diff --git a/src/bed/bed.cc b/src/bed/bed.cc
new file mode 100644
index 0000000..b247d01
--- /dev/null
+++ b/src/bed/bed.cc
@@ -0,0 +1,73 @@
+#include "bed.h"
+#include "internal/parser/parser.h"
+
+namespace bed {
+BEd::BEd(std::vector<std::string> args)
+    : theme(internal::theme::Theme::default_theme()), io(*this) {
+  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++;
+      if (i >= args.size())
+        throw fatal_error("Prompt not specified!", 1);
+      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") {
+      print_help();
+      throw fatal_error("", 0);
+    } else {
+      if (file.size())
+        throw fatal_error("Invalid arguments given.", 1);
+      file = args[i];
+    }
+  }
+  if (prompt_ != "")
+    prompt = [p = std::move(prompt_)](BEd &) { return p; };
+  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);
+  languages["ruby"] = new internal::syntax::Language(internal::syntax::ruby::lang_ruby());
+  buffers["clip"] = new internal::buffer::ClipBuffer("clip");
+  current() = {"default", 0};
+  try {
+    if (file != "")
+      handle(":default:E " + file, false);
+  } catch (ed_error &e) {
+    io.write_line("?");
+    if (help_mode)
+      io.write_line(e.what());
+    last_help = e.what();
+  }
+}
+
+BEd::~BEd() {
+  for (auto &[_, buffer] : buffers)
+    delete buffer;
+  for (auto &[_, lang] : languages)
+    delete lang;
+}
+
+void BEd::print_help() {
+  io.write("BEd - A line editor.\n");
+}
+} // namespace bed
diff --git a/src/bed/handle.cc b/src/bed/handle.cc
new file mode 100644
index 0000000..d4652c3
--- /dev/null
+++ b/src/bed/handle.cc
@@ -0,0 +1,132 @@
+#include "bed.h"
+#include "internal/parser/parser.h"
+
+namespace bed {
+void BEd::run() {
+  while (true) {
+    internal::ui::CommandIO command(*this);
+    auto [cmd, eof] = command.run();
+    try {
+      handle(cmd, eof);
+    } catch (ed_error &e) {
+      io.apply(internal::io::Token::Warning);
+      io.write_line("?");
+      if (help_mode)
+        io.write_line(e.what());
+      io.reset();
+      last_help = e.what();
+    }
+  }
+}
+
+void BEd::handle(std::string_view cmd, bool eof) {
+  if (eof && cmd.empty()) {
+    eof_op.handle(*this, "", nullptr, std::monostate(), nullptr);
+    return;
+  }
+  internal::parser::Command c = internal::parser::Parser::get_command(cmd, *this);
+  if (c.temp_address) {
+    marks.get(251) = marks.get(250);
+    prev_2 = prev_1;
+    temporary_current = true;
+  }
+  internal::buffer::Address address;
+  switch (c.function->address_kind) {
+  case internal::functions::Function::AddressKind::None: {
+    auto a = internal::parser::AddressPromise::get_line(*this, c.addresses);
+    if (!a.has_value()) {
+      auto vec = internal::parser::Parser::get_addresses(c.function->default_address, *this);
+      a = internal::parser::AddressPromise::get_line(*this, vec);
+      if (!a.has_value())
+        a = current();
+    }
+    address = a->buffername;
+  } break;
+  case internal::functions::Function::AddressKind::Line: {
+    auto a = internal::parser::AddressPromise::get_line(*this, c.addresses);
+    if (!a.has_value()) {
+      auto vec = internal::parser::Parser::get_addresses(c.function->default_address, *this);
+      a = internal::parser::AddressPromise::get_line(*this, vec);
+      if (!a.has_value())
+        a = current();
+    }
+    address = *a;
+  } break;
+  case internal::functions::Function::AddressKind::Range: {
+    auto a = internal::parser::AddressPromise::get_range(*this, c.addresses);
+    if (!a.has_value()) {
+      auto vec = internal::parser::Parser::get_addresses(c.function->default_address, *this);
+      a = internal::parser::AddressPromise::get_range(*this, vec);
+      if (!a.has_value())
+        a = internal::buffer::Range(current(), current());
+    }
+    address = *a;
+  } break;
+  }
+  if (std::holds_alternative<internal::buffer::Line>(c.argument)) {
+    if (c.argument_addresses.empty())
+      throw ed_error("Function needs address argument.");
+    auto a = internal::parser::AddressPromise::get_line(*this, c.argument_addresses);
+    if (a.has_value())
+      c.argument = *a;
+    else
+      c.argument = current();
+  } else if (std::holds_alternative<internal::buffer::Range>(c.argument)) {
+    if (c.argument_addresses.empty())
+      throw ed_error("Function needs address argument.");
+    auto a = internal::parser::AddressPromise::get_range(*this, c.argument_addresses);
+    if (a.has_value())
+      c.argument = *a;
+    else
+      c.argument = internal::buffer::Range(current(), current());
+  }
+  if (!c.function->accept_zero) {
+    if (std::holds_alternative<internal::buffer::Line>(address)) {
+      if (std::get<internal::buffer::Line>(address).number == 0)
+        throw ed_error("Line number can't be zero.");
+    } else if (std::holds_alternative<internal::buffer::Range>(address)) {
+      auto r = std::get<internal::buffer::Range>(address);
+      if (r.start == 0 || r.end == 0)
+        throw ed_error("Line number can't be zero.");
+    }
+  }
+  internal::vase::Shard *text = nullptr;
+  if (c.function->input_mode == internal::functions::Function::InputMode::Text) {
+    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 {
+      if (a) {
+        auto p = internal::syntax::make_parser(a, a->lines + 1, lang);
+        auto cancel_buf = new internal::buffer::ReadonlyBuffer("cancel", a, p);
+        internal::syntax::release(p);
+        buffers["cancel"] = cancel_buf;
+        cancel_buf->useless = false;
+        internal::vase::Shard::release(a);
+      }
+      throw ed_error("Operation cancelled.");
+    }
+  }
+  if (c.function->handle)
+    c.function->handle(*this, address, text, c.argument, nullptr);
+  if (c.suffix)
+    c.suffix->handle(*this);
+  if (c.temp_address)
+    temporary_current = false;
+  for (auto it = buffers.begin(); it != buffers.end();) {
+    internal::buffer::Buffer *buf = it->second;
+    if (buf->waste()) {
+      delete buf;
+      it = buffers.erase(it);
+    } else {
+      ++it;
+    }
+  }
+}
+} // namespace bed
diff --git a/src/bed/run.cc b/src/bed/run.cc
index b5caf0a..b423962 100644
--- a/src/bed/run.cc
+++ b/src/bed/run.cc
@@ -2,75 +2,6 @@
 #include "internal/parser/parser.h"
 
 namespace bed {
-BEd::BEd(std::vector<std::string> args)
-    : theme(internal::theme::Theme::default_theme()), io(*this) {
-  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++;
-      if (i >= args.size())
-        throw fatal_error("Prompt not specified!", 1);
-      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") {
-      print_help();
-      throw fatal_error("", 0);
-    } else {
-      if (file.size())
-        throw fatal_error("Invalid arguments given.", 1);
-      file = args[i];
-    }
-  }
-  if (prompt_ != "")
-    prompt = [p = std::move(prompt_)](BEd &) { return p; };
-  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);
-  languages["ruby"] = new internal::syntax::Language(internal::syntax::ruby::lang_ruby());
-  buffers["clip"] = new internal::buffer::ClipBuffer("clip");
-  current() = {"default", 0};
-  try {
-    if (file != "")
-      handle(":default:E " + file, false);
-  } catch (ed_error &e) {
-    io.write_line("?");
-    if (help_mode)
-      io.write_line(e.what());
-    last_help = e.what();
-  }
-}
-
-BEd::~BEd() {
-  for (auto &[_, buffer] : buffers)
-    delete buffer;
-  for (auto &[_, lang] : languages)
-    delete lang;
-}
-
-void BEd::print_help() {
-  io.write("BEd - A line editor.\n");
-}
-
 void BEd::run() {
   while (true) {
     internal::ui::CommandIO command(*this);
@@ -88,117 +19,6 @@ void BEd::run() {
   }
 }
 
-void BEd::handle(std::string_view cmd, bool eof) {
-  if (eof && cmd.empty()) {
-    eof_op.handle(*this, "", nullptr, std::monostate(), nullptr);
-    return;
-  }
-  internal::parser::Command c = internal::parser::Parser::get_command(cmd, *this);
-  if (c.temp_address) {
-    marks.get(251) = marks.get(250);
-    prev_2 = prev_1;
-    temporary_current = true;
-  }
-  internal::buffer::Address address;
-  switch (c.function->address_kind) {
-  case internal::functions::Function::AddressKind::None: {
-    auto a = internal::parser::AddressPromise::get_line(*this, c.addresses);
-    if (!a.has_value()) {
-      auto vec = internal::parser::Parser::get_addresses(c.function->default_address, *this);
-      a = internal::parser::AddressPromise::get_line(*this, vec);
-      if (!a.has_value())
-        a = current();
-    }
-    address = a->buffername;
-  } break;
-  case internal::functions::Function::AddressKind::Line: {
-    auto a = internal::parser::AddressPromise::get_line(*this, c.addresses);
-    if (!a.has_value()) {
-      auto vec = internal::parser::Parser::get_addresses(c.function->default_address, *this);
-      a = internal::parser::AddressPromise::get_line(*this, vec);
-      if (!a.has_value())
-        a = current();
-    }
-    address = *a;
-  } break;
-  case internal::functions::Function::AddressKind::Range: {
-    auto a = internal::parser::AddressPromise::get_range(*this, c.addresses);
-    if (!a.has_value()) {
-      auto vec = internal::parser::Parser::get_addresses(c.function->default_address, *this);
-      a = internal::parser::AddressPromise::get_range(*this, vec);
-      if (!a.has_value())
-        a = internal::buffer::Range(current(), current());
-    }
-    address = *a;
-  } break;
-  }
-  if (std::holds_alternative<internal::buffer::Line>(c.argument)) {
-    if (c.argument_addresses.empty())
-      throw ed_error("Function needs address argument.");
-    auto a = internal::parser::AddressPromise::get_line(*this, c.argument_addresses);
-    if (a.has_value())
-      c.argument = *a;
-    else
-      c.argument = current();
-  } else if (std::holds_alternative<internal::buffer::Range>(c.argument)) {
-    if (c.argument_addresses.empty())
-      throw ed_error("Function needs address argument.");
-    auto a = internal::parser::AddressPromise::get_range(*this, c.argument_addresses);
-    if (a.has_value())
-      c.argument = *a;
-    else
-      c.argument = internal::buffer::Range(current(), current());
-  }
-  if (!c.function->accept_zero) {
-    if (std::holds_alternative<internal::buffer::Line>(address)) {
-      if (std::get<internal::buffer::Line>(address).number == 0)
-        throw ed_error("Line number can't be zero.");
-    } else if (std::holds_alternative<internal::buffer::Range>(address)) {
-      auto r = std::get<internal::buffer::Range>(address);
-      if (r.start == 0 || r.end == 0)
-        throw ed_error("Line number can't be zero.");
-    }
-  }
-  internal::vase::Shard *text = nullptr;
-  if (c.function->input_mode == internal::functions::Function::InputMode::Text) {
-    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 {
-      if (a) {
-        auto p = internal::syntax::make_parser(a, a->lines + 1, lang);
-        auto cancel_buf = new internal::buffer::ReadonlyBuffer("cancel", a, p);
-        internal::syntax::release(p);
-        buffers["cancel"] = cancel_buf;
-        cancel_buf->useless = false;
-        internal::vase::Shard::release(a);
-      }
-      throw ed_error("Operation cancelled.");
-    }
-  }
-  if (c.function->handle)
-    c.function->handle(*this, address, text, c.argument, nullptr);
-  if (c.suffix)
-    c.suffix->handle(*this);
-  if (c.temp_address)
-    temporary_current = false;
-  for (auto it = buffers.begin(); it != buffers.end();) {
-    internal::buffer::Buffer *buf = it->second;
-    if (buf->waste()) {
-      delete buf;
-      it = buffers.erase(it);
-    } else {
-      ++it;
-    }
-  }
-}
-
 internal::buffer::Buffer &BEd::buffer(const std::string &name) {
   if (name.empty())
     throw ed_error("Can't have empty buffer name");
diff --git a/src/internal/ui/text_mode/text_mode.cc b/src/internal/ui/text_mode/text_mode.cc
index 84c4b98..f93be6a 100644
--- a/src/internal/ui/text_mode/text_mode.cc
+++ b/src/internal/ui/text_mode/text_mode.cc
@@ -2,6 +2,8 @@
 #include "bed.h"
 
 namespace bed::internal::ui::text_mode {
+// TODO: make this into a proper layout engine, in order to avoid so many expensive calculations repeatedly.
+
 template <typename F>
 static void for_each_cluster(std::string_view s, F &&f) {
   size_t cluster_start = 0;