[Python-ideas] Ruby-style Blocks in Python Idea

[Greg Ewing]

Jim Jewett wrote:

> I'm not convinced, because I've seen so many times when a lambda
> actually is crucial to the bug.

I think this is just a special case of a more general
problem, that a line number is not always a sufficiently
fine-grained piece of information when you're trying to
pinpoint an error.

You can get the same thing even when lambdas are not
involved. It's particularly bad when an expression spans
more than one line, because CPython currently doesn't even
tell you the line containing the error, but the one where
the whole statement started.

Ideally, the traceback would show you not just the exact
line, but the exact *token* where the error occurred. The
technology exists to do this, it's just a matter of deciding
to incorporate it into Python.

-- 
Greg