git alias quoting help

I've also tried to make this a plain bash script (w/o the function or if statements and am failing at the same place). The issue seems to be with the quoting in the filter-branch | ls-files bit. Also, the end goal here is to be able to move a directory from one repo and keep the history. While this works if I do it at the command line, it's just too many steps (is tedious). Also, if there's a way to do the same thing with multiple directories in one shot, (or make this work with something like: cookbooks/{a,b,c} # as a parameter) that'd be perfect.

  reapdir = "!f() { \
    if [ -d "$1" ] ; then \
      git filter-branch --prune-empty --subdirectory-filter "$1" -- --all && \
      git gc --aggressive && \
      git prune && \
      git filter-branch -f --prune-empty --index-filter '\
        git ls-files -s \
          | sed \"s-\\t-&$1-\" \
          | GIT_INDEX_FILE=$GIT_INDEX_FILE.new git update-index
--index-info && \
            mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE'; \
    else \
      echo "No directory $1"; \
    fi; }; \
  f"