Function piston_meta::optimize::unique_table_from_select

pub fn unique_table_from_select(
    select: &Select, 
    refs: &[Rule]
) -> ([u8; 256], usize)

Creates a unique table from select rule.

Uses a unique byte rule: A unique byte determines which sub-rule to process.

Returns a table mapping from next byte to sub-rule index, and an index for which the unique byte rule no longer holds.

Supports only up to 255 sub-rules, but this is sufficient for most cases.