Add perl-info function

modules/perl/README.md

@@ -51,6 +51,24 @@ Aliases
   - `plbu` uninstalls a Perl version.
   - `plbx` temporarily sets the Perl version to use.
 
+Functions
+---------
+
+  - `perl-info` exposes information about the Perl environment via the
+    `$perl_info` associative array.
+
+Theming
+-------
+
+To display the name of the currach Perl version in a prompt, define the
+following style in the `prompt_name_setup` function.
+
+    # %v - perl version.
+    zstyle ':prezto:module:perl:info:version' format 'version:%v'
+
+Then add `$perl_info[version]` to `$PROMPT` or `$RPROMPT` and call
+`perl-info` in the `prompt_name_precmd` hook function.
+
 Authors
 -------
 

modules/perl/functions/perl-info

@@ -0,0 +1,30 @@
+#
+# Exposes information about the Perl environment via the $perl_info associative
+# array.
+#
+# Authors:
+#   JINNOUCHI Yasushi <delphinus@remora.cx>
+#
+
+local version
+local version_format
+local version_formatted
+
+# Clean up previous $perl_info.
+unset perl_info
+typeset -gA perl_info
+
+if (( $+commands[perlbrew] )); then
+  version=${${(F)${(f)"$(perlbrew list)"}:# *}[(w)2]}
+elif (( $+commands[plenv] )); then
+  version=$(plenv version-name)
+elif (( $+commands[perl] )); then
+  version=$(perl -e 'printf "%vd", $^V')
+fi
+
+# Format version.
+if [[ -n "$version" ]]; then
+  zstyle -s ':prezto:module:perl:info:version' format 'version_format'
+  zformat -f version_formatted "$version_format" "v:$version"
+  perl_info[version]="$version_formatted"
+fi