andre
Effective Haskell: Chapter 10 - directorySummaryWithMetrics (B9 - PDF version)
On p.386, we have the final version of directorySummaryWithMetrics.
When running the code, we see the histogram results with empty characters.
It looks like this
Histogram Data:
: 9091
: 59
: 23
: 1
: 2
: 59
: 12900
: 643147
: 20
: 22
: 563
: 6
: 666771
!: 1476
": 137317
#: 7367
...
The non-printable characters do not display. You can see the empty fields above ASCII value 20 (a total of 666771 spaces here).
Here are the last few lines of the function:
histogram <- readIORef histogramRef
putStrLn "Histogram Data:"
for_ (Map.toList histogram) $ \(letter, count) ->
putStrLn $ printf " %c: %d" letter count
displayMetrics metrics
I suggest to add a check using isControl.
import qualified Data.Char as Char (isControl)
...
histogram <- readIORef histogramRef
putStrLn "\n\nHistogram Data:" -- Added "\n\n"
for_ (Map.toList histogram) $ \(letter, count) ->
if Char.isControl letter then -- Added if .. then ...
putStrLn $ printf " %d: %d" letter count
else
putStrLn $ printf " %c: %d" letter count
displayMetrics metrics
–
Andre
Popular Pragmatic Bookshelf topics
This test is broken right out of the box…
— FAIL: TestAgent (7.82s)
agent_test.go:77:
Error Trace: agent_test.go:77
agent_test.go:...
New
page 37
ANTLRInputStream input = new ANTLRInputStream(is);
as of ANTLR 4 .8 should be:
CharStream stream = CharStreams.fromStream(i...
New
Hi Brian,
Looks like the api for tinydb has changed a little. Noticed while working on chapter 7 that the .purge() call to the db throws...
New
Title: Web Development with Clojure, Third Edition - migrations/create not working: p159
When I execute the command:
user=> (create-...
New
Hi,
build fails on:
bracket-lib = “~0.8.1”
when running on Mac Mini M1 Rust version 1.5.0:
Compiling winit v0.22.2
error[E0308]: mi...
New
Hi @venkats,
It has been mentioned in the description of ‘Supervisory Job’ title that 2 things as mentioned below result in the same eff...
New
I’m new to Rust and am using this book to learn more as well as to feed my interest in game dev. I’ve just finished the flappy dragon exa...
New
This is as much a suggestion as a question, as a note for others.
Locally the SGP30 wasn’t available, so I ordered a SGP40. On page 53, ...
New
“The ProductLive.Index template calls a helper function, live_component/3, that in turn calls on the modal component. ”
Excerpt From: Br...
New
I’m not quite sure what’s going on here, but I’m unable to have to containers successfully complete the Readiness/Liveness checks. I’m im...
New
Other popular topics
You might be thinking we should just ask who’s not using VSCode :joy: however there are some new additions in the space that might give V...
New
New
Just done a fresh install of macOS Big Sur and on installing Erlang I am getting:
asdf install erlang 23.1.2
Configure failed.
checking ...
New
The V Programming Language
Simple language for building maintainable programs
V is already mentioned couple of times in the forum, but I...
New
Crystal recently reached version 1. I had been following it for awhile but never got to really learn it. Most languages I picked up out o...
New
Think Again 50% Off Sale »
The theme of this sale is new perspectives on familiar topics.
Enter coupon code ThinkAgain2021 at checkout t...
New
Biggest jackpot ever apparently! :upside_down_face:
I don’t (usually) gamble/play the lottery, but working on a program to predict the...
New
Hi folks,
I don’t know if I saw this here but, here’s a new programming language, called Roc
Reminds me a bit of Elm and thus Haskell. ...
New
I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...
New
Author Spotlight
Erin Dees
@undees
Welcome to our new author spotlight! We had the pleasure of chatting with Erin Dees, co-author of ...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /ruby
- /wasm
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /emacs
- /haskell
- /java
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /flutter
- /elm
- /vscode
- /ash
- /opensuse
- /html
- /centos
- /deepseek
- /php
- /zig
- /scala
- /sublime-text
- /lisp
- /textmate
- /react-native
- /debian
- /nixos
- /agda
- /kubuntu
- /arch-linux
- /django
- /deno
- /nodejs
- /revery
- /ubuntu
- /manjaro
- /spring
- /diversity
- /lua
- /julia
- /c
- /markdown








