Method emit_and_reset_fail_pop

crates/codegen/src/compile.rs:5949–5967

Emits the necessary POP instructions for all failure targets in the pattern context, then resets the fail_pop vector.

(&mut self, pc: &mut PatternContext)

    /// Emits the necessary POP instructions for all failure targets in the pattern context,
    /// then resets the fail_pop vector.
    fn emit_and_reset_fail_pop(&mut self, pc: &mut PatternContext) -> CompileResult<()> {
        // If the fail_pop vector is empty, nothing needs to be done.
        if pc.fail_pop.is_empty() {
            debug_assert!(pc.fail_pop.is_empty());
            return Ok(());
        }
        // Iterate over the fail_pop vector in reverse order, skipping the first label.
        for &label in pc.fail_pop.iter().skip(1).rev() {
            self.switch_to_block(label);
            // Emit the POP instruction.
            emit!(self, Instruction::PopTop);
        }
        // Finally, use the first label.
        self.switch_to_block(pc.fail_pop[0]);
        pc.fail_pop.clear();
        // Free the memory used by the vector.
        pc.fail_pop.shrink_to_fit();
        Ok(())
    }

    /// Duplicate the effect of Python 3.10's ROT_* instructions using SWAPs.
    fn pattern_helper_rotate(&mut self, mut count: usize) -> CompileResult<()> {