git module; adds rprompt string and auto-inits git-lfs if needed

modules/git.zsh

@@ -0,0 +1,34 @@
+(( $+commands[git] )) || return
+
+if (( $+commands[git-lfs] )); then
+    # ensures git-lfs is functional if installed
+    git config --get filter.lfs.process &> /dev/null || git lfs install
+fi
+
+function git_prompt() {
+    git rev-parse --is-inside-work-tree &> /dev/null
+    __git_prompt__is_git_dir=$?
+
+    if [[ $__git_prompt__is_git_dir -eq 0 ]]; then
+        commithash=$(git log --pretty=format:"%h" -n 1)
+        fullbranchname=$(git name-rev --name-only ${commithash})
+        branchtype=$(echo ${fullbranchname} | cut -d"/" -f1)
+
+        if [[ "${branchtype}" == "refs" ]]; then
+            branchname=$(echo ${fullbranchname} | cut -d"/" -f3)
+        elif [[ "${branchtype}" == "remotes" ]]; then
+            branchname=$(echo ${commithash} | cut -d"/" -f2-)
+        elif [[ "${branchtype}" == "${fullbranchname}" ]]; then
+            # git did it for us
+            branchname=${fullbranchname}
+        else
+            branchname=${fullbranchname}
+            # output a warning to stderr, convenience for maintenance
+            echo "warning: unrecognized branch type ${branchtype}" >&2
+        fi
+
+        print "%{$fg[yellow]%}${branchname}"
+    fi
+}
+
+rprompt_functions+=git_prompt