SYNOPSIS

    See Perinci::CmdLine::Manual::Examples.

DESCRIPTION

    Perinci::CmdLine::Lite (hereby P::C::Lite) is a lightweight (low
    startup overhead, minimal dependencies) alternative to Perinci::CmdLine
    (hereby P::C). It offers a subset of functionality and a compatible
    API. Unless you use the unsupported features of P::C, P::C::Lite is a
    drop-in replacement for P::C (also see Perinci::CmdLine::Any for
    automatic fallback).

    P::C::Lite stays lightweight by avoiding the use of libraries that have
    large dependencies or add too much to startup overhead. This includes
    Perinci::Access for metadata access, Data::Sah for validator
    generation, Text::ANSITable for formatting results, and Log::Any::App
    (which uses Log::Log4perl) for logging.

    P::C::Lite attributes default to condition of low startup overhead. For
    example, log is by default off instead of on like in P::C.

    I first developed P::C::Lite mainly for CLI applications that utilize
    shell tab completion as their main feature, e.g. App::PMUtils,
    App::ProgUtils, App::GitUtils.

    Below is summary of the differences between P::C::Lite and P::C:

      * P::C::Lite starts much faster

      The target is under 0.04-0.05s to make shell tab completion
      convenient. On the other hand, P::C can start between 0.20-0.50s.

      * P::C::Lite uses simpler formatting

      Instead of Perinci::Result::Format (especially for 'text*' formats
      which use Data::Format::Pretty::Console and Text::ANSITable), to keep
      dependencies minimal and formatting quick, P::C::Lite uses the
      following simple rules that work for a significant portion of common
      data structures:

      1) if result is undef, print nothing.

      2) if result is scalar, print it (with newline automatically added).

      3) if result is an array of scalars (check at most 5 first rows),
      print it one line for each element.

      4) if result is a hash of scalars (check at most 5 keys), print a two
      column table, first column is key and second column is value. Keys
      will be sorted.

      5) if result is an array of hashes of scalars (check at most 5
      elements), print as table.

      6) if result is an array of arrays of scalars (check at most 5
      elements), print as table.

      7) otherwise print as JSON (after cleaning it with
      Data::Clean::JSON).

      YAML and the other formats are not supported.

      Table is printed using the more lightweight and much faster
      Text::Table::Tiny.

      * No support for some protocols

      Instead of Perinci::Access, this module uses the more lightweight
      alternative Perinci::Access::Lite which does not support some URL
      schemes (http/https and local are supported though).

      * No automatic validation from schema in P::C::Lite

      Since code wrapping and schema code generation done by
      Perinci::Sub::Wrapper and Data::Sah (which are called automatically
      by Perinci::Access, but not by Perinci::Access::Lite) adds too much
      startup overhead.

      * P::C::Lite does not support color themes

      * P::C::Lite does not support undo

      * P::C::Lite currently has simpler logging

      Only logging to screen is supported, using
      Log::Any::Adapter::ScreenColoredLevel.

      * P::C::Lite does not support progress indicator

      * P::C::Lite does not support I18N

      * P::C::Lite does not yet support these environment variables

       PERINCI_CMDLINE_COLOR_THEME
       PERINCI_CMDLINE_SERVER
       PROGRESS
       COLOR
       UTF8

      * In passing command-line object to functions, P::C::Lite object is
      passed

      Some functions might expect a Perinci::CmdLine instance.

REQUEST KEYS

    All those supported by Perinci::CmdLine::Base, plus:

      * naked_res => bool

      Set to true if user specifies --naked-res.

ATTRIBUTES

    All the attributes of Perinci::CmdLine::Base, plus:

 log => bool (default: 0, or from env)

    Whether to enable logging. This currently means setting up
    Log::Any::Adapter to display logging (set in hook_after_parse_argv, so
    tab completion skips this step). To produce log, you use Log::Any in
    your code.

    The default is off. If you set LOG=1 or LOG_LEVEL or
    TRACE/DEBUG/VERBOSE/QUIET, then the default will be on. It defaults to
    off if you set LOG=0 or LOG_LEVEL=off.

 log_level => str (default: warning, or from env)

    Set default log level. The default can also be set via
    LOG_LEVEL/TRACE/DEBUG/VERBOSE/QUIET.

METHODS

    All the methods of Perinci::CmdLine::Base, plus:

ENVIRONMENT

    All the environment variables that Perinci::CmdLine::Base supports,
    plus:

 DEBUG

    Set log level to 'debug'.

 VERBOSE

    Set log level to 'info'.

 QUIET

    Set log level to 'error'.

 TRACE

    Set log level to 'trace'.

 LOG_LEVEL

    Set log level.

RESULT METADATA

    All those supported by Perinci::CmdLine::Base, plus:

 x.hint.result_binary => bool

    If set to true, then when formatting to text formats, this class won't
    print any newline to keep the data being printed unmodified.

SEE ALSO

    Perinci::CmdLine, Perinci::CmdLine::Manual

    Perinci::CmdLine::Any

