https://github.com/myuon/funcformat

a simple text-formatting way by QuasiQuotes
https://github.com/myuon/funcformat

Last synced: 23 days ago
JSON representation

a simple text-formatting way by QuasiQuotes

• Host: GitHub
• URL: https://github.com/myuon/funcformat
• Owner: myuon
• License: bsd-3-clause
• Created: 2013-02-07T07:11:02.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-02-23T10:57:01.000Z (over 11 years ago)
• Last Synced: 2023-03-25T12:03:07.719Z (over 1 year ago)
• Language: Haskell
• Homepage:
• Size: 125 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
FuncFormat

======================

Want to format like `string.format` in Python in Haskell program? Use this!

Sample

-----------------

Here is a tiny sample.

```haskell

{-# LANGUAGE QuasiQuotes #-}

{-# LANGUAGE OverloadedStrings #-}

import Text.FuncFormat

import Data.Text

import Control.Lens

-- [format| {_1} |] f (a,b) == pack $ show $ f _1 (a,b)

main = putStrLn $ unpack $ [format| {_1}, {_2}!|] view view ("hello", "world")

-- output: hello, world!

```

I strongly recommend you import `Control.Lens` ([Lens package](http://hackage.haskell.org/package/lens )) so that this `format` function can be easy to handle.

**Be careful!**

Do not forget to declare GHC extensions `{-# LANGUAGE QuasiQuotes #-}` and `{-# LANGUAGE OverloadedStrings #-}` at first line in your .hs file.

How does it works

-----------------

There is only one expression to use this `format`:  

```haskell

[format| {f1} {f2}|] g1 g2 t == pack $ show (f1 g1 t) ++ show (f2 g2 t)

```

`format` returns Text (from [Data.Text](http://hackage.haskell.org/package/text))

Then, if you just want to show the elements of a tuple:  

```haskell

[format| {_1}|] view (1,2)

-- output: 1

```  

(`view` and `_1` come from [Control.Lens.Getter](http://hackage.haskell.org/packages/archive/lens/3.8.5/doc/html/Control-Lens-Getter.html ))

If you want to show the elements of a tuple but after applying some other function:  

```haskell

[format| {_1}!|] (\x (y,z) -> set x y z) ("hello", (10,100))

-- output: (hello,100)!

```

There must be some other way to use `format`. Anyways, this may be helpful when you make a pretty printer by yourself :)