Problem running @main methods with command line arguments

[spamegg1]

Compiler version

3.1.1

Minimized code

// In file echoargs.scala
@main def echo(args: String*) =
  println(args.mkString(" "))

Output

First compile

$ scalac echoargs.scala

Then run the main method:

$ scala echo hello world
echo hello world hello world

Expectation

$ scala echo hello world
hello world

Edit: this was the output using the scala command of 3.0.2

[spamegg1]

Similarly, for this file

// In file repeatword.scala
@main def repeat(word: String, count: Int) =
  println(List.fill(count)(word).mkString(" "))

Output

First compile

$ scalac repeatword.scala

Then run the main method:

$ scala repeat hello 3
Illegal command line after first argument: java.lang.NumberFormatException: For input string: "hello"

However:

$ scala repeat 3
repeat repeat repeat

Expectation

$ scala repeat hello 3
hello hello hello

[som-snytt]

PR is quick tweak. Key phrase from last summer: "MainGenericRunner should work almost ".

If we can go 6 months without using command line args, then maybe we don't need command line args.

[som-snytt]

$ scala echo hello world
echo hello world hello world

Crossword just had clue "hello hello hello, e.g." for "echo".

[spamegg1]

If we can go 6 months without using command line args, then maybe we don't need command line args.

The book told me to do it! (Prog in Scala 5th ed) It's used to show the power of type classes:

How does Scala know how to turn the command line string "3" into
an Int 3 ? It uses a typeclass named FromString ,

[bishabosha]

the scala command was ported from bash to Scala in 3.1.0 - this did work as expected with the scala command of 3.0.2