prezto/helper.zsh

#
# Defines helper functions.
#
# Authors:
#   Sorin Ionescu <sorin.ionescu@gmail.com>
#

# Checks boolean variable for "true".
# Case insensitive: "1", "y", "yes", "t", "true", "o", and "on".
function is-true {
  [[ -n "$1" && "$1" == (1|[Yy]([Ee][Ss]|)|[Tt]([Rr][Uu][Ee]|)|[Oo]([Nn]|)) ]]
}

# Prints the first non-empty string in the arguments array.
function coalesce {
  for arg in $argv; do
    print "$arg"
    return 0
  done
  return 1
}

# Checks if a file can be autoloaded by trying to load it in a subshell.
function autoloadable {
  ( unfunction $1 ; autoload -U +X $1 ) &> /dev/null
}

# Loads Oh My Zsh modules.
function omodload {
  local omodule

  # Extended globbing is needed for autoloading of module functions.
  setopt EXTENDED_GLOB

  # Add functions and completions to fpath.
  fpath=(${argv:+${OMZ}/modules/${^argv}/{functions,completions}(/FN)} $fpath)

  # Load Oh My Zsh functions.
  for ofunction in $OMZ/modules/**/functions/^([_.]*|prompt_*_setup)(.N:t); do
    autoload -Uz "$ofunction"
  done
  unset ofunction

  # Extended globbing is no longer needed.
  unsetopt EXTENDED_GLOB

  for omodule in "$argv[@]"; do
    if zstyle -t ":omz:module:$omodule" loaded; then
      continue
    elif [[ ! -d "$OMZ/modules/$omodule" ]]; then
      print "$0: no such module: $omodule" >&2
      continue
    else
      if [[ -f "$OMZ/modules/$omodule/init.zsh" ]]; then
        source "$OMZ/modules/$omodule/init.zsh"
      fi

      if (( $? == 0 )); then
        zstyle ":omz:module:$omodule" loaded 'yes'
      else
        zstyle ":omz:module:$omodule" loaded 'no'
      fi
    fi
  done
}

# Trap signals were generated with 'kill -l'.
# DEBUG, EXIT, and ZERR are Zsh signals.
TRAP_SIGNALS=(
  ABRT ALRM BUS CHLD CONT EMT FPE HUP ILL INFO INT IO KILL PIPE PROF QUIT
  SEGV STOP SYS TERM TRAP TSTP TTIN TTOU URG USR1 USR2 VTALRM WINCH XCPU XFSZ
  DEBUG EXIT ZERR
)

# Adds a function to a list to be called when a trap is triggered.
function add-zsh-trap {
  if (( $# < 2 )); then
    print "usage: $0 type function" >&2
    return 1
  fi

  if [[ -z "$TRAP_SIGNALS[(r)$1]" ]]; then
    print "$0: unknown signal: $1" >&2
    return 1
  fi

  local trap_functions="TRAP${1}_FUNCTIONS"
  if (( ! ${(P)+trap_functions} )); then
    typeset -gaU "$trap_functions"
  fi
  eval "$trap_functions+="$2""

  if (( ! $+functions[TRAP${1}] )); then
    eval "
     function TRAP${1} {
        for trap_function in \"\$TRAP${1}_FUNCTIONS[@]\"; do
          if (( \$+functions[\$trap_function] )); then
            \"\$trap_function\" \"\$1\"
          fi
        done
        return \$(( 128 + \$1 ))
     }
    "
  fi
}