Setup routing.

include/cli.h

@@ -3,7 +3,20 @@
 #include "pch.h"
 
 namespace crib::cli {
+struct Command {
+  void (*run)(std::vector<std::string>);
+  std::string (*summary)();
+  void (*help)();
+};
+
+struct cli_error : std::runtime_error {
+  int exit_code;
+  cli_error(std::string msg, int code)
+      : std::runtime_error(std::move(msg)), exit_code(code) {}
+};
+
 extern bool use_colors;
 void help();
+int execute(const std::string &name, const Command &cmd, int argc, char *argv[]);
 int run(int argc, char *argv[]);
 } // namespace crib::cli

include/commands/ed/ed.h

@@ -6,5 +6,5 @@
 namespace crib::commands::ed {
 std::string summary();
 void help();
-void run(int argc, char *argv[]);
+void run(std::vector<std::string>);
 } // namespace crib::commands::ed

include/internal/vase/iterators/line.h

@@ -19,4 +19,56 @@ struct LineIterator {
   bool next(std::string *line);
   uint64_t byte_offset();
 };
+
+struct Iterator {
+  Shard *root;
+  std::string line;
+
+  Iterator(Shard *root, uint64_t line_num)
+      : root(root), it(root, line_num, Direction::Forward) {
+    Shard::retain(root);
+  }
+
+  ~Iterator() {
+    Shard::release(root);
+  }
+
+  Iterator(const Iterator &other)
+      : root(other.root), it(other.it) {
+    Shard::retain(root);
+  }
+
+  Iterator &operator=(const Iterator &other) {
+    if (this != &other) {
+      Shard::retain(other.root);
+      Shard::release(root);
+      root = other.root;
+      it = other.it;
+    }
+    return *this;
+  }
+
+  Iterator(Iterator &&other) noexcept
+      : root(other.root), it(std::move(other.it)) {
+    other.root = nullptr;
+  }
+
+  Iterator &operator=(Iterator &&other) noexcept {
+    if (this != &other) {
+      Shard::release(root);
+      root = other.root;
+      it = std::move(other.it);
+      other.root = nullptr;
+    }
+    return *this;
+  }
+
+  std::string &next() {
+    it.next(&line);
+    return line;
+  }
+
+private:
+  LineIterator it;
+};
 } // namespace crib::internal::vase

include/internal/vase/vase.h

@@ -53,9 +53,7 @@ struct Vase {
   std::string to_string();
   std::string to_string(Range range);
 
-  Point resolve_column(uint64_t line, uint64_t column);
-
-  LineIterator iterate(uint64_t line);
+  Iterator iterate(uint64_t line);
 
   void insert(Point *point, char key);
   void insert(Point *point, const char *data, uint64_t len);