Add fisk theme

themes/fisk/README.md

+# Fisk
+
+![theme screenshot](https://cloud.githubusercontent.com/assets/20814/6209746/60949aa6-b5c9-11e4-8edc-5a8e370f4527.png)
+
+A nice dark blue-green theme with support for:
+
+- Last exit code
+- Current git HEAD
+- Current python virtualenv
+
+By [joar](https://github.com/joar), thanks to
+[adisbladis](https://github.com/adisbladis) for the starting point.

themes/fisk/concat.fish

+function concat
+  for i in $argv
+    echo -n $i;
+  end
+end

themes/fisk/fish_prompt.fish

+function fish_prompt --description 'Write out the prompt'
+  set last_ret $status
+  # Just calculate these once, to save a few cycles when displaying the prompt
+  if not set -q __fish_prompt_hostname
+    set -g __fish_prompt_hostname (hostname|cut -d . -f 1)
+  end
+
+  if not set -q __fish_prompt_cwd
+    set -g __fish_prompt_cwd (set_color $fish_color_cwd)
+  end
+
+   /if set -q VIRTUAL_ENV
+    set venv (echo -n -s " " (set_color ff00de) "(" (basename "$VIRTUAL_ENV") ")" (set_color normal))
+  else
+    set venv ""
+  end
+
+  git branch >  /dev/null ^ /dev/null
+  if [ $status = 0 ]
+    set branch (concat (set_color -o blue) "(" (basename (git rev-parse --show-toplevel)) ")")
+  else
+    set branch ""
+  end
+
+  set ret_color 7f7
+
+  if [ $last_ret -gt 0 ]
+    set ret_color f77
+  end
+
+  set -l ret_part (concat \
+    (set_color 777) '[' \
+    (set_color $ret_color) $last_ret \
+    (set_color 777) ']' \
+  )
+
+  set -l user_part (concat \
+    (set_color 55f) $USER \
+    (set_color 55a) @ \
+    (set_color 55f) $__fish_prompt_hostname \
+  )
+
+  set -l _context_part (concat \
+    "$__fish_prompt_cwd" (prompt_pwd) "$venv" (set_color -o yellow) (__fish_git_prompt) \
+  )
+
+  set -l prompt_end (concat (set_color 55f) '➞')
+
+  echo -n (concat $ret_part " " $user_part " " $_context_part " " $prompt_end (set_color normal) " ")
+end