• bearophile (47/47) Jan 18 2015 An interesting library for Scala language (found through Reddit):
• Tobias Pankrath (1/1) Jan 18 2015 What's up with that 'filename syntax?
• bearophile (5/6) Jan 18 2015 I think such little details are not important for this Phobos
• Dmitry Olshansky (16/17) Jan 18 2015 If memory serves right it's Symbol in Scala which is about the same as

"bearophile" <bearophileHUGS lycos.com> writes:

An interesting library for Scala language (found through Reddit):

https://github.com/lihaoyi/Ammonite#ammonite-010

I think this library is interesting for D not for its command 
line usage nor for the details of its syntax (that I think is too 
much succinct), but as an example of things you want to do in a 
handy way with Phobos, as:


// Get the current working directory
val d = cwd

// Copy a file or folder
cp(d/'file, d/'file2)

// Make a folder named "folder"
mkdir! d/'folder

// Rename all .scala files inside the folder d into .java files
ls! d | mv{case r"$x.scala" => s"$x.java"}

// Line-count of all .scala files recursively in d
ls.rec! cwd |? (_.ext == "scala") | read.lines | (_.size) sum

// Find and concatenate all .js files directly in the working 
directory
ls! cwd |? (_.ext == "js") | read |> write! wd/'target/"bundle.js"

// Make a directory
mkdir! cwd/'folder

// Move it
mv(cwd/'folder, cwd/'folder2)

// Copy it; recursive by default
cp(cwd/'folder2, cwd/'folder3)

// List the files in cwd
ls! cwd

// List the files in cwd recursively
ls.rec! cwd

// Remove one of them; recursive by default
rm! cwd/'folder2

// Write a file, if it doesn't exist
write(cwd/'folder2/"data.txt", "I am a cow")

// Write to a file, stomping over anything that exists
write.over(cwd/'folder2/"data.txt", "I am a cow")

// Append to a file
write.append(cwd/'folder2/"data.txt", "I am a cow")

// Read a file as a String
read! cwd/'folder2/"data.txt"

// Read a file as an Iterator[String]
read.lines! cwd/'folder2/"data.txt"

// Read a file as an Array[Byte]
read.bytes! cwd/'folder2/"data.bin"

// Check if a file or folder exists
exists! cwd/'folder2/"data.txt"


Bye,
bearophile

"Tobias Pankrath" <tobias pankrath.net> writes:

What's up with that 'filename syntax?

"bearophile" <bearophileHUGS lycos.com> writes:

Tobias Pankrath:

 What's up with that 'filename syntax?

I think such little details are not important for this Phobos 
thread.

Bye,
bearophile

Dmitry Olshansky <dmitry.olsh gmail.com> writes:

On 18-Jan-2015 17:35, Tobias Pankrath wrote:
 What's up with that 'filename syntax?

If memory serves right it's Symbol in Scala which is about the same as 
string constant. The assumption is that compiler is aware of all symbols 
used in a program and keeps them interned at all times.
http://stackoverflow.com/questions/3554362/purpose-of-scalas-symbol
Differences are minor, I think the snippet tries to show that the 
library supports both.

I guess the code works by having an implicit conversion from String and 
Symbol to some PathSegment type from string and overloading / operator 
for PathSegments. Since there is no / for basic strings Scala as usual 
tries all implicit conversions of arguments to find the proper method.

All of this implicit conversion to some other type on demand may sound 
scary and is very much unlike D's way of extending existing types with 
UFCS. IMHO it's more powerful but more prone to abuse.


-- 
Dmitry Olshansky