
Ask HN: Developers, what is the last significant thing you learned? - kamyarg
And when did you learn it?<p>Inspired by: https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=23768054
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mindcrime
I just (in the last month or so) learned how to expose the Docker daemon to
code running inside a container, so you can create a "container controlling
container." This works out really nicely for something I've been working on,
which involves running smoke-tests inside a container. This way, the tests can
programmatically request a container instance of the system under test, and
then destroy it, without the need for any sort of coordinator code running one
level higher.

I've also recently (last couple of months) learned just enough Common Lisp to
feel like I am close to "turning the corner" and starting to grok Lisp. If I
keep at it, I think I'll be at a place where I could write something
meaningful in Lisp before much longer. This feels significant to me, as "learn
Lisp" has been on my "to get around to one day" list for about 20 years now.

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m0ck
When writing unit/integration tests and they fail, consider possibility the
test is wrong.

Yesterday I spent two hours researching UUID mappings in H2 and PostgreSQL and
trying various combinations of annotations just to find out that I
accidentally deleted last character of the hardcoded "expected" result.

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medymed
In Haskell you can generate an infinite list of all integers starting from 1
with [1..]

This is both very succinct but for best use also requires a sufficient
understanding of what goes on in the backend, which is true for many features
of the language and isn’t always encouraging for uptake. Syntactical elegance
and efficiency sometimes comes at a cost of high information/context overhead.

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lanecwagner
While developing [https://classroom.qvault.io](https://classroom.qvault.io)
I've been learning that I forget how not obvious literally everything about
coding is.

In the first course I had feedback like, "I didn't understand code starts at
the top and goes down"

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kamyarg
Some items I can recall:

\- using CLoader for YAML loading in Python is x10 faster. (Last weekend)

\- Chrome DEV Tools has an option to simulate different network speeds, really
useful if you are developing for the developing work when cellular speed can
be very low. (~1 year ago)

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HelloFellowDevs
I've just recently committed myself to take Javascript seriously and more than
a language that can work with frameworks.

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giantg2
The last useful thing I learnt is the company always wins and you are worth
nothing.

