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Standard library for the Scala Programming Language
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala
import java.io.{BufferedReader, InputStream, InputStreamReader,
IOException, OutputStream, PrintStream, Reader}
import java.text.MessageFormat
import scala.util.DynamicVariable
/** Implements functionality for
* printing Scala values on the terminal as well as reading specific values.
* Also defines constants for marking up text on ANSI terminals.
*
* @author Matthias Zenger
* @version 1.0, 03/09/2003
*/
object Console {
/** Foreground color for ANSI black */
final val BLACK = "\033[30m"
/** Foreground color for ANSI red */
final val RED = "\033[31m"
/** Foreground color for ANSI green */
final val GREEN = "\033[32m"
/** Foreground color for ANSI yellow */
final val YELLOW = "\033[33m"
/** Foreground color for ANSI blue */
final val BLUE = "\033[34m"
/** Foreground color for ANSI magenta */
final val MAGENTA = "\033[35m"
/** Foreground color for ANSI cyan */
final val CYAN = "\033[36m"
/** Foreground color for ANSI white */
final val WHITE = "\033[37m"
/** Background color for ANSI black */
final val BLACK_B = "\033[40m"
/** Background color for ANSI red */
final val RED_B = "\033[41m"
/** Background color for ANSI green */
final val GREEN_B = "\033[42m"
/** Background color for ANSI yellow */
final val YELLOW_B = "\033[43m"
/** Background color for ANSI blue */
final val BLUE_B = "\033[44m"
/** Background color for ANSI magenta */
final val MAGENTA_B = "\033[45m"
/** Background color for ANSI cyan */
final val CYAN_B = "\033[46m"
/** Background color for ANSI white */
final val WHITE_B = "\033[47m"
/** Reset ANSI styles */
final val RESET = "\033[0m"
/** ANSI bold */
final val BOLD = "\033[1m"
/** ANSI underlines */
final val UNDERLINED = "\033[4m"
/** ANSI blink */
final val BLINK = "\033[5m"
/** ANSI reversed */
final val REVERSED = "\033[7m"
/** ANSI invisible */
final val INVISIBLE = "\033[8m"
private val outVar = new DynamicVariable[PrintStream](java.lang.System.out)
private val errVar = new DynamicVariable[PrintStream](java.lang.System.err)
private val inVar = new DynamicVariable[BufferedReader](
new BufferedReader(new InputStreamReader(java.lang.System.in)))
/** The default output, can be overridden by `setOut` */
def out = outVar.value
/** The default error, can be overridden by `setErr` */
def err = errVar.value
/** The default input, can be overridden by `setIn` */
def in = inVar.value
/** Sets the default output stream.
*
* @param out the new output stream.
*/
def setOut(out: PrintStream) { outVar.value = out }
/** Sets the default output stream for the duration
* of execution of one thunk.
*
* @example {{{
* withOut(Console.err) { println("This goes to default _error_") }
* }}}
*
* @param out the new output stream.
* @param thunk the code to execute with
* the new output stream active
* @return the results of `thunk`
* @see `withOut[T](out:OutputStream)(thunk: => T)`
*/
def withOut[T](out: PrintStream)(thunk: =>T): T =
outVar.withValue(out)(thunk)
/** Sets the default output stream.
*
* @param out the new output stream.
*/
def setOut(out: OutputStream): Unit =
setOut(new PrintStream(out))
/** Sets the default output stream for the duration
* of execution of one thunk.
*
* @param out the new output stream.
* @param thunk the code to execute with
* the new output stream active
* @return the results of `thunk`
* @see `withOut[T](out:PrintStream)(thunk: => T)`
*/
def withOut[T](out: OutputStream)(thunk: =>T): T =
withOut(new PrintStream(out))(thunk)
/** Sets the default error stream.
*
* @param err the new error stream.
*/
def setErr(err: PrintStream) { errVar.value = err }
/** Set the default error stream for the duration
* of execution of one thunk.
* @example {{{
* withErr(Console.out) { println("This goes to default _out_") }
* }}}
*
* @param err the new error stream.
* @param thunk the code to execute with
* the new error stream active
* @return the results of `thunk`
* @see `withErr[T](err:OutputStream)(thunk: =>T)`
*/
def withErr[T](err: PrintStream)(thunk: =>T): T =
errVar.withValue(err)(thunk)
/** Sets the default error stream.
*
* @param err the new error stream.
*/
def setErr(err: OutputStream): Unit =
setErr(new PrintStream(err))
/** Sets the default error stream for the duration
* of execution of one thunk.
*
* @param err the new error stream.
* @param thunk the code to execute with
* the new error stream active
* @return the results of `thunk`
* @see `withErr[T](err:PrintStream)(thunk: =>T)`
*/
def withErr[T](err: OutputStream)(thunk: =>T): T =
withErr(new PrintStream(err))(thunk)
/** Sets the default input stream.
*
* @param reader specifies the new input stream.
*/
def setIn(reader: Reader) {
inVar.value = new BufferedReader(reader)
}
/** Sets the default input stream for the duration
* of execution of one thunk.
*
* @example {{{
* val someFile:Reader = openFile("file.txt")
* withIn(someFile) {
* // Reads a line from file.txt instead of default input
* println(readLine)
* }
* }}}
*
* @param thunk the code to execute with
* the new input stream active
*
* @return the results of `thunk`
* @see `withIn[T](in:InputStream)(thunk: =>T)`
*/
def withIn[T](reader: Reader)(thunk: =>T): T =
inVar.withValue(new BufferedReader(reader))(thunk)
/** Sets the default input stream.
*
* @param in the new input stream.
*/
def setIn(in: InputStream) {
setIn(new InputStreamReader(in))
}
/** Sets the default input stream for the duration
* of execution of one thunk.
*
* @param in the new input stream.
* @param thunk the code to execute with
* the new input stream active
* @return the results of `thunk`
* @see `withIn[T](reader:Reader)(thunk: =>T)`
*/
def withIn[T](in: InputStream)(thunk: =>T): T =
withIn(new InputStreamReader(in))(thunk)
/** Prints an object to `out` using its `toString` method.
*
* @param obj the object to print; may be null.
*/
def print(obj: Any) {
out.print(if (null == obj) "null" else obj.toString())
}
/** 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.
*/
def flush() { out.flush() }
/** Prints a newline character on the default output.
*/
def println() { out.println() }
/** Prints out an object to the default output, followed by a newline character.
*
* @param x the object to print.
*/
def println(x: Any) { out.println(x) }
/** 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`.
*
* @param text the pattern for formatting the arguments.
* @param args the arguments used to instantiating the pattern.
* @throws java.lang.IllegalArgumentException if there was a problem with the format string or arguments
*/
def printf(text: String, args: Any*) { out.print(text format (args : _*)) }
/** Read a full line from the default input. Returns `null` if the end of the
* input stream has been reached.
*
* @return the string read from the terminal or null if the end of stream was reached.
*/
def readLine(): String = in.readLine()
/** Print formatted text to the default output and read a full line from the default input.
* Returns `null` if the end of the input stream has been reached.
*
* @param text the format of the text to print out, as in `printf`.
* @param args the parameters used to instantiate the format, as in `printf`.
* @return the string read from the default input
*/
def readLine(text: String, args: Any*): String = {
printf(text, args: _*)
readLine()
}
/** Reads a boolean value from an entire line of the default input.
* Has a fairly liberal interpretation of the input.
*
* @return the boolean value read, or false if it couldn't be converted to a boolean
* @throws java.io.EOFException if the end of the input stream has been reached.
*/
def readBoolean(): Boolean = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s.toLowerCase() match {
case "true" => true
case "t" => true
case "yes" => true
case "y" => true
case _ => false
}
}
/** Reads a byte value from an entire line of the default input.
*
* @return the Byte that was read
* @throws java.io.EOFException if the end of the
* input stream has been reached.
* @throws java.lang.NumberFormatException if the value couldn't be converted to a Byte
*/
def readByte(): Byte = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s.toByte
}
/** Reads a short value from an entire line of the default input.
*
* @return the short that was read
* @throws java.io.EOFException if the end of the
* input stream has been reached.
* @throws java.lang.NumberFormatException if the value couldn't be converted to a Short
*/
def readShort(): Short = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s.toShort
}
/** Reads a char value from an entire line of the default input.
*
* @return the Char that was read
* @throws java.io.EOFException if the end of the
* input stream has been reached.
* @throws java.lang.StringIndexOutOfBoundsException if the line read from default input was empty
*/
def readChar(): Char = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s charAt 0
}
/** Reads an int value from an entire line of the default input.
*
* @return the Int that was read
* @throws java.io.EOFException if the end of the
* input stream has been reached.
* @throws java.lang.NumberFormatException if the value couldn't be converted to an Int
*/
def readInt(): Int = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s.toInt
}
/** Reads an long value from an entire line of the default input.
*
* @return the Long that was read
* @throws java.io.EOFException if the end of the
* input stream has been reached.
* @throws java.lang.NumberFormatException if the value couldn't be converted to a Long
*/
def readLong(): Long = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s.toLong
}
/** Reads a float value from an entire line of the default input.
* @return the Float that was read.
* @throws java.io.EOFException if the end of the
* input stream has been reached.
* @throws java.lang.NumberFormatException if the value couldn't be converted to a Float
*
*/
def readFloat(): Float = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s.toFloat
}
/** Reads a double value from an entire line of the default input.
*
* @return the Double that was read.
* @throws java.io.EOFException if the end of the
* input stream has been reached.
* @throws java.lang.NumberFormatException if the value couldn't be converted to a Float
*/
def readDouble(): Double = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
s.toDouble
}
/** Reads in some structured input (from the default input), specified by
* a format specifier. See class `java.text.MessageFormat` for details of
* the format specification.
*
* @param format the format of the input.
* @return a list of all extracted values.
* @throws java.io.EOFException if the end of the input stream has been
* reached.
*/
def readf(format: String): List[Any] = {
val s = readLine()
if (s == null)
throw new java.io.EOFException("Console has reached end of input")
else
textComponents(new MessageFormat(format).parse(s))
}
/** Reads in some structured input (from the default input), specified by
* a format specifier, returning only the first value extracted, according
* to the format specification.
*
* @param format format string, as accepted by `readf`.
* @return The first value that was extracted from the input
*/
def readf1(format: String): Any = readf(format).head
/** Reads in some structured input (from the default input), specified
* by a format specifier, returning only the first two values extracted,
* according to the format specification.
*
* @param format format string, as accepted by `readf`.
* @return A [[scala.Tuple2]] containing the first two values extracted
*/
def readf2(format: String): (Any, Any) = {
val res = readf(format)
(res.head, res.tail.head)
}
/** Reads in some structured input (from the default input), specified
* by a format specifier, returning only the first three values extracted,
* according to the format specification.
*
* @param format format string, as accepted by `readf`.
* @return A [[scala.Tuple3]] containing the first three values extracted
*/
def readf3(format: String): (Any, Any, Any) = {
val res = readf(format)
(res.head, res.tail.head, res.tail.tail.head)
}
private def textComponents(a: Array[AnyRef]): List[Any] = {
var i: Int = a.length - 1
var res: List[Any] = Nil
while (i >= 0) {
res = (a(i) match {
case x: java.lang.Boolean => x.booleanValue()
case x: java.lang.Byte => x.byteValue()
case x: java.lang.Short => x.shortValue()
case x: java.lang.Character => x.charValue()
case x: java.lang.Integer => x.intValue()
case x: java.lang.Long => x.longValue()
case x: java.lang.Float => x.floatValue()
case x: java.lang.Double => x.doubleValue()
case x => x
}) :: res;
i -= 1
}
res
}
}