kbnf-syntax 0.5.3

An internal syntax crate for kbnf crate
Documentation 
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use crate::{
    node::{Alternation, OperatorFlattenedNode},
    regex::{FiniteStateAutomaton, FiniteStateAutomatonConfig},
    semantic_error::SemanticError,
    InternedStrings,
};

#[allow(clippy::result_large_err)]
pub fn compile_one_regex_string(
    regex_string: &str,
    config: FiniteStateAutomatonConfig,
) -> Result<FiniteStateAutomaton, SemanticError> {
    let regex: Result<FiniteStateAutomaton, SemanticError> = match config {
        FiniteStateAutomatonConfig::Dfa(ref config) => {
            kbnf_regex_automata::dfa::dense::Builder::new()
                .configure(config.clone())
                .build(regex_string)
                .map(FiniteStateAutomaton::Dfa)
                .map_err(SemanticError::DfaRegexBuildError)
        }
    };
    regex
}

pub fn from_terminals_to_regex_string(
    terminals: &[Alternation],
    interned_strings: &InternedStrings,
) -> String {
    let regex = terminals
        .iter()
        .map(|x| x.concatenations.first().unwrap())
        .map(|x| match x {
            OperatorFlattenedNode::Terminal(x) => x,
            _ => unreachable!(),
        })
        .map(|x| regex_lite::escape(interned_strings.terminals.resolve(*x).unwrap()))
        .collect::<Vec<_>>()
        .join("|");
    format!(r"\A(?:{})\z", regex)
}