Closure over the local variables by wrapping everything in a anonymous function

Also namespace all the functions as they will always be global

pure.zsh

@@ -17,51 +17,54 @@
 # %m => shortname host
 # %(?..) => prompt conditional - %(condition.true.false)
 
-autoload -Uz add-zsh-hook
-autoload -Uz vcs_info
 
-add-zsh-hook precmd pure_precmd
-add-zsh-hook preexec pure_preexec
+() {
+	autoload -Uz add-zsh-hook
+	autoload -Uz vcs_info
 
-zstyle ':vcs_info:*' enable git # You can add hg too if needed: `git hg`
-zstyle ':vcs_info:git*' formats ' %b'
-zstyle ':vcs_info:git*' actionformats ' %b|%a'
+	add-zsh-hook precmd pure_precmd
+	add-zsh-hook preexec pure_preexec
 
-# enable prompt substitution
-setopt PROMPT_SUBST
+	zstyle ':vcs_info:*' enable git # You can add hg too if needed: `git hg`
+	zstyle ':vcs_info:git*' formats ' %b'
+	zstyle ':vcs_info:git*' actionformats ' %b|%a'
 
-# only show username if not default
-[ $USER != "$PURE_DEFAULT_USERNAME" ] && local username='%n@%m '
+	# enable prompt substitution
+	setopt PROMPT_SUBST
 
-# fastest possible way to check if repo is dirty
-git_dirty() {
-	# check if we're in a git repo
-	command git rev-parse --is-inside-work-tree &>/dev/null || return
-	# check if it's dirty
-	command git diff --quiet --ignore-submodules HEAD &>/dev/null; [ $? -eq 1 ] && echo '*'
+	# only show username if not default
+	[ $USER != "$PURE_DEFAULT_USERNAME" ] && local username='%n@%m '
+
+	# fastest possible way to check if repo is dirty
+	pure_git_dirty() {
+		# check if we're in a git repo
+		command git rev-parse --is-inside-work-tree &>/dev/null || return
+		# check if it's dirty
+		command git diff --quiet --ignore-submodules HEAD &>/dev/null; [ $? -eq 1 ] && echo '*'
+	}
+
+	# displays the exec time of the last command if set threshold was exceeded
+	pure_cmd_exec_time() {
+		local stop=`date +%s`
+		local start=${cmd_timestamp:-$stop}
+		let local elapsed=$stop-$start
+		[ $elapsed -gt "${PURE_CMD_MAX_EXEC_TIME:=5}" ] && echo ${elapsed}s
+	}
+
+	pure_preexec() {
+		cmd_timestamp=`date +%s`
+	}
+
+	pure_precmd() {
+		vcs_info
+		# add `%*` to display the time
+		print -P '\n%F{blue}%~%F{8}$vcs_info_msg_0_`pure_git_dirty` $username%f %F{yellow}`pure_cmd_exec_time`%f'
+		# reset value since `preexec` isn't always triggered
+		unset cmd_timestamp
+	}
+
+	# prompt turns red if the previous command didn't exit with 0
+	PROMPT='%(?.%F{magenta}.%F{red})❯%f '
+	# can be disabled:
+	# PROMPT='%F{magenta}❯%f '
 }
-
-# displays the exec time of the last command if set threshold was exceeded
-cmd_exec_time() {
-	local stop=`date +%s`
-	local start=${cmd_timestamp:-$stop}
-	let local elapsed=$stop-$start
-	[ $elapsed -gt "${PURE_CMD_MAX_EXEC_TIME:=5}" ] && echo ${elapsed}s
-}
-
-pure_preexec() {
-	cmd_timestamp=`date +%s`
-}
-
-pure_precmd() {
-	vcs_info
-	# add `%*` to display the time
-	print -P '\n%F{blue}%~%F{8}$vcs_info_msg_0_`git_dirty` $username%f %F{yellow}`cmd_exec_time`%f'
-	# reset value since `preexec` isn't always triggered
-	unset cmd_timestamp
-}
-
-# prompt turns red if the previous command didn't exit with 0
-PROMPT='%(?.%F{magenta}.%F{red})❯%f '
-# can be disabled:
-# PROMPT='%F{magenta}❯%f '