# install in /etc/zsh/zshrc or your personal .zshrc
  
  # gc
  prefixes=(5 6 8)
  for p in $prefixes; do
  	compctl -g "*.${p}" ${p}l
  	compctl -g "*.go" ${p}g
  done
  
  # standard go tools
  compctl -g "*.go" gofmt
  
  # gccgo
  compctl -g "*.go" gccgo
  
  # go tool
  __go_tool_complete() {
    typeset -a commands build_flags
    commands+=(
      'build[compile packages and dependencies]'
      'clean[remove object files]'
      'doc[run godoc on package sources]'
      'env[print Go environment information]'
      'fix[run go tool fix on packages]'
      'fmt[run gofmt on package sources]'

      'generate[generate Go files by processing source]'

      'get[download and install packages and dependencies]'
      'help[display help]'
      'install[compile and install packages and dependencies]'
      'list[list packages]'
      'run[compile and run Go program]'
      'test[test packages]'
      'tool[run specified go tool]'
      'version[print Go version]'
      'vet[run go tool vet on packages]'
    )
    if (( CURRENT == 2 )); then
      # explain go commands
      _values 'go tool commands' ${commands[@]}
      return
    fi
    build_flags=(
      '-a[force reinstallation of packages that are already up-to-date]'
      '-n[print the commands but do not run them]'
      '-p[number of parallel builds]:number'
      '-race[enable data race detection]'
      '-x[print the commands]'
      '-work[print temporary directory name and keep it]'
      '-ccflags[flags for 5c/6c/8c]:flags'
      '-gcflags[flags for 5g/6g/8g]:flags'
      '-ldflags[flags for 5l/6l/8l]:flags'
      '-gccgoflags[flags for gccgo]:flags'
      '-compiler[name of compiler to use]:name'
      '-installsuffix[suffix to add to package directory]:suffix'
      '-tags[list of build tags to consider satisfied]:tags'
    )

    __go_packages() {
        local gopaths
        declare -a gopaths
        gopaths=("${(s/:/)$(go env GOPATH)}")
        gopaths+=("$(go env GOROOT)")
        for p in $gopaths; do
          _path_files -W "$p/src" -/
        done
    }
    __go_identifiers() {
        compadd $(godoc -templates $ZSH/plugins/golang/templates ${words[-2]} 2> /dev/null)

    }
    case ${words[2]} in

    doc)
      _arguments -s -w \
        "-c[symbol matching honors case (paths not affected)]" \
        "-cmd[show symbols with package docs even if package is a command]" \
        "-u[show unexported symbols as well as exported]" \
        "2:importpaths:__go_packages" \
        ":next identifiers:__go_identifiers"
        ;;
    clean)
      _arguments -s -w \
        "-i[remove the corresponding installed archive or binary (what 'go install' would create)]" \
        "-n[print the remove commands it would execute, but not run them]" \
        "-r[apply recursively to all the dependencies of the packages named by the import paths]" \
        "-x[print remove commands as it executes them]" \
        "*:importpaths:__go_packages"

        ;;
    fix|fmt|list|vet)

        _alternative ':importpaths:__go_packages' ':files:_path_files -g "*.go"'

        ;;
    install)
        _arguments -s -w : ${build_flags[@]} \
          "-v[show package names]" \

          '*:importpaths:__go_packages'

        ;;
    get)
        _arguments -s -w : \
          ${build_flags[@]}
        ;;
    build)
        _arguments -s -w : \
          ${build_flags[@]} \
          "-v[show package names]" \
          "-o[output file]:file:_files" \

          "*:args:{ _alternative ':importpaths:__go_packages' ':files:_path_files -g \"*.go\"' }"

        ;;
    test)
        _arguments -s -w : \
          ${build_flags[@]} \
          "-c[do not run, compile the test binary]" \
          "-i[do not run, install dependencies]" \
          "-v[print test output]" \
          "-x[print the commands]" \
          "-short[use short mode]" \
          "-parallel[number of parallel tests]:number" \
          "-cpu[values of GOMAXPROCS to use]:number list" \
          "-run[run tests and examples matching regexp]:regexp" \
          "-bench[run benchmarks matching regexp]:regexp" \
          "-benchmem[print memory allocation stats]" \
          "-benchtime[run each benchmark until taking this long]:duration" \
          "-blockprofile[write goroutine blocking profile to file]:file" \
          "-blockprofilerate[set sampling rate of goroutine blocking profile]:number" \
          "-timeout[kill test after that duration]:duration" \
          "-cpuprofile[write CPU profile to file]:file:_files" \
          "-memprofile[write heap profile to file]:file:_files" \
          "-memprofilerate[set heap profiling rate]:number" \

          "*:args:{ _alternative ':importpaths:__go_packages' ':files:_path_files -g \"*.go\"' }"

        ;;
    help)
        _values "${commands[@]}" \
          'gopath[GOPATH environment variable]' \
          'packages[description of package lists]' \
          'remote[remote import path syntax]' \
          'testflag[description of testing flags]' \
          'testfunc[description of testing functions]'
        ;;
    run)
        _arguments -s -w : \
            ${build_flags[@]} \
            '*:file:_path_files -g "*.go"'
        ;;
    tool)
        if (( CURRENT == 3 )); then
            _values "go tool" $(go tool)
            return
        fi
        case ${words[3]} in
        [568]g)
            _arguments -s -w : \
                '-I[search for packages in DIR]:includes:_path_files -/' \
                '-L[show full path in file:line prints]' \
                '-S[print the assembly language]' \
                '-V[print the compiler version]' \
                '-e[no limit on number of errors printed]' \
                '-h[panic on an error]' \
                '-l[disable inlining]' \
                '-m[print optimization decisions]' \
                '-o[file specify output file]:file' \
                '-p[assumed import path for this code]:importpath' \
                '-u[disable package unsafe]' \
                "*:file:_files -g '*.go'"
            ;;
        [568]l)
            local O=${words[3]%l}
            _arguments -s -w : \
                '-o[file specify output file]:file' \
                '-L[search for packages in DIR]:includes:_path_files -/' \
                "*:file:_files -g '*.[ao$O]'"
            ;;
        dist)
            _values "dist tool" banner bootstrap clean env install version
            ;;
        *)
            # use files by default
            _files
            ;;
        esac
        ;;
    esac
  }
  
  compdef __go_tool_complete go
  
  # aliases
  alias gfa='go fmt . ./...'