.zshrc (lazy loading shell functions)

.zshrc

# Copyright (c) 2016-2018 Ming Qin (覃明) <https://github.com/QinMing>
# Open source under MIT LICENSE.

lazy_load() {
    # Act as a stub to another shell function/command. When first run, it will load the actual function/command then execute it.
    # E.g. This made my zsh load 0.8 seconds faster by loading `nvm` when "nvm", "npm" or "node" is used for the first time
    # $1: space separated list of alias to release after the first load
    # $2: file to source
    # $3: name of the command to run after it's loaded
    # $4+: argv to be passed to $3
    echo "Lazy loading $1 ..."

    # $1.split(' ') using the s flag. In bash, this can be simply ($1) #http://unix.stackexchange.com/questions/28854/list-elements-with-spaces-in-zsh
    # Single line won't work: local names=("${(@s: :)${1}}"). Due to http://stackoverflow.com/questions/14917501/local-arrays-in-zsh   (zsh 5.0.8 (x86_64-apple-darwin15.0))
    local -a names
    if [[ -n "$ZSH_VERSION" ]]; then
        names=("${(@s: :)${1}}")
    else
        names=($1)
    fi
    unalias "${names[@]}"
    . $2
    shift 2
    $*
}

group_lazy_load() {
    local script
    script=$1
    shift 1
    for cmd in "$@"; do
        alias $cmd="lazy_load \"$*\" $script $cmd"
    done
}

export NVM_DIR=~/.nvm
group_lazy_load $HOME/.nvm/nvm.sh nvm node npm truffle gulp yarn

export PATH="$PATH:$HOME/.rvm/bin" # Add RVM to PATH for scripting
group_lazy_load $HOME/.rvm/scripts/rvm rvm irb rake rails

unset -f group_lazy_load

# simple python virtual environment wrapper
alias ve="lazy_load 've' $HOME/git/simple-virtualenv-wrapper/ve.sh ve"

my zsh thing used to take around 1.5 seconds not its like 0.4 seconds AWESOME