Revision history for Spp

0.01    2015-11-1
        First version, released on an unsuspecting world.

0.02    2015-11-2
        to-rule use JSON function encode_json.

0.03    2015-12-2
        repl spp is interface of spp

0.04    2017-08-14
        Spp as Parser of grammar, not entire language like lisp

1.01    2017-08-18
        Spp could use as app to test

1.02    2017-8-21
        fix bug could not install. readme add some content.

1.03    2017-8-29
        fix some bug, add string and str to Str

1.04    2017-8-29
        rewrite repl and Spp.pm

1.05    2017-8-29
        delete two no use function, is_str_atom() rename is_str()

1.06    2017-8-31
        name match atom add pos info [line,from,len]

1.07    2017-8-31
        add mode to control debug and get pos
        mode = 0 (default) not debug and pos
        mode = 1 debug matching
        mode = 2 get pos information of Token

1.08    2017-9-1
        match if return false, then set max match report str return.
        ['false', max_report]

1.09    2017-9-2
        to_end() set to Spp::Tools, could share with Mylisp.pm
        add spp_to_spp to test Spp could transfer itself to itself.
        add three test case.

1.10    2017-9-3
        Spp::Tools rename => Spp::Builtin
        would define function register Stable could have type sign
        Do not need re-write with Mylisp. Must implement by other
        language.

1.11    2017-9-4
        add get_matcher() match_matcher()
        could use 'Int Int+' match 'Int Int'
        type validation use type signature to check argument type gather.
        'Str Any' could match 'Str Str'

1.12    2017-9-4
        Spp.pm export grammar_to_ast() ast_to_parser() then other language
        Could backup ast to Json, then load it when use. also could load
        from grammar_text. but more quickly.

1.13    2017-9-4
        write_file would send a message to output when write ok!
        perl-tidy all source code.