Method lower_while

crates/hll-to-ir/src/compiler/compiler/control_flow.rs:488–563

(
        &mut self,
        ir_program: &mut IrProgram,
        cond: &Expression,
        body: &Block,
    )

            lowered.value
        } else {
            self.context.error(format!(
                "failed to lower while condition `{}` (see previous diagnostics for root cause)",
                self.format_expression(cond)
            ));
            IrValue::Bool(false)
        };

        self.set_terminator(IrTerminator::Branch {
            cond: cond_value,
            then_label: body_label.clone(),
            else_label: exit_label.clone(),
        });

        // Loop-carried locals stay in stack slots until COMPILER_QUALITY_PLAN.md.
        self.start_new_block(body_label.0.clone());
        self.loop_labels
            .push((cond_label.clone(), exit_label.clone()));
        self.lower_block(ir_program, body);
        self.loop_labels.pop();
        self.set_terminator(IrTerminator::Jump(cond_label.clone()));

        self.start_new_block(exit_label.0.clone());
    }

    // A `for` loop desugars to a `while` loop, reusing the existing `while`
    // lowering (phi/break/continue) so no new IR forms are needed.
    pub(super) fn lower_for(
        &mut self,
        ir_program: &mut IrProgram,
        var: &str,
        iter: &crate::ast::ForIter,
        body: &Block,
    ) {
        match iter {
            crate::ast::ForIter::Range {
                start,
                end,
                inclusive,
            } => self.lower_for_range(ir_program, var, start, end, *inclusive, body),
            crate::ast::ForIter::Each(seq) => self.lower_for_each(ir_program, var, seq, body),
        }
    }

    // Desugars to a while loop: `end` is evaluated once into a temporary, the
    // compare is `<` (`<=` when inclusive), and the step increments by one.
    fn lower_for_range(
        &mut self,
        ir_program: &mut IrProgram,
        var: &str,
        start: &Expression,
        end: &Expression,
        inclusive: bool,
        body: &Block,
    ) {
        let id = self.for_loop_id;
        self.for_loop_id += 1;
        let end_name = format!("__for_end_{id}");