Struct cfgrammar::yacc::grammar::SentenceGenerator

pub struct SentenceGenerator<'a, StorageT> { /* fields omitted */ }

A SentenceGenerator can generate minimal sentences for any given rule. e.g. for the grammar:

%start A
%%
A: A B | ;
B: C | D;
C: 'x' B | 'x';
D: 'y' B | 'y' 'z';

the following are valid minimal sentences:

A: []
B: [x]
C: [x]
D: [y, x] or [y, z]

Methods

impl<'a, StorageT: 'static + PrimInt + Unsigned> SentenceGenerator<'a, StorageT> where     usize: AsPrimitive<StorageT>,

pub fn min_sentence_cost(&self, ridx: RIdx<StorageT>) -> u16

What is the cost of a minimal sentence for the rule ridx? Note that, unlike min_sentence, this function does not actually build a sentence and it is thus much faster.

pub fn max_sentence_cost(&self, ridx: RIdx<StorageT>) -> Option<u16>

What is the cost of a maximal sentence for the rule ridx? Rules which can generate sentences of unbounded length return None; rules which can only generate maximal strings of a finite length return a Some(u16).

pub fn min_sentence(&self, ridx: RIdx<StorageT>) -> Vec<TIdx<StorageT>>

Non-deterministically return a minimal sentence from the set of minimal sentences for the rule ridx.

pub fn min_sentences(&self, ridx: RIdx<StorageT>) -> Vec<Vec<TIdx<StorageT>>>

Return (in arbitrary order) all the minimal sentences for the rule ridx.