shorten pwd if it gets too long and other small changes

zsh/.zshrc

@@ -49,18 +49,19 @@ zstyle ':vcs_info:*' formats "[%{$fg_bold[cyan]%}%b%{$reset_color%}]"
 zstyle ':vcs_info:*' actionformats "[%{$fg_bold[cyan]%}%b%{$reset_color%}|%a]"
 
 if [[ -f /run/.containerenv && -f /run/.toolboxenv ]]; then
-  TOOLBOX="%F{13}⬢%f "
+  PREFIX="%F{13}⬢%f"
+elif [[ "$NIX_PATH" && "$NIX_PROFILES" && "$NIX_CONF_DIR" ]]; then
+  PREFIX="%F{4}❄%f"
 else
-  TOOLBOX=""
+  PREFIX=""
 fi
 
-if [[ "$NIX_PATH" && "$NIX_PROFILES" && "$NIX_CONF_DIR" ]]; then
-  NIX_CHROOT="%F{4}❄%f "
-else
-  NIX_CHROOT=""
-fi
+# cut shown $PWD if depth is 5 or more ('~' counts)
+TRUNCATED_PWD="%(5~|.../%3~|%~)"
+# cut shown $PWD after 20 characters
+#TRUNCATED_PWD="%20<...<%~%<<"
 
-PROMPT="${NIX_CHROOT}${TOOLBOX}(%M) %~ %{$fg[red]%}%(#~#~$)%{$reset_color%} "
+PROMPT="${PREFIX} (%M) ${TRUNCATED_PWD} %{$fg[red]%}%(#~#~$)%{$reset_color%} "
 RPROMPT="\$vcs_info_msg_0_"
 
 precmd () {