Function libreda_lefdef::lef_parser::read_step_pattern

fn read_step_pattern<I>(
    tk: &mut Tokenized<I, LefDefLexer>
) -> Result<StepPattern, LefDefParseError>where
    I: Iterator<Item = char> + PeekingNext,

Read a step pattern (repetition). Expects a “DO” keyword at the beginning.