_t start, size_t len, int cluster_width) {
+    if (width + cluster_width > target_width)
+      return false;
+    width += cluster_width;
+    col = start + len;
+    if (width == target_width)
+      return false;
+    return true;
+  });
+  return col;
+}
+
+static std::vector<std::pair<size_t, size_t>> wrap_line(std::string_view line, size_t avail) {
+  std::vector<std::pair<size_t, size_t>> result;
+  if (avail == 0) {
+    result.push_back({0, line.size()});
+    return result;
+  }
+  size_t begin = 0;
+  size_t end = 0;
+  int col = 0;
+  for_each_cluster(line, [&](size_t i, size_t len, int width) {
+    if (col > 0 && col + width > int(avail)) {
+      result.push_back({begin, i});
+      begin = i;
+      col = 0;
+    }
+    col += width;
+    end = i + len;
+    return true;
+  });
+  if (begin < line.size() || result.empty())
+    result.push_back({begin, end});
+  return result;
+}
+
+void TextMode::layout_lines() {
+  vase::Iterator it(vase, 0, Direction::Forward);
+  lines.clear();
+  while (it.next()) {
+    auto wrapped = wrap_line(it.line, term_width);
+    lines.push_back({});
+    for (auto [begin, end] : wrapped)
+      lines.back().push_back({begin, end - begin});
+  }
+}
+
+TextMode::TextMode(
+  BEd &bed, vase::Shard *vase, syntax::Language *lang, void *state
+) : vase(vase), bed(bed) {
+  if (lang)
+    parser.emplace(*lang, vase, state);
+  cursor = vase::eof_point(vase);
 }
 
 std::pair<vase::Shard *, bool> TextMode::run() {
@@ -13,31 +136,32 @@ std::pair<vase::Shard *, bool> TextMode::run() {
 }
 
 std::pair<vase::Shard *, bool> TextMode::run_pipe() {
-  cmd.clear();
+  vase::Shard::release(vase);
+  vase = nullptr;
   while (true) {
     auto [str, eof] = bed.io.read_pipe();
     if (str == "." || eof)
       break;
-    cmd += str + "\n";
+    vase = vase::insert(&bed.append, vase, &cursor, str.data(), str.length());
+    vase = vase::insert(&bed.append, vase, &cursor, '\n');
   }
-  return {vase::Shard::from_string(cmd.data(), cmd.length(), true), false};
+  return {vase, false};
 }
 
 std::pair<vase::Shard *, bool> TextMode::run_terminal() {
   auto [row, col] = bed.io.cursor_position();
   auto [rows, cols] = bed.io.terminal_size();
   if (row > rows)
-    throw fatal_error("Invalid cursor position.", 1);
+    throw ed_error("Invalid cursor position.");
   start = row;
   height = rows - row + 1;
   term_width = cols;
   term_height = rows;
-  cmd.clear();
-  cursor = 0;
   redraw();
   bool running = true;
 
   while (running) {
+    redraw();
     io::KeyEvent res = bed.io.read_key();
     switch (res.type) {
     case io::KeyEvent::KeyType::EOF_:
@@ -52,110 +176,151 @@ std::pair<vase::Shard *, bool> TextMode::run_terminal() {
       case io::KeyEvent::Modifier::ALT:
       case io::KeyEvent::Modifier::CTRL_ALT:
       case io::KeyEvent::Modifier::CTRL:
+        if (res.text[0] == 'c')
+          return {vase, true};
         break;
       case io::KeyEvent::Modifier::NONE:
         if (res.text[0] == '\b' || res.text[0] == 0x7f) {
-          if (cursor > 0) {
-            cmd.erase(--cursor, 1);
+          if (!vase)
+            break;
+          if (cursor.row || cursor.col) {
+            auto last = cursor;
+            if (last.col) {
+              vase::Iterator it(vase, last.row, Direction::Forward);
+              if (!it.next())
+                throw ed_error("Invalid cursor position.");
+              last.col = previous_cluster(it.line, last.col);
+            } else if (last.row) {
+              --last.row;
+              vase::Iterator it(vase, last.row, Direction::Forward);
+              if (!it.next())
+                throw ed_error("Invalid cursor position.");
+              last.col = it.line.size();
+            } else {
+              break;
+            }
+            vase::Range r = {last, cursor};
+            vase = vase::erase(vase, r);
+            if (cursor.row == last.row) {
+              parser->dirty(vase, cursor.row, 1);
+            } else {
+              parser->erase(vase, cursor.row, 1);
+              parser->dirty(vase, last.row, 1);
+            }
+            cursor = last;
           }
         } else if (res.text[0] == '\n') {
-          cmd.insert(cursor++, 1, '\n');
-          grow();
+          if (vase && cursor.row == vase->lines) {
+            vase::Iterator it(vase, vase->lines, Direction::Backward);
+            if (it.next() && it.line == ".") {
+              vase = vase::erase(vase, vase->lines + 1, vase->lines + 1);
+              running = false;
+              break;
+            }
+          }
+          vase = vase::insert(&bed.append, vase, &cursor, '\n');
+          parser->insert(vase, cursor.row - 1, 1);
         } else {
-          cmd.insert(cursor, res.text);
-          cursor += res.text.size();
+          vase = vase::insert(&bed.append, vase, &cursor, res.text.data(), res.text.size());
+          parser->dirty(vase, cursor.row, 1);
         }
         break;
       }
       break;
-    case io::KeyEvent::KeyType::PASTE:
-      cmd.insert(cursor, res.text);
-      cursor += res.text.size();
-      grow();
-      break;
+    case io::KeyEvent::KeyType::PASTE: {
+      auto lines = std::count(res.text.begin(), res.text.end(), '\n');
+      vase = vase::insert(&bed.append, vase, &cursor, res.text.data(), res.text.size());
+      if (lines) {
+        parser->insert(vase, cursor.row - lines, lines);
+        parser->dirty(vase, cursor.row - lines, 1);
+      } else {
+        parser->dirty(vase, cursor.row, 1);
+      }
+    } break;
     case io::KeyEvent::KeyType::SPECIAL:
+      if (!vase)
+        break;
       switch (res.special_key) {
       case io::KeyEvent::SpecialKey::UNKNOWN:
         break;
-      case io::KeyEvent::SpecialKey::RIGHT:
-        if (cursor < cmd.size())
-          ++cursor;
-        break;
-      case io::KeyEvent::SpecialKey::LEFT:
-        if (cursor > 0)
-          --cursor;
-        break;
+      case io::KeyEvent::SpecialKey::RIGHT: {
+        vase::Iterator it(vase, cursor.row, Direction::Forward);
+        if (!it.next())
+          throw ed_error("Invalid cursor position.");
+        cursor.col = next_cluster(it.line, cursor.col);
+      } break;
+      case io::KeyEvent::SpecialKey::LEFT: {
+        vase::Iterator it(vase, cursor.row, Direction::Forward);
+        if (!it.next())
+          throw ed_error("Invalid cursor position.");
+        cursor.col = previous_cluster(it.line, cursor.col);
+      } break;
       case io::KeyEvent::SpecialKey::UP: {
-        size_t line_start =
-          cmd.rfind('\n', cursor == 0 ? 0 : cursor - 1);
-        if (line_start == std::string::npos)
-          line_start = 0;
-        else
-          ++line_start;
-        size_t col = cursor - line_start;
-        if (line_start == 0)
+        if (!cursor.row)
           break;
-        size_t prev_end = line_start - 1;
-        size_t prev_start =
-          cmd.rfind('\n', prev_end == 0 ? 0 : prev_end - 1);
-        if (prev_start == std::string::npos)
-          prev_start = 0;
-        else
-          ++prev_start;
-        size_t prev_len = prev_end - prev_start;
-        cursor = prev_start + std::min(col, prev_len);
-        break;
-      }
+        vase::Iterator current(vase, cursor.row, Direction::Forward);
+        if (!current.next())
+          throw ed_error("Invalid cursor position.");
+        size_t wanted = visual_column(current.line, cursor.col);
+        --cursor.row;
+        vase::Iterator previous(vase, cursor.row, Direction::Forward);
+        if (!previous.next())
+          throw ed_error("Invalid cursor position.");
+        cursor.col = byte_column(previous.line, wanted);
+      } break;
       case io::KeyEvent::SpecialKey::DOWN: {
-        size_t line_start =
-          cmd.rfind('\n', cursor == 0 ? 0 : cursor - 1);
-        if (line_start == std::string::npos)
-          line_start = 0;
-        else
-          ++line_start;
-        size_t col = cursor - line_start;
-        size_t line_end = cmd.find('\n', cursor);
-        if (line_end == std::string::npos)
-          line_end = cmd.size();
-        if (line_end == cmd.size())
+        if (cursor.row + 1 >= vase->lines)
           break;
-        size_t next_start = line_end + 1;
-        size_t next_end = cmd.find('\n', next_start);
-        if (next_end == std::string::npos)
-          next_end = cmd.size();
-        size_t next_len = next_end - next_start;
-        cursor = next_start + std::min(col, next_len);
-        break;
-      }
+        vase::Iterator current(vase, cursor.row, Direction::Forward);
+        if (!current.next())
+          throw ed_error("Invalid cursor position.");
+        size_t wanted = visual_column(current.line, cursor.col);
+        ++cursor.row;
+        vase::Iterator previous(vase, cursor.row, Direction::Forward);
+        if (!previous.next())
+          throw ed_error("Invalid cursor position.");
+        cursor.col = byte_column(previous.line, wanted);
+      } break;
       case io::KeyEvent::SpecialKey::DELETE:
-        if (cursor < cmd.size())
-          cmd.erase(cursor, 1);
+        auto next = cursor;
+        vase::Iterator it(vase, cursor.row, Direction::Forward);
+        if (!it.next())
+          break;
+        if (cursor.col < it.line.size()) {
+          vase::Iterator it(vase, next.row, Direction::Forward);
+          if (!it.next())
+            throw ed_error("Invalid cursor position.");
+          next.col = next_cluster(it.line, cursor.col);
+        } else if (cursor.row + 1 < vase->lines) {
+          ++next.row;
+          next.col = 0;
+        } else {
           break;
         }
+        vase::Range r = {cursor, next};
+        vase = vase::erase(vase, r);
+        if (cursor.row != next.row)
+          parser->erase(vase, cursor.row + 1, 1);
+        parser->dirty(vase, cursor.row, 1);
+      }
       break;
     }
-    redraw();
-    if (cmd.size() >= 3 && cmd.compare(cmd.size() - 3, 3, "\n.\n") == 0) {
-      cmd.erase(cmd.size() - 3);
-      cursor = cmd.size();
-      running = false;
-    }
-    if (cmd.size() == 2 && cmd.compare(0, 2, ".\n") == 0) {
-      cmd.clear();
-      cursor = 0;
-      running = false;
-    }
   }
 
-  size_t total_lines = cmd.size() ? 1 + std::count(cmd.begin(), cmd.end(), '\n') : 0;
-  uint16_t last_row = start + total_lines;
+  layout_lines();
+  size_t required_height = 0;
+  for (const auto &elem : lines)
+    required_height += elem.size();
+  uint16_t last_row = start + required_height;
   bed.io.move_cursor(last_row, 1);
-  bed.io.write("\n", 1);
-  return {vase::Shard::from_string(cmd.data(), cmd.length(), true), false};
+  bed.io.write("\n");
+  return {vase, false};
 }
 
 void TextMode::grow() {
-  size_t required_height = 1 + std::count(cmd.begin(), cmd.end(), '\n');
+  size_t required_height = 0;
+  for (const auto &elem : lines)
+    required_height += elem.size();
   auto [rows, cols] = bed.io.terminal_size();
   term_height = rows;
   term_width = cols;
@@ -166,46 +331,85 @@ void TextMode::grow() {
     return;
   bed.io.move_cursor(rows, 1);
   for (long i = 0; i < overflow; ++i)
-    bed.io.write("\n", 1);
+    bed.io.write("\n");
   start -= overflow;
   if (start < 1)
     start = 1;
 }
 
 void TextMode::redraw() {
-  auto [rows, cols] = bed.io.terminal_size();
-  term_height = rows;
-  term_width = cols;
+  layout_lines();
+  grow();
+  bed.io.write("\x1b[?25l", 6);
   for (uint16_t i = 0; i < height; ++i) {
     bed.io.move_cursor(start + i, 1);
     bed.io.write("\x1b[2K", 4);
   }
-  size_t line = 0;
-  size_t line_start = 0;
-  for (size_t i = 0; i < cursor; ++i) {
-    if (cmd[i] == '\n') {
-      ++line;
-      line_start = i + 1;
-    }
-  }
-  size_t col = cursor - line_start;
-  size_t pos = 0;
   uint16_t screen_line = start;
-  while (pos <= cmd.size()) {
-    size_t end = cmd.find('\n', pos);
-    if (end == std::string::npos)
-      end = cmd.size();
-    if (screen_line < start + height) {
-      size_t len = std::min(end - pos, size_t(term_width));
-      bed.io.move_cursor(screen_line, 1);
-      bed.io.write(cmd.substr(pos, len));
-    }
-    if (end == cmd.size())
+  uint64_t line = 0;
+  size_t cursor_screen_row = start;
+  size_t cursor_screen_col = 0;
+  vase::Iterator it(vase, line, Direction::Forward);
+  while (it.next()) {
+    if (screen_line >= start + height)
       break;
-    pos = end + 1;
+    std::string_view l(it.line);
+    const std::vector<io::Token> *tokens = nullptr;
+    if (parser && parser->lines.size() > line)
+      tokens = &parser->lines[line].second;
+    size_t token_index = 0;
+    for (auto &row : lines[line]) {
+      const size_t row_start = row.start;
+      const size_t row_end = row.start + row.length;
+      bed.io.move_cursor(screen_line, 1);
+      if (tokens) {
+        while (token_index < tokens->size() && (*tokens)[token_index].end <= row_start)
+          ++token_index;
+        size_t pos = row_start;
+        for (size_t i = token_index; i < tokens->size(); ++i) {
+          const auto &token = (*tokens)[i];
+          if (token.start >= row_end)
+            break;
+          const size_t begin = std::max<size_t>(
+            token.start,
+            row_start
+          );
+          const size_t end = std::min<size_t>(
+            token.end,
+            row_end
+          );
+          if (begin > pos)
+            bed.io.write(l.data() + pos, begin - pos);
+          if (begin < end) {
+            bed.io.apply(token.type);
+            bed.io.write(l.data() + begin, end - begin);
+            bed.io.reset();
+            pos = end;
+          }
+        }
+        if (pos < row_end)
+          bed.io.write(l.data() + pos, row_end - pos);
+        bed.io.reset();
+      } else {
+        bed.io.write(l.substr(row_start, row.length));
+      }
+      if (line == cursor.row && cursor.col >= row_start && cursor.col <= row_end) {
+        cursor_screen_row = screen_line;
+        cursor_screen_col = 0;
+        for_each_cluster(
+          l.substr(row_start, cursor.col - row_start),
+          [&](size_t, size_t, int width) {
+            cursor_screen_col += width;
+            return true;
+          }
+        );
+      }
       ++screen_line;
     }
-  size_t vis_col = std::min(col, size_t(term_width - 1));
-  bed.io.move_cursor(start + line, vis_col + 1);
+    ++line;
   }
-} // namespace bed::internal::ui
+  cursor_screen_col = std::min(cursor_screen_col, size_t(term_width - 1));
+  bed.io.move_cursor(cursor_screen_row, cursor_screen_col + 1);
+  bed.io.write("\x1b[?25h", 6);
+}
+} // namespace bed::internal::ui::text_mode

src/internal/vase/vase.cc

@@ -74,14 +74,7 @@ void _insert(AppendStorage *ap, Shard **root, Point *point, const char *data, ui
     ++lines;
     last_line = ++data;
   }
-  uint64_t col = 0;
-  uint64_t remaining = end - last_line;
-  while (remaining) {
-    uint64_t n = grapheme_next_character_break_utf8(last_line, remaining);
-    last_line += n;
-    remaining -= n;
-    ++col;
-  }
+  uint64_t col = end - last_line;
   if (lines) {
     point->row += lines;
     point->col = col;
@@ -122,6 +115,22 @@ Shard *replace(AppendStorage *ap, Shard *root, Range range, const char *data, ui
   return insert(ap, root, &range.start, data, len);
 }
 
+Point eof_point(Shard *root) {
+  if (!root)
+    return {0, 0};
+  Point result{
+    .row = root->lines,
+    .col = 0
+  };
+  PetalIterator it(root, Direction::Forward);
+  it.seek_line(root->lines);
+  const char *data;
+  uint64_t len;
+  while (it.next(&data, &len))
+    result.col += len;
+  return result;
+}
+
 uint64_t offset_of(Shard *root, Point point) {
   return offset_of(root, point.row) + point.col;
 }