Draconis makes a good point.
The regular expression can be updated to allow correct handling of multiple-command input (to an extent), but it’s an inherently problematic approach.
It’s only “to an extent” because there is an inherent issue with the parser’s handling of topics that appear at the end of a grammar line (i.e. after any other words used to recognize the command). As seen in a recent thread on the I6 forum, the token that recognizes topics does not recognize command separators such as “.” or “then”, so it simply converts all remaining input to the topic. Thus, for a command like >X ME THEN A DOG THEN JUMP, the parser will decide that the topic understood for the second and final command will be "dog then jump".
His proposal to mimic the answering it that action’s grammar is interesting, but, as he notes, it doesn’t work by default. The reason is that the answering it that action (aka ##Answer in I6) gets special treatment within ParseToken__():
TOPIC_TOKEN:
consult_from = wn;
if ((line_ttype-->(token_n+1) ~= PREPOSITION_TT) &&
(line_token-->(token_n+1) ~= ENDIT_TOKEN)) {
RunTimeProblem(RTP_TEXTTOKENTOOHARD);
return GPR_PREPOSITION;
}
do o = NextWordStopped();
until (o == -1 || PrepositionChain(o, token_n+1) ~= -1);
wn--;
consult_words = wn-consult_from;
if (consult_words == 0) return GPR_FAIL;
if (action_to_be == ##Ask or ##Answer or ##Tell) { ! <--- HERE
o = wn; wn = consult_from; parsed_number = NextWord();
wn = o; return 1;
}
if (o==-1 && (line_ttype-->(token_n+1) == PREPOSITION_TT))
return GPR_FAIL; ! don't infer if required preposition is absent
return GPR_PREPOSITION;
It’s possible to set up the abbreviated asking action in the manner that Draconis suggested:
Abbreviated asking is an action applying to one thing and one topic. Understand "ask [text] of [someone]" or "ask about [text] of [someone]" as abbreviated asking (with nouns reversed).
Understand the command "a" as "ask".
Carry out abbreviated asking:
try asking noun about the topic understood.
and to also modify the special case code in ParseToken__() to include abbreviated asking:
...
if (action_to_be == ##Ask or ##Answer or ##Tell or (+ abbreviated asking action +) ) { ! <--- HERE
o = wn; wn = consult_from; parsed_number = NextWord();
wn = o; return 1;
}
...
but there are some drawbacks:
>A DOG
Whom do you want to a that of?
>ALICE
Alice makes a few pithy comments about dog.
>A DOG
Whom do you want to a that of?
The verb word of "a" is used in the partial command, which can be addressed elsewhere with I6 tinkering if desired. The default prompt does not list candidates for disambiguation as desired. More problematic is that the grammar line now demands a noun so one must be specified to the parser in order to satisfactorily complete the grammar line. A rule for supplying a missing noun can’t help because it’s illegal to specify a reversed grammar line without including two parameters – as the Problem Message that you get states: “[Y]ou can’t use a ‘reversed’ action when you supply fewer than two values for it to apply to, since reversal is the process of exchanging them.”
I did finally get this to work as desired without using an after reading a command text substitution… by using a GPR-based text substitution, which has the advantage of only making changes when the input positively matches the desired grammar as well as that of letting the parser deal with multiple command processing (though still suffering from the run-on topic problem).
An interesting problem. Thank you for asking it; I found some new routes through the parser maze while pondering it.