I've decided to create JAPH using Parse::RecDescent module.

$;=Parse'RecDescent=>print+map{@$_}(eval("use $;;$;->new(q&
prog:{\$b='a'} lexema(s)
lexema:/\\d*/ {\$a=\$item[1]}
('-'{' '}|'^'{\$b++while\$a--;\$b}|','{\$b=[reverse'a'..\$b]->[\$a]})
&)")->prog('9^11^2,1^-19,13^1^5^12,3,13^-2,11,13^6,-4,7,2^8^6,13^'));
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Among other things, it was helpful to get a little training on that marvellously interesting and useful module, one of most important bricks in current Perl6 development.

Courage, the Cowardly Dog