Additional clip copy options (#1028)

Addition to `clip` module (#1009):

* Passes complex values through `table -e` to render properly
* By default, strips ansi codes, unless `--ansi (-a)` switch is used
* Adds a `clip prefex` command which can accept a prefix string like `# => ` to be added to the
beginning of each line.

stdlib-candidate/std-rfc/clip/mod.nu

@@ -9,8 +9,29 @@
 # ```nushell
 # >_ "Hello" | clip copy
 # ```
-export def copy []: [string -> nothing] {
+export def copy [
-	print -n $'(ansi osc)52;c;($in | encode base64)(ansi st)'
+  --ansi (-a)                 # Copy ansi formatting
+]: any -> nothing {
+  let input = $in | collect
+  let text = match ($input | describe -d | get type) {
+    $type if $type in [ table, record, list ] => {
+      $input | table -e
+    }
+    _ => {$input}
+  }
+
+  let do_strip_ansi = match $ansi {
+    true  => {{||}}
+    false => {{|| ansi strip }}
+  }
+
+  let output = (
+    $text
+    | do $do_strip_ansi
+    | encode base64
+  )
+
+	print -n $'(ansi osc)52;c;($output)(ansi st)'
 }
 
 # Paste contenst of system clipboard
@@ -33,3 +54,18 @@ export def paste []: [nothing -> string] {
 	| decode base64
 	| decode
 }
+
+# Add a prefix to each line of the content to be copied
+#
+# # Example: Format output for Nushell doc
+# ls | clip prefix '# => ' | clip copy
+export def prefix [prefix: string]: any -> string {
+  let input = $in | collect
+  match ($input | describe -d | get type) {
+    $type if $type in [ table, record, list ] => {
+      $input | table -e
+    }
+    _ => {$input}
+  }
+  | str replace -r --all '(?m)(.*)' $'($prefix)$1'
+}