Class ForInfiniteCounter

mypyc/irbuild/for_helpers.py:1179–1204

Generate optimized IR for a for loop counting from 0 to infinity.

class ForInfiniteCounter(ForGenerator):
    """Generate optimized IR for a for loop counting from 0 to infinity."""

    def init(self) -> None:
        builder = self.builder
        # Create a register to store the state of the loop index and
        # initialize this register along with the loop index to 0.
        zero = Integer(0)
        self.index_reg = builder.maybe_spill_assignable(zero)
        self.index_target: Register | AssignmentTarget = builder.get_assignment_target(self.index)

    def gen_step(self) -> None:
        builder = self.builder
        line = self.line
        # We can safely assume that the integer is short, since we are not going to wrap
        # around a 63-bit integer.
        # NOTE: This would be questionable if short ints could be 32 bits.
        new_val = builder.int_op(
            short_int_rprimitive, builder.read(self.index_reg, line), Integer(1), IntOp.ADD, line
        )
        builder.assign(self.index_reg, new_val, line)

    def begin_body(self) -> None:
        self.builder.assign(
            self.index_target, self.builder.read(self.index_reg, self.line), self.line
        )


class ForEnumerate(ForGenerator):