[io grant] Add "What's an IO::Path Anyway?" section to TDIOG

Author: zoffixznet

doc/Language/io-guide.pod6

@@ -29,6 +29,37 @@ functional programming style or in Perl 6 one liners.
 While L<IO::Socket> and its subclasses also have to do with Input and Output,
 this guide does not cover them.
 
+=head1 Navigating Paths
+
+=head2 What's an IO::Path Anyway?
+
+To represent paths to either files or directories, use L<IO::Path> type.
+The simplest way to obtain an object of that type is to coerce a L<Str> by
+calling L«C<.IO>|/routine/IO» method on it:
+
+    say 'my-file.txt'.IO; # OUTPUT: «"my-file.txt".IO␤»
+
+It may seem like something is missing here—there is no volume or absolute
+path involved—but that information is actually present in the object. You can
+see it by using L«C<.perl>|/routine/perl» method:
+
+    say 'my-file.txt'.IO.perl;
+    # OUTPUT: «IO::Path.new("my-file.txt", :SPEC(IO::Spec::Unix), :CWD("/home/camelia"))␤»
+
+The two extra attributes—C<SPEC> and C<CWD>—specify what type of operating
+system semantics the path should use as well as the "current working directory"
+for the path, i.e. if it's a relative path, then it's relative to that
+directory.
+
+This means that regardless of how you made one, an L<IO::Path> object
+technically always refers to an absolute path. This is why its
+L«C<.absolute>|/routine/absolute» and L«C<.relative>|/routine/relative»
+methods return L<Str> objects and they are the correct way to stringify a path.
+
+However, don't be in a rush to stringify anything. Pass paths around as
+L<IO::Path|/type/IO::Path> objects. All the routines that operate on paths
+can handle them, so there's no need to convert them.
+
 =head1 The Wrong Way To Do Things
 
 This section describes how NOT to do Perl 6 IO.