Hi again. I’m new to this so apologies if I’m coming off as clueless or pushy.
I’m wondering what, if any, next steps there are to advocate for this. Should I
share the code? Given what I mentioned in the responses about using one
variable or using a new `destructure`, is there still disagreement?
Thanks!
Matt F
From: <elixir-lang-core@googlegroups.com> on behalf of Sabiwara Yukichi
<sabiw...@gmail.com>
Reply-To: "elixir-lang-core@googlegroups.com"
<elixir-lang-core@googlegroups.com>
Date: Tuesday, December 13, 2022 at 6:55 PM
To: "elixir-lang-core@googlegroups.com" <elixir-lang-core@googlegroups.com>
Subject: [EXTERNAL] Re: [elixir-core:11213] [proposal] Use patterns to filter
data (good for pipes)
This email came from a source outside of CoverMyMeds. Use caution when clicking
on links or replying with confidential information.
________________________________
This is an interesting idea, but maybe `then/2` (or case/2 if you're fine
piping in it) could already cover these cases quite well (equivalent to your
pattern_filter! function):
"$3.45" |> then(fn "$" <> money -> money end) |> String.to_float()
"$3.45" |> case do "$" <> money -> money end |> String.to_float()
The non-raising alternative might be slightly more verbose because you need a
second clause. But most of the time (like your money example), the next step of
the pipe might fail on nil anyway. Or maybe a with/1 pipeline might work better
than the pipe operator if you want a succession of happy-path matches?
If we move forward, it might be better to explicitly declare the returned
expression, not just infer it from dangling variables: it isn't obvious what
should `{a, b}` or `{a, b, a}` return. Something like:
{1, 2, 1} |> pattern_filter(b <- {a, b, a})
Le mer. 14 déc. 2022 à 05:50, 'Matt Farabaugh' via elixir-lang-core
<elixir-lang-core@googlegroups.com<mailto:elixir-lang-core@googlegroups.com>> a
écrit :
All,
I wrote a macro which allows for using a pattern to essentially extract a value
from a data structure:
@doc """
Filter a value out of data using a pattern with one variable. Returns a default
value
if no match. Raises if pattern contains no variables or more than one variable.
## Examples
iex> "$3.45" |> PatternHelpers.pattern_filter("$" <> money) |> String.to_float()
3.45
iex> {1,2,3} |> PatternHelpers.pattern_filter({1,_,a})
3
iex> %{a: 1, b: 2} |> PatternHelpers.pattern_filter(%{a: 9, b: b})
nil
iex> %{a: 1, b: 2} |> PatternHelpers.pattern_filter(%{a: 9, b: b}, "???")
"???"
"""
And an unsafe version:
@doc """
See `pattern_filter/3`. Raises if no match.
## Examples
iex> {1,2,3} |> PatternHelpers.pattern_filter!({9,_,b})
** (MatchError) no match of right hand side value: {1, 2, 3}
"""
This is my first proposal. Please let me know if this idea is worth some
attention, and how I might better do my part to present it. I have code
obviously but I'm not sure this is the place for it.
Thanks,
Matt F
--
You received this message because you are subscribed to the Google Groups
"elixir-lang-core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
elixir-lang-core+unsubscr...@googlegroups.com<mailto:elixir-lang-core+unsubscr...@googlegroups.com>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/elixir-lang-core/4b65083e-6c36-4519-a0ed-fa2da8b61a9bn%40googlegroups.com<https://urldefense.com/v3/__https:/groups.google.com/d/msgid/elixir-lang-core/4b65083e-6c36-4519-a0ed-fa2da8b61a9bn*40googlegroups.com?utm_medium=email&utm_source=footer__;JQ!!LBRzLL-rxcoG!soAu7_j204hUseqlxMsemQMOhOz0yO8WygSZdV2t7WGq5iDQfDh-prkOc8PkTmo4vz08vKeE_ZmAZ19k2vMrPomauA$>.
--
You received this message because you are subscribed to the Google Groups
"elixir-lang-core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
elixir-lang-core+unsubscr...@googlegroups.com<mailto:elixir-lang-core+unsubscr...@googlegroups.com>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/elixir-lang-core/CANnyohYy8hRvu2WD%2BMUEzWS2SxoA8eYk9PETOe8jGxr2tiuW%2BA%40mail.gmail.com<https://urldefense.com/v3/__https:/groups.google.com/d/msgid/elixir-lang-core/CANnyohYy8hRvu2WD*2BMUEzWS2SxoA8eYk9PETOe8jGxr2tiuW*2BA*40mail.gmail.com?utm_medium=email&utm_source=footer__;JSUl!!LBRzLL-rxcoG!soAu7_j204hUseqlxMsemQMOhOz0yO8WygSZdV2t7WGq5iDQfDh-prkOc8PkTmo4vz08vKeE_ZmAZ19k2vMQT4CMDA$>.
This electronic transmission is confidential and intended solely for the
addressee(s). If you are not an intended addressee, do not disclose, copy or
take any other action in reliance on this transmission. If you have received
this transmission in error, please delete it from your system and notify
CoverMyMeds LLC at priv...@covermymeds.com. Thank you.
--
You received this message because you are subscribed to the Google Groups
"elixir-lang-core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to elixir-lang-core+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/elixir-lang-core/53A15DB8-B2E6-409D-98DB-B7E92A0D0116%40covermymeds.com.
