(->> ["language" "clojure" "username" "john"] (partition 2) (reduce (fn [m [k v]] (assoc m k v)) {})) ;; => {"language" "clojure", "username" "john"}
27 January 2021
Mr Haki has a Java Joy article about transforming a stream of strings into a map using functional Java. I’m having a bit of trouble embracing it enthusiastically, since each example is 81 lines of Java code and a pointy pile of type declarations!
I dashed out the same functionality in 4 lines of Clojure, and I can understand it a whole lot easier. I’m not even sure this is the fewest forms, but it’s still nicer.
(->> ["language" "clojure" "username" "john"] (partition 2) (reduce (fn [m [k v]] (assoc m k v)) {})) ;; => {"language" "clojure", "username" "john"}
Written with Clojure 1.10.2.
02 November 2020
I took the update to PopOS 20.10,
and my Overtone setup stopped working.
When I’d try to boot up
the internal SuperCollider server
from Emacs or from the leiningen repl
on my music projects
which all (:require [overtone.live :refer :all])
,
get an error in native libraries.
I could also try to start the server
with (boot-internal-server)
or (boot-external-server)
,
but it gives the same error.
--> Booting internal SuperCollider server... Cannot read socket fd = 107 err = Success CheckRes error Could not read result type = 22 Client name = Overtone conflits with another running client Cannot connect to the server JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for -1, skipping unlock JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock could not initialize audio. # # A fatal error has been detected by the Java Runtime Environment: # # SIGSEGV (0xb) at pc=0x00007f5eec0e9ba7, pid=30517, tid=30605 # # JRE version: OpenJDK Runtime Environment AdoptOpenJDK (15.0.1+9) (build 15.0.1+9) # Java VM: OpenJDK 64-Bit Server VM AdoptOpenJDK (15.0.1+9, mixed mode, sharing, tiered, compressed oops, g1 gc, linux-amd64) # Problematic frame: # C [libscsynth.so.1+0x63ba7] World_WaitForQuit+0x7 # # No core dump will be written. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again # # An error report file with more information is saved as: # /home/john/workspace/music/hs_err_pid30517.log --> Connecting to internal SuperCollider server... [thread 30576 also had an error] # # If you would like to submit a bug report, please visit: # https://github.com/AdoptOpenJDK/openjdk-support/issues # The crash happened outside the Java Virtual Machine in native code. # See problematic frame for where to report the bug. #
Since it can no longer start the server internally
from within Overtone,
I start the server manually.
I wrapped a script around the start up,
so I can set the environment variables
for configuring jack
and starting up the synth:
#!/bin/sh # automatically connect up jack ports export SC_JACK_DEFAULT_INPUTS="system:capture_1,system:capture_2" export SC_JACK_DEFAULT_OUTPUTS="system:playback_1,system:playback_2" scsynth -u 57110
To get Overtone going again,
I disabled the automatic boot
of the server within Overtone
by switching all the requires
in each file
from overtone.live
to overtone.core
,
and I connect
to that external server
from my REPL manually
with (connect-external-server)
before doing anything else.
Finally,
Overtone was consistently
failing to find my MIDI keyboard.
When things were working
well enough a couple months ago,
it still had required
a little dance of killing off jackd
and restarting Overtone,
since something had been
tying up the MIDI interface.
This workaround was no longer adequate,
since scsynth
and jackd
needed to already be started.
I disabled MIDI connection in jackd
by removing the -Xseq
option
from my ~/.jackdrc
.
I’m back in business,
and it’s probably more robust
with these manual steps now.
I think I’m also seeing
some other odd little things working
with the external server
that didn’t previously,
like using (mouse-x)
for reading mouse positions into the synth values.
The built-in piano synth is also
working where it hadn’t previously.
Update 2021-02-13:
I had lost the ability
to send desktop audio (pulseaudio)
through to the Jack Sink
with this setup,
so I figured out
to start qjackctl
before my supercollider.sh
.
That gets the Jack Sink
available again to pulseaudio
and the desktop sound menu.
21 October 2020
I’ve occasionally been using a SSH session from my Pixel phones for years to login to my servers and write Clojure code in Emacs. I’d often run into an issue where I find myself having a weird time switching between NORMAL and INSERT modes when I’d hit ESCAPE quickly and try to move the cursor.
Googling my random problems
is a favorite pastime,
and I’ve finally stumbled
upon an article about
tmux and vim escape key.
I learned
that it’s probably been tmux
sporadically eating my ESCAPE key,
so I’ve tried disabling the built-in delay
by adding to my
.tmux.conf
:
set -g -s escape-time 0
11 May 2020
I saw a puzzle pop up on Facebook a couple weeks ago, and it looked like a fun exercise for core.logic, since the puzzle simply requires keeping track of some constraints and reconciling them to one answer.
I had previously tinkered with the core.logic primer and I referred back to it to complete this little puzzle. I had originally coded some more complete rules about exclusion of some values which could have been implied by the puzzle, but I found they could be dropped and still get down to one answer. I started from the entire problem space of all digits and added the constraints to watch and verify each constraint’s effects.
(ns scratch.2020-05 (:require [clojure.core.logic :as l])) (l/run* [a b c] ;; all digits 0-9 (l/membero a (range 10)) (l/membero b (range 10)) (l/membero c (range 10)) ;; 6 8 2 one digit is right and in its right place (l/conde [(l/== a 6)] [(l/== b 8)] [(l/== c 2)]) ;; 6 1 4 one digit is right but in the wrong place (l/conde [(l/membero a [1 4])] [(l/membero b [6 4])] [(l/membero c [6 1])]) ;; 206 2 digits are right, but both are in the wrong place (l/conde [(l/membero a [0 6]) (l/membero b [2 6]) (l/membero c (remove #{2 0 6} (range 10)))] [(l/membero a [0 6]) (l/membero c [2 0]) (l/membero b (remove #{2 0 6} (range 10)))] [(l/membero b [2 6]) (l/membero c [2 0]) (l/membero a (remove #{2 0 6} (range 10)))] ) ;; 3 8 0 one digit is right but in the wrong place (l/conde [(l/membero a [8 0])] [(l/membero b [3 0])] [(l/membero c [3 8])]) ;; 7 3 8 all the digits are wrong (l/membero a (remove #{7 3 8} (range 10))) (l/membero b (remove #{7 3 8} (range 10))) (l/membero c (remove #{7 3 8} (range 10)))) ;; => ([0 4 2])