My recent work has been a bit all over the place, which I suppose is reasonable as the year winds down. I worked on more ambiguity resolution in the Text Parser, and I'm almost done with a big refactor in the Narrative engine.
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| A generated Narrative flow diagram showing an excerpt of a story |
In the Parser I worked on two problems. First came the identification of the pronoun "her" as either an indirect object or a possessive adjective. Other English pronouns have separate forms for these two functions (him/his, them/their, me/my, you/your); the feminine singular just has to go and be annoying that way.
If there's some other determiner between "her" and the following noun, you can assume that "her" is an indirect object; otherwise, if the noun needs a determiner, then "her" has to function as the determiner, as in these examples:
Bring her the book. ("Her" is an indirect object)
Bring her book. ("Her" is an adjective modifying "book")
But what about this sentence?
Bring her flowers and candy.
A bulk noun like "candy" doesn't need a determiner; neither does the plural of a count noun, like "flowers." So we can't assume that "her" is an adjective in this sentence. By default, I think it's more likely to be an indirect object, so that's what I have the Parser assume when processing the sentence in isolation. Additional hints in the sentence can shift this default behavior, though:
Bring her candy to me.
The phrase "to me" already fulfills the function that could otherwise be fulfilled by an indirect object, so its presence pushes "her" into the possessive adjective role.
The other ambiguity I worked on had to do with the connections between verbs joined by a conjunction and a direct object. Consider the following sentences:
I baked and ate the bread.
I ran out and saw the airplane.
In the first sentence, both verbs apply to the single direct object. In the second sentence, "ran" has no object and only "saw" applies to "airplane." So for a sentence with multiple verbs followed by one direct object, we have two possible "flow diagrams":
/-baked-\
I-- -- bread
\---ate--/
/--ran
I--
\--saw--airplane
How to know which one is correct? If the first verb is always transitive (a verb that demands a direct object) then the first structure is the obvious choice. But many verbs can be either transitive or intransitive. It is possible to simply "bake" without specifying what; and there are several things that can be run, such as races and gauntlets. So to properly analyze these sentences, we need to consider the possible relationships between verbs and object.
Fortunately Acuitas already has a semantic memory relationship that is relevant: "can_have_done," which links nouns with actions (verbs) that can typically be done on them. Bread is a thing that can be baked; but one does not run an airplane, generally speaking. So correct interpretations follow if this "commonsense" knowledge is retrieved from the semantic memory and used. If knowledge is lacking, the Parser will assume the second structure, in which only the last verb is connected to the direct object.
The Narrative refactor is more boring, as refactoring always is, but I'm hoping it will enable smoother additions to that module in the future. New facts received in the course of a story or conversation are stored in the narrative scratchboard's "worldstate." When an issue (problem or subgoal) is added, its data structure includes a copy of the facts relevant to the issue: the state that needs to be achieved or avoided, the character goal it's relevant to, and all the inferences that connect them. A big part of tracking meaning and progress through the narrative is keeping track of which of these facts are currently known true, known false, or unknown/hypothetical. And previously, whenever something changed, the Narrative Engine had to go and update both the worldstate *and* the chains of relevant facts in all the issues. I've been working to make the issues exclusively use indirect pointers to facts in the worldstate, so that I only have to update fact status in *one* place. That might not sound like a major change, but ... it is. Updating issues was a big headache, and this should make the code simpler and less error-prone. That also means that transitioning the original cobbled-together code to the new system has been a bit of work. But I hope it'll be worth it.
Until the next cycle,
Jenny
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