Basics of Scala
Descrition del contenete del págine
Conversion de old BASIC-programas a Scala por aprender lu elementari de ti-ci lingue.
Etiquettes:
3D Plot
/*
3D Plot
Original version in BASIC:
Creative Computing (Morristown, New Jersey, USA), ca. 1980.
This version in Scala:
Copyright (c) 2023, Marcos Cruz (programandala.net)
SPDX-License-Identifier: Fair
Written in 2023-08, 2023-09.
Last modified: 20231103T2352+0100.
*/
def home() =
print("\u001B[H")
def clear() =
print("\u001B[2J")
home()
def showCredits() =
println("3D Plot\n")
println("Original version in BASIC:")
println(" Creative computing (Morristown, New Jersey, USA), ca. 1980.\n")
println("This version in Scala:")
println(" Copyright (c) 2023, Marcos Cruz (programandala.net)")
println(" SPDX-License-Identifier: Fair\n")
println("Press any key to start the program.")
io.StdIn.readLine("")
def a(z: Double): Double =
30 * math.exp(-z * z / 100)
def draw() =
val width = 56
val space = ' '
val dot = '*'
var line = new Array[Char](width)
var l = 0
var y1 = 0
var z = 0
var x = -30.0
while x <= 30 do
line = Array.fill(width){space}
l = 0
y1 = 5 * (math.sqrt(900 - x * x) / 5).toInt
for y <- y1 to -y1 by -5 do
z = (25 + a(math.sqrt(x * x + (y * y)))-0.7 * y).toInt
if z > l then
l = z
line(z) = dot
for pos <- 0 until width do
print(line(pos))
println()
x += 1.5
@main def main() =
clear()
showCredits()
clear()
draw()
Bagels
/*
Bagels
Original version in BASIC:
D. Resek, P. Rowe, 1978.
Creative Computing (Morristown, New Jersey, USA), 1978.
This version in Scala:
Copyright (c) 2023, Marcos Cruz (programandala.net)
SPDX-License-Identifier: Fair
Written in 2023-09/10, 2023-11.
Last modified: 20231104T0112+0100.
*/
// Move the cursor to the home position.
def home() =
print("\u001B[H")
// Clear the screen and move the cursor to the home position.
def clear() =
print("\u001B[2J")
home()
// Print the given prompt and wait until the user enters an empty string.
def pressEnter(prompt : String) =
var ok = false
while !ok do
ok = io.StdIn.readLine(prompt) == ""
end while
def printTitle() =
clear()
println("Bagels")
println("Number guessing game\n")
// Clear the screen, display the credits and wait for a keypress.
def printCredits() =
printTitle()
println("Original source unknown but suspected to be:")
println(" Lawrence Hall of Science, U.C. Berkely.\n")
println("Original version in BASIC:")
println(" D. Resek, P. Rowe, 1978.")
println(" Creative computing (Morristown, New Jersey, USA), 1978.\n")
println("This version in Scala:")
println(" Copyright (c) 2023, Marcos Cruz (programandala.net)")
println(" SPDX-License-Identifier: Fair\n")
pressEnter("Press Enter to read the instructions. ")
// Clear the screen, print the instructions and wait for a keypress.
def printInstructions() =
printTitle()
println("I am thinking of a three-digit number that has no two digits the same.")
println("Try to guess it and I will give you clues as follows:\n")
println(" PICO - one digit correct but in the wrong position")
println(" FERMI - one digit correct and in the right position")
println(" BAGELS - no digits correct")
pressEnter("\nPress Enter to start. ")
val Digits = 3
// Return three random digits.
def random() : Array[Int] =
val randomDigit = new Array[Int](Digits)
var digit = 0
for i <- 0 until Digits do
var validDigit = false
while !validDigit do
digit = util.Random.nextInt(10)
validDigit = !randomDigit.contains(digit)
end while
randomDigit(i) = digit
end for
randomDigit
// Prints the given prompt, waits until the user enters a valid integer and
// returns it.
def getNumber(prompt : String) : Int =
var number = 0
var ok = false
while !ok do
try
number = io.StdIn.readLine(prompt).trim.toInt
ok = true
catch
case _ => println("Invalid number.")
end while
number
// Prompts the user to enter a command and returns it trimmed.
def getString(prompt : String = "> ") : String =
io.StdIn.readLine(prompt).trim
// Return `true` if any of the elements of the given string is repeated;
// otherwise return `false`.
def isAnyRepeated(s: String) : Boolean =
s.size != s.toSet.size
def containsOnlyDigits(s: String) : Boolean =
var ok = true
s.foreach(char => ok = ok && char.toChar.isDigit)
ok
// Print the given prompt and get a three-digit number from the user.
def input(prompt : String) : Array[Int] =
val ASCII_0 = 48
val userDigit = new Array[Int](Digits)
var inputString = ""
var done = false
while !done do
inputString = getString(prompt)
if inputString.size != Digits then
println(s"Remember it's a ${Digits}-digit number.")
else
if containsOnlyDigits(inputString) then
if isAnyRepeated(inputString) then
println("Remember my number has no two digits the same.")
else
done = true
end if
else
println("What?")
end if
end if
end while
for i <- 0 until Digits do
userDigit(i) = inputString(i).asDigit
end for
userDigit
// Return `true` if the given string is "yes" or a synonym.
def isYes(answer : String) : Boolean =
Array("ok", "yeah", "yes", "y").contains(answer)
// Return `true` if the given string is "no" or a synonym.
def isNo(answer : String) : Boolean =
Array("no", "nope", "n").contains(answer)
// Print the given prompt, wait until the user enters a valid yes/no
// string, and return `true` for "yes" or `false` for "no".
def yes(prompt : String) : Boolean =
var answer = ""
while !(isYes(answer) || isNo(answer)) do
answer = getString(prompt)
isYes(answer)
// Init and run the game loop.
def play() =
val TRIES = 20
var score = 0
var playing = true
var userNumber = new Array[Int](Digits)
while playing do
clear()
var computerNumber = random()
println("O.K. I have a number in mind.")
var fermi = 0
var pico = 0
var guess = 1 // counter
while fermi != Digits && guess <= TRIES do
userNumber = input(s"Guess #${guess}: ")
fermi = 0
pico = 0
for i <- 0 until Digits do
for j <- 0 until Digits do
if computerNumber(i) == userNumber(j) then
if i == j then
fermi += 1
else
pico += 1
end if
end if
end for
end for
print("PICO ".repeat(pico))
print("FERMI ".repeat(fermi))
if pico + fermi == 0 then
print("BAGELS")
end if
println()
guess += 1
end while
if fermi == Digits then
println("You got it!!!")
score += 1
else
println("Oh well.")
print(s"That's $TRIES guesses. My number was ")
computerNumber.foreach(print)
println(".")
end if
if !yes("Play again? ") then
playing = false
end if
end while // play loop
if score != 0 then
println(s"A ${score}-point bagels, buff!!")
end if
println("Hope you had fun. Bye.")
@main def main() =
printCredits()
printInstructions()
play()
Bunny
/*
Bunny
Original version in BASIC:
Creative Computing (Morristown, New Jersey, USA), 1978.
This version in Scala:
Copyright (c) 2023, Marcos Cruz (programandala.net)
SPDX-License-Identifier: Fair
Written in 2023-08, 2023-09.
Last modified: 20231209T2009+0100.
*/
// Move the cursor to the top left position of the terminal.
def home() =
print("\u001B[H")
// Clear the terminal and move the cursor to the top left position.
def clearScreen() =
print("\u001B[2J")
home()
// Clear the screen, print the credits and wait for the Enter key.
def printCredits() =
clearScreen()
println("Bunny\n")
println("Original version in BASIC:")
println(" Creative Computing (Morristown, New Jersey, USA), 1978.\n")
println("This version in Scala:")
println(" Copyright (c) 2023, Marcos Cruz (programandala.net)")
println(" SPDX-License-Identifier: Fair\n")
println("Press Enter to start the program.")
io.StdIn.readLine("")
val Width = 53
var line = new Array[Int](Width) // buffer
// Clear the line buffer with spaces.
def clearLine() =
var column = 0
for column <- 0 until Width do
line(column) = ' '.toInt
val letter = Array('B', 'U', 'N', 'N', 'Y')
var letters = letter.length
val EOL : Int = -1 // end of line identifier
var data : Array[Int] = Array(
1, 2, EOL, 0, 2, 45, 50, EOL, 0, 5, 43, 52, EOL, 0, 7, 41, 52, EOL,
1, 9, 37, 50, EOL, 2, 11, 36, 50, EOL, 3, 13, 34, 49, EOL, 4, 14,
32, 48, EOL, 5, 15, 31, 47, EOL, 6, 16, 30, 45, EOL, 7, 17, 29, 44,
EOL, 8, 19, 28, 43, EOL, 9, 20, 27, 41, EOL, 10, 21, 26, 40, EOL,
11, 22, 25, 38, EOL, 12, 22, 24, 36, EOL, 13, 34, EOL, 14, 33, EOL,
15, 31, EOL, 17, 29, EOL, 18, 27, EOL, 19, 26, EOL, 16, 28, EOL,
13, 30, EOL, 11, 31, EOL, 10, 32, EOL, 8, 33, EOL, 7, 34, EOL, 6,
13, 16, 34, EOL, 5, 12, 16, 35, EOL, 4, 12, 16, 35, EOL, 3, 12, 15,
35, EOL, 2, 35, EOL, 1, 35, EOL, 2, 34, EOL, 3, 34, EOL, 4, 33,
EOL, 6, 33, EOL, 10, 32, 34, 34, EOL, 14, 17, 19, 25, 28, 31, 35,
35, EOL, 15, 19, 23, 30, 36, 36, EOL, 14, 18, 21, 21, 24, 30, 37, 37,
EOL, 13, 18, 23, 29, 33, 38, EOL, 12, 29, 31, 33, EOL, 11, 13, 17,
17, 19, 19, 22, 22, 24, 31, EOL, 10, 11, 17, 18, 22, 22, 24, 24, 29,
29, EOL, 22, 23, 26, 29, EOL, 27, 29, EOL, 28, 29, EOL)
def printLine() =
for i <- line do
print(i.toChar)
println()
var dataIndex = 0
def datum() =
dataIndex += 1
data(dataIndex - 1)
// Draw the graphic out of `data` and `letter`.
def draw() =
clearScreen()
clearLine()
while dataIndex < data.length do
val firstColumn = datum()
if firstColumn == EOL then
printLine()
clearLine()
else
val lastColumn = datum()
for column <- firstColumn to lastColumn do
line(column) = letter(column % letters).toInt
@main def main() =
printCredits()
draw()
Diamond
/*
Diamond
Original version in BASIC:
Example included in Vintage BASIC 1.0.3.
http://www.vintage-basic.net
This version in Scala:
Copyright (c) 2023, Marcos Cruz (programandala.net)
SPDX-License-Identifier: Fair
Written on 2023-08-25.
Last modified: 20231103T2352+0100.
*/
val lines = 17
@main def diamond() =
var i = 1
var j = 1
while i <= lines / 2 + 1 do
j = 1
while j <= (lines + 1) / 2 - i + 1 do
print(" ")
j += 1
j = 1
while j <= i * 2 - 1 do
print("*")
j += 1
println()
i += 1
i = 1
while i <= lines / 2 do
j = 1
while j <= i + 1 do
print(" ")
j += 1
j = 1
while j <= ((lines + 1) / 2 - i) * 2 - 1 do
print("*")
j += 1
println()
i += 1
Math
/*
Math
Original version in BASIC:
Example included in Vintage BASIC 1.0.3.
http://www.vintage-basic.net
This version in Scala:
Copyright (c) 2023, Marcos Cruz (programandala.net)
SPDX-License-Identifier: Fair
Written on 2023-08-26.
Last modified: 20231103T2352+0100.
*/
@main def main() =
print("Enter a number: ")
var n : Float =
try
io.StdIn.readFloat()
catch
case e: NumberFormatException => 0.0
print(s"ABS($n) = math.abs($n) = "); println(math.abs(n))
print(s"ATN($n) = math.atan($n) = "); println(math.atan(n))
print(s"COS($n) = math.cos($n) = "); println(math.cos(n))
print(s"EXP($n) = math.exp($n) = "); println(math.exp(n))
print(s"INT($n) = $n.toInt = "); println(n.toInt)
print(s"LOG($n) = math.log($n) = "); println(math.log(n))
print(s"SGN($n) = math.signum($n) = "); println(math.signum(n))
print(s"SQR($n) = math.sqrt($n) = "); println(math.sqrt(n))
print(s"TAN($n) = math.tan($n) = "); println(math.tan(n))
Mugwump
// Mugwump
//
// Original version in BASIC:
// Written by Bud Valenti's students of Project SOLO (Pittsburg, Pennsylvania, USA).
// Slightly modified by Bob Albrecht of People's Computer Company.
// Published by Creative Computing (Morristown, New Jersey, USA), 1978.
// - https://www.atariarchives.org/basicgames/showpage.php?page=114
// - http://vintage-basic.net/games.html
//
// This version in Scala:
// Copyright (c) 2023, Marcos Cruz (programandala.net)
// SPDX-License-Identifier: Fair
//
// Written in 2023-09, 2023-11.
//
// Last modified: 20231104T0113+0100.
val GridSize = 10
val Turns = 10
val Mugwumps = 4
class Mugwump :
var hidden : Boolean = true
var x : Int = 0
var y : Int = 0
def reveal() =
hidden = false
def init() =
hidden = true
x = util.Random.nextInt(GridSize)
y = util.Random.nextInt(GridSize)
// Moves the cursor to the top left position of the terminal.
def home() =
print("\u001B[H")
// Clears the terminal and moves the cursor to the top left position.
def clear() =
print("\u001B[2J")
home()
// Prompts the user to enter a command and returns it trimmed.
def command(prompt : String = "> ") : String =
io.StdIn.readLine(prompt).trim
// Prints the given prompt, waits until the user enters a valid integer and
// returns it.
def getNumber(prompt : String) : Int =
var number = 0
var ok = false
while !ok do
try
number = command(prompt).toInt
ok = true
catch
case _ => println("Invalid number.")
number
// Prints the given prompt and waits until the user enters an empty string.
def pressEnter(prompt : String) =
var ok = false
while !ok do
ok = io.StdIn.readLine(prompt) == ""
// Returns `true` if the given string is "yes" or a synonym.
def isYes(answer : String) : Boolean =
answer.toLowerCase match
case "ok" => true
case "yeah" => true
case "yes" => true
case "y" => true
case _ => false
// Returns `true` if the given string is "no" or a synonym.
def isNo(answer : String) : Boolean =
answer.toLowerCase match
case "no" => true
case "nope" => true
case "n" => true
case _ => false
// Prints the given prompt, waits until the user enters a valid yes/no
// string, and returns `true` for "yes" or `false` for "no".
def yes(prompt : String) : Boolean =
var answer : String = ""
while !(isYes(answer) || isNo(answer)) do
answer = command(prompt)
isYes(answer)
// Clears the screen, prints the credits and asks the user to press enter.
def printCredits() =
clear()
println("Mugwump\n")
println("Original version in BASIC:")
println(" Written by Bud Valenti's students of Project SOLO (Pittsburg, Pennsylvania, USA).")
println(" Slightly modified by Bob Albrecht of People's Computer Company.")
println(" Published by Creative Computing (Morristown, New Jersey, USA), 1978.")
println(" - https://www.atariarchives.org/basicgames/showpage.php?page=114")
println(" - http://vintage-basic.net/games.html\n")
println("This version in Scala:")
println(" Copyright (c) 2023, Marcos Cruz (programandala.net)")
println(" SPDX-License-Identifier: Fair\n")
pressEnter("Press Enter to read the instructions. ")
// Clears the screen, prints the instructions and asks the user to press enter.
def printInstructions() =
clear()
println("Mugwump\n")
println("The object of this game is to find four mugwumps")
println("hidden on a 10 by 10 grid. Homebase is position 0,0.")
println("Any guess you make must be two numbers with each")
println("number between 0 and 9, inclusive. First number")
println("is distance to right of homebase and second number")
println("is distance above homebase.\n")
print(s"You get ${Turns} tries. After each try, you will see\n")
println("how far you are from each mugwump.\n")
pressEnter("Press Enter to start. ")
// Prints the given prompt, then waits until the user enters a valid coord and
// returns it.
def getCoord(prompt : String) : Int =
var coord : Int = 0
var right = false
while !right do
coord = getNumber(prompt)
if coord < 0 || coord >= GridSize then
print(s"Invalid value ${coord}: not in range [0, ${GridSize - 1}].\n")
else
right = true
coord
// Returns `true` if the given mugwump is hidden in the given coords.
def isHere(m : Mugwump, x : Int, y : Int) : Boolean =
m.hidden && m.x == x && m.y == y
// Returns the distance between the given mugwump and the given coords.
def distance(m : Mugwump, x : Int, y : Int) : Int =
math.sqrt(math.pow((m.x - x), 2) + math.pow((m.y - y), 2)).toInt
// If the given number is greater than 1, this method returns a plural ending
// (default: "s"); otherwise it returns a singular ending (default: an empty
// string).
def plural(n : Int, plural : String = "s", singular : String = "") : String =
if n > 1 then plural else singular
// Prints the mugwumps found in the given coordinates and returns the count.
def foundAt(mugwump : Array[Mugwump], x : Int, y : Int) : Int =
var found : Int = 0
for m <- 0 until Mugwumps do
if isHere(mugwump(m), x, y) then
mugwump(m).reveal()
found += 1
print(s"You have found mugwump ${m}!\n")
end if
end for
found
// Runs the game.
def play() =
var found : Int = 0 // counter
var turn : Int = 0 // counter
var m : Int = 0
var x : Int = 0
var y : Int = 0
var gameOver = false
val mugwump = new Array[Mugwump](Mugwumps)
for m <- 0 until Mugwumps do
mugwump(m) = new Mugwump
while !gameOver do // game
clear()
for m <- 0 until Mugwumps do
mugwump(m).init()
found = 0
turn = 0
while turn < Turns && found < Mugwumps do
turn += 1
print(s"Turn number ${turn}\n\n")
print(s"What is your guess (in range [0, ${GridSize - 1}])?\n")
x = getCoord("Distance right of homebase (x-axis): ")
y = getCoord("Distance above homebase (y-axis): ")
print(s"\nYour guess is ($x, $y).\n")
found += foundAt(mugwump, x, y)
if found < Mugwumps then
for m <- 0 until Mugwumps do
if mugwump(m).hidden then
print(s"You are ${distance(mugwump(m), x, y)} units from mugwump ${m}.\n")
end if
end for
println("")
end if
end while // turns
if found == Mugwumps then
print(s"\nYou got them all in ${turn} turn${plural(turn)}!\n\n")
println("That was fun! let's play again…")
println("Four more mugwumps are now in hiding.")
else
print(s"\nSorry, that's ${Turns} tr${plural(Turns, "ies", "y")}.\n\n")
println("Here is where they're hiding:")
for m <- 0 until Mugwumps do
if mugwump(m).hidden then
print(s"Mugwump $m is at (${mugwump(m).x}, ${mugwump(m).y}).\n")
end if
end for
end if
println("")
gameOver = !yes("Do you want to play again? ")
end while // game
@main def main() =
printCredits()
printInstructions()
play()
Russian Roulette
/*
Russian Roulette
Original version in BASIC:
Creative Computing (Morristown, New Jersey, USA), ca. 1980.
This version in Scala:
Copyright (c) 2023, Marcos Cruz (programandala.net)
SPDX-License-Identifier: Fair
Written in 2023-09.
Last modified: 20231103T2352+0100.
*/
// Move the cursor to the top left position of the terminal.
def home() =
print("\u001B[H")
// Clear the terminal and move the cursor to the top left position.
def clear() =
print("\u001B[2J")
home()
// Prompts the user to enter a command and returns it trimmed.
def command(prompt : String = "> ") : String =
io.StdIn.readLine(prompt).trim
// Prints the given prompt and waits until the user enters an empty string.
def pressEnter(prompt : String) =
var ok = false
while !ok do
ok = io.StdIn.readLine(prompt) == ""
def pressEnterToStart() =
pressEnter("Press Enter to start. ")
def printCredits() =
clear()
println("Russian Roulette\n")
println("Original version in BASIC:")
println(" Creative Computing (Morristown, New Jersey, USA), ca. 1980.\n")
println("This version in Scala:")
println(" Copyright (c) 2023, Marcos Cruz (programandala.net)")
println(" SPDX-License-Identifier: Fair\n")
pressEnterToStart()
def printCommands() =
println("Type 'f' to spin chamber and pull trigger.")
println("Type 'g' to give up, and play again.")
println("Type 'q' to quit.")
def printInstructions() =
clear()
println("Here is a revolver.")
printCommands()
println()
def play() =
var gameOver = false
while !gameOver do // game loop
printInstructions()
var times = 0
var playing = true
while playing do // play loop
command() match
case "f" => // fire
if util.Random.nextInt(100) > 83 then
println("Bang! You're dead!")
println("Condolences will be sent to your relatives.")
playing = false
else
times += 1
if times > 10 then
println("You win!")
println("Let someone else blow his brains out.")
playing = false
else
println("Click.")
case "g" => // give up
println("Chicken!")
playing = false
case "q" => // quit
playing = false
gameOver = true
case _ =>
println("Wrong action.")
printCommands()
end while // play loop
pressEnterToStart()
end while // game loop
@main def main() =
printCredits()
play()
println("Bye!")
Sine Wave
/*
Sine Wave
Original version in BASIC:
Creative Computing (Morristown, New Jersey, USA), ca. 1980.
This version in Scala:
Copyright (c) 2023, Marcos Cruz (programandala.net)
SPDX-License-Identifier: Fair
Written in 2023-08, 2023-09.
Last modified: 20231103T2352+0100.
*/
def home() =
print("\u001B[H")
def clear() =
print("\u001B[2J")
home()
val order = Array("first", "second")
var word = Array("", "")
def getWords() =
clear()
for w <- Seq(0, 1) do
word(w) = io.StdIn.readLine(s"Enter the ${order(w)} word: ")
def showCredits() =
clear()
println("Sine Wave\n")
println("Original version in BASIC:")
println(" Creative Computing (Morristown, New Jersey, USA), ca. 1980.\n")
println("This version in Scala:")
println(" Copyright (c) 2023, Marcos Cruz (programandala.net)")
println(" SPDX-License-Identifier: Fair\n")
println("Press Enter to start the program.")
io.StdIn.readLine("")
def draw() =
clear()
var even = true
var angle = 0.0
while angle <= 40 do
print(" " * (26 + 25 * math.sin(angle)).toInt)
println(word(if even then 0 else 1))
even = !even
angle += 0.25
@main def main() =
showCredits()
getWords()
draw()
Strings
// Strings
//
// Original version in BASIC:
// Example included in Vintage BASIC 1.0.3.
// http://www.vintage-basic.net
//
// This version in Scala:
// Copyright (c) 2023, Marcos Cruz (programandala.net)
// SPDX-License-Identifier: Fair
//
// Written in 2023-09-28/29.
//
// Last modified: 20231209T2008+0100.
// Prompts the user to enter a command and returns it trimmed.
def readString(prompt : String = "") : String =
scala.io.StdIn.readLine(prompt).trim
// Prompts the user to enter an integer and returns it.
def readInteger(prompt : String = "") : Int =
var integer = 0
var ok = false
while !ok do
try
integer = readString(prompt).toInt
ok = true
catch
case _ => println("That wasn't a valid integer.")
integer
@main def main() =
val s = readString("Enter a string: ")
val n = readInteger("Enter an integer: ")
print(s"ASC(\"$s\") --> ")
print(s"\"$s\"(0).toChar.toInt --> ")
println(s"${s(0).toChar.toInt}")
print(s"CHR$$($n) --> ")
print(s"$n.toChar --> ")
println(s"'${n.toChar}'")
print(s"LEFT$$(\"$s\", $n) --> ")
print(s"\"$s\".substring(0, $n.min(\"$s\".size)) --> ")
println(s"\"${s.substring(0, n.min(s.size))}\"")
print(s"MID$$(\"$s\", $n) --> ")
print(s"\"$s\".substring(($n - 1).min(\"$s\".size)) --> ")
println(s"\"${s.substring((n - 1).min(s.size))}\"")
print(s"MID$$(\"$s\", $n, 3) --> ")
print(s"\"$s\".substring(($n - 1).min(\"$s\".size), ($n - 1 + 3).min(\"$s\".size)) --> ")
println(s"\"${s.substring((n - 1).min(s.size), (n - 1 + 3).min(s.size))}\"")
print(s"RIGHT$$(\"$s\", $n) --> ")
print(s"\"$s\".substring((\"$s\".size - $n).max(0)) --> ")
println(s"\"${s.substring((s.size - n).max(0))}\"")
print(s"LEN(\"$s\") --> ")
print(s"\"$s\".size --> ")
println(s.size)
print(s"VAL(\"$s\") --> ")
print(s"try \"$s\".trim.toFloat catch case _ => (0.0) --> ")
println(try s.trim.toFloat catch case _ => (0.0))
print(s"STR$$($n) --> ")
print(s"$n.toString --> ")
println(s"\"${n.toString}\"")
print(s"SPC($n) --> ")
print(s"\" \".repeat($n) --> ")
println(s"\"${" ".repeat(n)}\"")