scala-exercises/scala-exercises

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hobovsky

@hobovsky

You are right. But working with the code locally in IDE can help a lot.

ashkolyar

@ashkolyar

so whats wrong with this

val c = 'a' //unicode for a
val e = '\"'
val f = '\'

"%c".format(c) should be(
"a"
)
"%c".format(e) should be(
"\""
)
"%c".format(f) should be(
"\"
)

it doesn't even compile

hobovsky

@hobovsky

Yup, it does not

Your literals are incorrect

ashkolyar

@ashkolyar

and yet when i do the following in a worksheet

"%c".format('a')
"%c".format('\"')
"%c".format('\')

i get the correct values of

a " and \

the double quote is the one that's probably wrong

but i don't understand what its expecting

hobovsky

@hobovsky

But is this part which does not compile?

Its expecting a valid string literal

Yours is not

ashkolyar

@ashkolyar

and whats a valid string literal for a double quote

"\"""""""""""

"\"" is a valid string literal for double quote is it not

hobovsky

@hobovsky

This one you got ok

ashkolyar

@ashkolyar

which one nothing i try works

hobovsky

@hobovsky

Why wont you add scalatest and recreate tests locally too?

The one for backslash

ashkolyar

@ashkolyar

but the one for double quote iis wrong

hobovsky

@hobovsky

Backslash is a special character, it must be escaped in string literals

ashkolyar

@ashkolyar

and i tried """""""

three double quotes followed by the double quote followed by three more double quotes

doesn't work

hobovsky

@hobovsky

Are you sure thats the one which is wrong?

ashkolyar

@ashkolyar

well its not "a"

its the same as the question aove

hobovsky

@hobovsky

For a double quote, string literal should be "\"" and character literal is '"' or '\"', cant remember which one exactly

ashkolyar

@ashkolyar

i tried that

"\"" doesnt work

hobovsky

@hobovsky

But for backslash, the last one, you got things wrong i think

ashkolyar

@ashkolyar

"\"

with a double \

surrounded by quotes

hobovsky

@hobovsky

Why dont you use markdown, would be easier to read

"\\"

ashkolyar

@ashkolyar

will do

hobovsky

@hobovsky

You just made me to solve it on a mobile and i hate you a bit :)

Also, the answers id expect to be correct, are accepted

Wha are your answers exactly, like you entered them into placeholders?

"a" - first one

"\"" - second

"\\" - third

ashkolyar

@ashkolyar

that is what i entered to get the tick

issuewas with the third

XiaoJinZi

@xiaojinzi3473

re-write IntSet with Type parameter

abstract class Set[A] {
  def incl(a: A): Set[A]
  def contains(a: A): Boolean
}

class NonEmpty[A <% Ordered[A]](elem: A, left: Set[A], right: Set[A]) extends Set[A]{
  def contains(x: A): Boolean = {
    if (x < elem) left contains x
    else if (x > elem) right contains x
    else true
  }

  def incl(x: A): Set[A] = {
    if (x < elem) new NonEmpty[A](elem, left incl x, right)
    else if (x > elem) new NonEmpty[A](elem, left, right incl x)
    else this
  }
}

class Empty[A <% Ordered[A]] extends Set[A] {
  def contains(a: A): Boolean = false
  def incl(a: A): Set[A] = new NonEmpty[A](a, new Empty[A], new Empty[A])
}

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