Some of these things look really nice. I'm particularly impressed by the tracing macro:

    with trace:
        sum = 0
        for i in range(0, 5):
            sum = sum + 5

prints

    sum = 0
    for i in range(0, 5):
        sum = sum + 5
    range(0, 5) -> [0, 1, 2, 3, 4]
    sum = sum + 5
    sum + 5 -> 5
    sum = sum + 5
    sum + 5 -> 10
    sum = sum + 5
    sum + 5 -> 15
    sum = sum + 5
    sum + 5 -> 20
    sum = sum + 5
    sum + 5 -> 25

This would save a huge amount of boring typing `print(...)` when debugging, and since it's only for debugging you don't even need to have MacroPy as a dependency!

Unfortunately python 3.4 support is not quite ready [0], and attempting to install it with `pip3` just fails.

[0]: https://github.com/lihaoyi/macropy/issues/32