Object scala.Console
object Console extends AnsiColor
Value Members
final def !=(arg0: Any): Boolean
Test two objects for inequality.
- returns
trueif !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
final def ##(): Int
Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.
- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
final def ==(arg0: Any): Boolean
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
- returns
trueif the receiver object is equivalent to the argument;falseotherwise.
- Definition Classes
- AnyRef → Any
final val BLACK: String("\u001B[30m")
Foreground color for ANSI black
- Definition Classes
- AnsiColor
final val BLACK_B: String("\u001B[40m")
Background color for ANSI black
- Definition Classes
- AnsiColor
final val BLINK: String("\u001B[5m")
ANSI blink
- Definition Classes
- AnsiColor
final val BLUE: String("\u001B[34m")
Foreground color for ANSI blue
- Definition Classes
- AnsiColor
final val BLUE_B: String("\u001B[44m")
Background color for ANSI blue
- Definition Classes
- AnsiColor
final val BOLD: String("\u001B[1m")
ANSI bold
- Definition Classes
- AnsiColor
final val CYAN: String("\u001B[36m")
Foreground color for ANSI cyan
- Definition Classes
- AnsiColor
final val CYAN_B: String("\u001B[46m")
Background color for ANSI cyan
- Definition Classes
- AnsiColor
final val GREEN: String("\u001B[32m")
Foreground color for ANSI green
- Definition Classes
- AnsiColor
final val GREEN_B: String("\u001B[42m")
Background color for ANSI green
- Definition Classes
- AnsiColor
final val INVISIBLE: String("\u001B[8m")
ANSI invisible
- Definition Classes
- AnsiColor
final val MAGENTA: String("\u001B[35m")
Foreground color for ANSI magenta
- Definition Classes
- AnsiColor
final val MAGENTA_B: String("\u001B[45m")
Background color for ANSI magenta
- Definition Classes
- AnsiColor
final val RED: String("\u001B[31m")
Foreground color for ANSI red
- Definition Classes
- AnsiColor
final val RED_B: String("\u001B[41m")
Background color for ANSI red
- Definition Classes
- AnsiColor
final val RESET: String("\u001B[0m")
Reset ANSI styles
- Definition Classes
- AnsiColor
final val REVERSED: String("\u001B[7m")
ANSI reversed
- Definition Classes
- AnsiColor
final val UNDERLINED: String("\u001B[4m")
ANSI underlines
- Definition Classes
- AnsiColor
final val WHITE: String("\u001B[37m")
Foreground color for ANSI white
- Definition Classes
- AnsiColor
final val WHITE_B: String("\u001B[47m")
Background color for ANSI white
- Definition Classes
- AnsiColor
final val YELLOW: String("\u001B[33m")
Foreground color for ANSI yellow
- Definition Classes
- AnsiColor
final val YELLOW_B: String("\u001B[43m")
Background color for ANSI yellow
- Definition Classes
- AnsiColor
final def asInstanceOf[T0]: T0
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.
- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastExceptionif the receiver object is not an instance of the erasure of typeT0.
def clone(): AnyRef
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
- returns
a copy of the receiver object.
final def eq(arg0: AnyRef): Boolean
Tests whether the argument (that) is a reference to the receiver object (this).
The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:
-
It is consistent: for any non-null instances
x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
null.eq(null) returns true. When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
- returns
trueif the argument is a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
def equals(arg0: AnyRef): Boolean
The equality method for reference types. Default implementation delegates to eq.
See also equals in scala.Any.
- returns
trueif the receiver object is equivalent to the argument;falseotherwise.
- Definition Classes
- AnyRef → Any
def err: PrintStream
def finalize(): Unit
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.
def flush(): Unit
Flushes the output stream. This function is required when partial output (i.e. output not terminated by a newline character) has to be made visible on the terminal.
final def getClass(): Class[_ <: AnyRef]
Returns the runtime class representation of the object.
- returns
a class object corresponding to the runtime type of the receiver.
def hashCode(): Int
The hashCode method for reference types. See hashCode in scala.Any.
- returns
the hash code value for this object.
def in: BufferedReader
final def isInstanceOf[T0]: Boolean
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.
- returns
trueif the receiver object is an instance of erasure of typeT0;falseotherwise.
- Definition Classes
- Any
final def ne(arg0: AnyRef): Boolean
Equivalent to !(this eq that).
- returns
trueif the argument is not a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
final def notify(): Unit
Wakes up a single thread that is waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
final def notifyAll(): Unit
Wakes up all threads that are waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
def out: PrintStream
def print(obj: Any): Unit
Prints an object to out using its toString method.
- obj
the object to print; may be null.
def printf(text: String, args: Any*): Unit
Prints its arguments as a formatted string to the default output, based on a string pattern (in a fashion similar to printf in C).
The interpretation of the formatting patterns is described in java.util.Formatter.
- text
the pattern for formatting the arguments.
- args
the arguments used to instantiating the pattern.
- Exceptions thrown
java.lang.IllegalArgumentExceptionif there was a problem with the format string or arguments
def println(x: Any): Unit
Prints out an object to the default output, followed by a newline character.
- x
the object to print.
def println(): Unit
def setErrDirect(err: PrintStream): Unit
- Attributes
- protected
def setInDirect(in: BufferedReader): Unit
- Attributes
- protected
def setOutDirect(out: PrintStream): Unit
- Attributes
- protected
final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
def toString(): String
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
- returns
a String representation of the object.
- Definition Classes
- AnyRef → Any
final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
def withErr[T](err: OutputStream)(thunk: => T): T
Sets the default error stream for the duration of execution of one thunk.
- err
the new error stream.
- thunk
the code to execute with the new error stream active
- returns
the results of
thunk
- See also
withErr[T](err:PrintStream)(thunk: =>T)
def withErr[T](err: PrintStream)(thunk: => T): T
Set the default error stream for the duration of execution of one thunk.
- err
the new error stream.
- thunk
the code to execute with the new error stream active
- returns
the results of
thunk
- See also
withErr[T](err:OutputStream)(thunk: =>T)
withErr(Console.out) { err.println("This goes to default _out_") }
def withIn[T](in: InputStream)(thunk: => T): T
Sets the default input stream for the duration of execution of one thunk.
- in
the new input stream.
- thunk
the code to execute with the new input stream active
- returns
the results of
thunk
- See also
withIn[T](reader:Reader)(thunk: =>T)
def withIn[T](reader: Reader)(thunk: => T): T
Sets the default input stream for the duration of execution of one thunk.
- thunk
the code to execute with the new input stream active
- returns
the results of
thunk
- See also
withIn[T](in:InputStream)(thunk: =>T)
val someFile:Reader = openFile("file.txt")
withIn(someFile) {
// Reads a line from file.txt instead of default input
println(readLine)
}
def withOut[T](out: OutputStream)(thunk: => T): T
Sets the default output stream for the duration of execution of one thunk.
- out
the new output stream.
- thunk
the code to execute with the new output stream active
- returns
the results of
thunk
- See also
withOut[T](out:PrintStream)(thunk: => T)
def withOut[T](out: PrintStream)(thunk: => T): T
Sets the default output stream for the duration of execution of one thunk.
- out
the new output stream.
- thunk
the code to execute with the new output stream active
- returns
the results of
thunk
- See also
withOut[T](out:OutputStream)(thunk: => T)
withOut(Console.err) { println("This goes to default _error_") }
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala/Console$.html
Implements functionality for printing Scala values on the terminal. For reading values use StdIn. Also defines constants for marking up text on ANSI terminals.
Console Output
Use the print methods to output text.
ANSI escape codes
Use the ANSI escape codes for colorizing console output either to STDOUT or STDERR.
import Console.{GREEN, RED, RESET, YELLOW_B, UNDERLINED} object PrimeTest { def isPrime(): Unit = { val candidate = io.StdIn.readInt().ensuring(_ > 1) val prime = (2 to candidate - 1).forall(candidate % _ != 0) if (prime) Console.println(s"${RESET}${GREEN}yes${RESET}") else Console.err.println(s"${RESET}${YELLOW_B}${RED}${UNDERLINED}NO!${RESET}") } def main(args: Array[String]): Unit = isPrime() }IO redefinition
Use IO redefinition to temporarily swap in a different set of input and/or output streams. In this example the stream based method above is wrapped into a function.
import java.io.{ByteArrayOutputStream, StringReader} object FunctionalPrimeTest { def isPrime(candidate: Int): Boolean = { val input = new StringReader(s"$candidate\n") val outCapture = new ByteArrayOutputStream val errCapture = new ByteArrayOutputStream Console.withIn(input) { Console.withOut(outCapture) { Console.withErr(errCapture) { PrimeTest.isPrime() } } } if (outCapture.toByteArray.nonEmpty) // "yes" true else if (errCapture.toByteArray.nonEmpty) // "NO!" false else throw new IllegalArgumentException(candidate.toString) } def main(args: Array[String]): Unit = { val primes = (2 to 50) filter (isPrime) println(s"First primes: $primes") } }1.0