Implement Pathname#find in builtin Pathname

Copy the traversal logic from Find.find (lib/find.rb) into
pathname_builtin.rb to remove the runtime dependency on the find
library. The implementation preserves the same error handling,
encoding, traversal order, and catch(:prune) support.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hsbt

lib/pathname.rb

@@ -9,35 +9,6 @@
 #
 # For documentation, see class Pathname.
 #
-class Pathname    # * Find *
-  #
-  # Iterates over the directory tree in a depth first manner, yielding a
-  # Pathname for each file under "this" directory.
-  #
-  # Note that you need to require 'pathname' to use this method.
-  #
-  # Returns an Enumerator if no block is given.
-  #
-  # Since it is implemented by the standard library module Find, Find.prune can
-  # be used to control the traversal.
-  #
-  # If +self+ is +.+, yielded pathnames begin with a filename in the
-  # current directory, not +./+.
-  #
-  # See Find.find
-  #
-  def find(ignore_error: true) # :yield: pathname
-    return to_enum(__method__, ignore_error: ignore_error) unless block_given?
-    require 'find'
-    if @path == '.'
-      Find.find(@path, ignore_error: ignore_error) {|f| yield self.class.new(f.delete_prefix('./')) }
-    else
-      Find.find(@path, ignore_error: ignore_error) {|f| yield self.class.new(f) }
-    end
-  end
-end
-
-
 class Pathname    # * FileUtils *
   # Recursively deletes a directory, including all directories beneath it.
   #

pathname_builtin.rb

@@ -1386,6 +1386,58 @@ def unlink()
 end
 
 class Pathname
+  # Iterates over the directory tree in a depth first manner, yielding a
+  # Pathname for each file under "this" directory.
+  #
+  # Returns an Enumerator if no block is given.
+  #
+  # If +self+ is +.+, yielded pathnames begin with a filename in the
+  # current directory, not +./+.
+  #
+  # If +ignore_error+ is true (the default), errors during traversal
+  # are silently ignored. If false, errors are raised.
+  #
+  #   Pathname("/usr/local").find {|f| p f }
+  #   #=> #<Pathname:/usr/local>
+  #   #=> #<Pathname:/usr/local/bin>
+  #   #=> ...
+  #
+  def find(ignore_error: true) # :yield: pathname
+    return to_enum(__method__, ignore_error: ignore_error) unless block_given?
+    fs_encoding = Encoding.find("filesystem")
+    enc = @path.encoding == Encoding::US_ASCII ? fs_encoding : @path.encoding
+    ps = [@path]
+    while file = ps.shift
+      catch(:prune) do
+        if @path == '.'
+          yield self.class.new(file == '.' ? file : file.delete_prefix('./'))
+        else
+          yield self.class.new(file)
+        end
+        begin
+          s = File.lstat(file)
+        rescue Errno::ENOENT, Errno::EACCES, Errno::ENOTDIR, Errno::ELOOP, Errno::ENAMETOOLONG, Errno::EINVAL
+          raise unless ignore_error
+          next
+        end
+        if s.directory? then
+          begin
+            fs = Dir.children(file, encoding: enc)
+          rescue Errno::ENOENT, Errno::EACCES, Errno::ENOTDIR, Errno::ELOOP, Errno::ENAMETOOLONG, Errno::EINVAL
+            raise unless ignore_error
+            next
+          end
+          fs.sort!
+          fs.reverse_each {|f|
+            f = File.join(file, f)
+            ps.unshift f
+          }
+        end
+      end
+    end
+    nil
+  end
+
   undef =~ if Kernel.method_defined?(:=~)
 end