Re: [PATCH] Add customizable `vcs` prompt theme (was Re: [RFC][PATCH] `newuser` prompt theme)

[Marlon Richert <marlon.richert@xxxxxxxxx>]

On Thu, Jun 10, 2021 at 12:30 PM Roman Perepelitsa
<roman.perepelitsa@xxxxxxxxx> wrote:
>
> There is //'%%'/% in a few places. What's the logic behind it?

Some prompt escape codes (such as %b for bold) need %% when used in
vcs_info -- except when they are used in nvcsformats.


> I think invoking prompt_vcs_setup twice in the same shell will produce
> an error. I haven't tried it though.

I just tried it and I didn't get any errors. Why do you think it would
produce an error?


> prompt_vcs_chpwd always prints at least one line to the TTY regardless
> of configuration options. Is this intended?

Yes, that was my intention, but I can see how it could be useful to be
able to customize that. I'll change it.


> Why is prompt_vcs_precmd checking whether prompt_vcs_fd is a readable
> fd? How can it not be?

I don't know how or why, but if I don't check for that, then I get
this error repeatedly:

prompt_vcs_precmd:6: failed to close file descriptor 11: bad file descriptor


> There is a comment in prompt_vcs_precmd that says it's going to kill a
> process while in fact it closes the file descriptor. That may
> *eventually* kill the process when it decides to print something
> (assuming it hasn't blocked SIGPIPE or is checking for write errors).

True. I'll change it to actually kill the process, too.


> What is the purpose of the "Info is not for current dir" check? Is
> this to account for the possibility of `cd` from a zle widget? If so,
> perhaps handle this by hooking chpwd?

The purpose is to account for the possibility that we receive the info
_after_ we've already changed to a new dir. However, if I correct the
piece of code you mentioned previously, then that shouldn't be
necessary.


> prompt_vcs_fd-widget has a check for [[ -n $1 ]]. When is it false?

When prompt_vcs_fd-widget is being called incorrectly. :) Perhaps it
should not return 1 in that case, though.


Thanks again. New version of the patch attached.

From 11f84b43e90854ae4c03aa072e110ec494da2d33 Mon Sep 17 00:00:00 2001
From: Marlon Richert <marlon.richert@xxxxxxxxx>
Date: Thu, 10 Jun 2021 16:45:30 +0300
Subject: [PATCH] Add customizable `vcs` prompt theme

---
 Functions/Prompts/prompt_vcs_setup | 199 +++++++++++++++++++++++++++++
 1 file changed, 199 insertions(+)
 create mode 100644 Functions/Prompts/prompt_vcs_setup

diff --git a/Functions/Prompts/prompt_vcs_setup b/Functions/Prompts/prompt_vcs_setup
new file mode 100644
index 000000000..c2f2e6cde
--- /dev/null
+++ b/Functions/Prompts/prompt_vcs_setup
@@ -0,0 +1,199 @@
+##
+# Prompt that can be customized through vcs_info
+#
+zmodload -F zsh/system p:sysparams
+autoload -Uz add-zle-hook-widget add-zsh-hook vcs_info
+
+# Prompt segments
+# Normal %b and %(...) need extra % in vcs_info -- except in nvcsformats.
+readonly -gHA _prompt_vcs_ps1_default=(
+    left      $'%%(?,%F{green},%F{red})%#%%b%f%%s '
+    right     '%B%F{blue}%n%b%f%k@%F{magenta}%m%f'
+    chpwd     $'\n%B%F{blue}%~%%b%f/\n'
+    staged    '%B%F{green}+%b%f'
+    unstaged  '%B%F{red}*%b%f'
+    action    '%B%F{red}%a%%b%f'
+    branch    '%B%F{cyan}%b%%b%f'
+    repo      '|%B%F{blue}%r%%b%f'
+)
+
+prompt_vcs_help() {
+  print -r -- \
+"Customizable prompt theme that includes VCS info for the current dir (for
+example, git status) and asynchronously checks for repo changes.
+
+To customize it, copy-paste any of the code below to your .zshrc file and edit
+it there:
+
+  # For each of the following three entries:
+  #   1st string is the left prompt.
+  #   2nd string is the right prompt.
+  #   3rd string is printed whenever you change dirs (before the left prompt).
+
+  # Normal prompt:
+  zstyle ':vcs_info:*:prompt_vcs:*' nvcsformats \\
+      "${(q+)_prompt_vcs_ps1_default[left]//'%%'/%}" \\
+      "${(q+)_prompt_vcs_ps1_default[right]//'%%'/%}" \\
+      "${(q+)_prompt_vcs_ps1_default[chpwd]//'%%'/%}"
+
+  # Prompt inside VCS repo:
+  zstyle ':vcs_info:*:prompt_vcs:*' formats \\
+      ${(q+)_prompt_vcs_ps1_default[left]} \\
+      ${(q+):-%u%c$_prompt_vcs_ps1_default[branch]$_prompt_vcs_ps1_default[repo]} \\
+      ${(q+)_prompt_vcs_ps1_default[chpwd]}
+
+  # Prompt during ongoing VCS action:
+  zstyle ':vcs_info:*:prompt_vcs:*' actionformats \\
+      ${(q+)_prompt_vcs_ps1_default[left]} \\
+      ${(q+):-%u%c$_prompt_vcs_ps1_default[action]$_prompt_vcs_ps1_default[repo]} \\
+      ${(q+)_prompt_vcs_ps1_default[chpwd]}
+
+  # These customize the values of %c and %u, respectively:
+  zstyle ':vcs_info:*:prompt_vcs:*' stagedstr ${(q+)_prompt_vcs_ps1_default[staged]}
+  zstyle ':vcs_info:*:prompt_vcs:*' unstagedstr ${(q+)_prompt_vcs_ps1_default[unstaged]}
+
+For more info on the settings above, see
+http://zsh.sourceforge.net/Doc/Release/Prompt-Expansion.html and the end of
+http://zsh.sourceforge.net/Doc/Release/User-Contributions.html#vcs_005finfo-Configuration";
+}
+
+# Sets a style if it hasn't been set yet.
+_prompt_vcs_zstyle() {
+  local -a val
+  zstyle -g val "$1" "$2"
+  (( $#val )) ||
+      zstyle "$@"
+}
+
+_prompt_vcs_info() {
+  _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' max-exports 3 # Default is 2.
+
+  _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' nvcsformats \
+      "${_prompt_vcs_ps1_default[left]//'%%'/%}" \
+      "${_prompt_vcs_ps1_default[right]//'%%'/%}" \
+      "${_prompt_vcs_ps1_default[chpwd]//'%%'/%}"
+
+  _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' formats \
+      "$_prompt_vcs_ps1_default[left]" \
+      "%u%c$_prompt_vcs_ps1_default[branch]$_prompt_vcs_ps1_default[repo]" \
+      "$_prompt_vcs_ps1_default[chpwd]"
+
+  _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' actionformats \
+      "$_prompt_vcs_ps1_default[left]" \
+      "%u%c$_prompt_vcs_ps1_default[action]$_prompt_vcs_ps1_default[repo]" \
+      "$_prompt_vcs_ps1_default[chpwd]"
+
+  _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' stagedstr \
+      "$_prompt_vcs_ps1_default[staged]"
+
+  _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' unstagedstr \
+      "$_prompt_vcs_ps1_default[unstaged]"
+
+  vcs_info prompt_vcs # Call with namespace.
+
+  print -rNC1 -- \
+      "${(q+)vcs_info_msg_0_}" "${(q+)vcs_info_msg_1_}" "${(q+)vcs_info_msg_2_}"
+}
+
+prompt_vcs_chpwd() {
+  emulate -L zsh
+
+  # Don't check for changes at this point, for performance reasons.
+  typeset -ga _prompt_vcs_info_msg_=( "${(0@Q)$(
+    _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' check-for-changes no
+    _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' check-for-staged-changes no
+    _prompt_vcs_info
+  )}" )
+  PS1="$_prompt_vcs_info_msg_[1]"
+  RPS1="$_prompt_vcs_info_msg_[2]"
+  print -nPr -- "$_prompt_vcs_info_msg_[3]"
+}
+
+# We need to use line-init instead of precmd, because any widget can
+# potentially change the state of the repo or change dir without accepting or
+# aborting the command line.
+prompt_vcs_line-init() {
+  emulate -L zsh
+
+  # Terminate any pending vcs_info request before starting a new one.
+  # Second test checks if fd is readable, to avoid this error being printed:
+  #   failed to close file descriptor XX: bad file descriptor
+  if (( prompt_vcs_fd )) && { : <&$prompt_vcs_fd } 2>/dev/null; then
+    zle -F "$prompt_vcs_fd" 2> /dev/null
+    exec {prompt_vcs_fd}<&-
+  fi
+  if (( prompt_vcs_pid )); then
+    [[ -o monitor ]] &&
+        (( prompt_vcs_pid *= -1 ))
+    kill -KILL $prompt_vcs_pid 2> /dev/null
+  fi
+
+  # Asynchronously check for changes.
+  typeset -gH prompt_vcs_fd=
+  exec {prompt_vcs_fd}< <(
+	  print -r -- $sysparams[pid]
+    _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' check-for-changes yes
+    _prompt_vcs_zstyle ':vcs_info:*:prompt_vcs:*' check-for-staged-changes yes
+    _prompt_vcs_info
+  )
+  typeset -gH prompt_vcs_pid=
+  read -u $prompt_vcs_fd -- prompt_vcs_pid
+
+  # Add callback. Needs to be a widget, so we can refresh the prompt.
+  zle -Fw "$prompt_vcs_fd" prompt_vcs_fd-widget
+}
+
+# Callback widget for our async fetch of VCS changes
+zle -N prompt_vcs_fd-widget
+prompt_vcs_fd-widget() {
+  emulate -L zsh
+
+  (( $1 )) ||
+      return 64  # EX_USAGE; see man 3 sysexits
+
+  local -i fd=$1
+  local -a reply
+  {
+    zle -F "$fd"  # Detach ourselves, so we don't get called more than once.
+
+    [[ -z $2 ]] ||
+        return 74  # EX_IOERR
+
+    IFS=$'\0' read -Aru "$fd"
+    typeset -gHa _prompt_vcs_info_msg_=( "${(@Q)reply}" )
+    PS1="$_prompt_vcs_info_msg_[1]"
+    RPS1="$_prompt_vcs_info_msg_[2]"
+    zle .reset-prompt
+  } always {
+    exec {fd}<&-
+  }
+}
+
+prompt_vcs_setup() {
+  prompt_opts=( cr percent sp ) # Tell promptinit which options to set.
+
+  # Indent left continuation prompt for each open shell construct.
+  local -a indent=( '%('{1..36}'_,  ,)' )
+  PS2="${(j::)indent}"
+  RPS2='%F{yellow}# %^%f'
+  
+  PS4=$'#->%(?,%F{green},%B%F{red}%S)%?%b%f%s\t%e+%F{green}%1N%f:%I'
+  PS4+='  %(1_,%F{yellow}%K{black}%_%f%k ,)'
+  SPROMPT='Correct %B%F{red}%S%R%b%f%s to %B%F{green}%r%b%f?'
+  SPROMPT+=$'\n%{\e[2m%}%Uy%ues %Un%uo %Ue%udit %Ua%ubort%b '
+  PROMPT_EOL_MARK='%F{cyan}%S%#%f%s'
+  zle_highlight=(
+      isearch:fg=black,bg=yellow
+      special:fg=cyan,bold
+      region:fg=white,bg=blue,bold
+      suffix:fg=white,bg=blue,bold
+      paste:bold
+  )
+
+  add-zsh-hook chpwd prompt_vcs_chpwd
+  add-zle-hook-widget line-init prompt_vcs_line-init
+
+  prompt_vcs_chpwd
+}
+
+prompt_vcs_setup "$@"
-- 
2.30.1 (Apple Git-130)