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Scala example source code file (TableDef.scala)
The TableDef.scala Scala example source codepackage scala package reflect.internal.util import TableDef._ import scala.language.postfixOps /** A class for representing tabular data in a way that preserves * its inner beauty. * One creates an instance of TableDef by defining the columns of * the table, then uses that to create an instance of Table by * passing in a sequence of rows. */ class TableDef[T](_cols: Column[T]*) { // These operators are about all there is to it. /** Appends a column to the table. */ def ~(next: Column[T]) = retThis(cols :+= next) // Below this point should all be considered private/internal. private var cols: List[Column[T]] = _cols.toList def defaultSep(index: Int) = if (index > (cols.size - 2)) "" else " " def sepAfter(i: Int): String = defaultSep(i) def sepWidths = cols.indices map (i => sepAfter(i).length) def colNames = cols map (_.name) def colFunctions = cols map (_.f) def colApply(el: T) = colFunctions map (f => f(el)) def retThis(body: => Unit): this.type = { body ; this } class Table(val rows: Seq[T]) extends Seq[T] { def iterator = rows.iterator def apply(index: Int) = rows(index) def length = rows.length def maxColWidth(col: Column[T]) = col.name +: (rows map col.f) map (_.toString.length) max def specs = cols map (_ formatSpec rows) val colWidths = cols map maxColWidth val rowFormat = mkFormatString(sepAfter) val headFormat = mkFormatString(i => " " * sepWidths(i)) val argLists = rows map colApply val headers = List( headFormat.format(colNames: _*), (colWidths, sepWidths).zipped map ((w1, w2) => "-" * w1 + " " * w2) mkString ) def mkFormatString(sepf: Int => String): String = specs.zipWithIndex map { case (c, i) => c + sepf(i) } mkString def toFormattedSeq = argLists map (xs => rowFormat.format(xs: _*)) def allToSeq = headers ++ toFormattedSeq override def toString = allToSeq mkString "\n" } def table(rows: Seq[T]) = new Table(rows) override def toString = cols.mkString("TableDef(", ", ", ")") } object TableDef { case class Column[-T](name: String, f: T => Any, left: Boolean) { def maxWidth(elems: Seq[T]): Int = name +: (elems map f) map (_.toString.length) max def formatSpec(elems: Seq[T]): String = { val justify = if (left) "-" else "" "%" + justify + maxWidth(elems) + "s" } override def toString = { val justify = if (left) "<<" else ">>" justify + "(" + name + ")" } } def apply[T](cols: Column[T]*) = new TableDef[T](cols: _*) } Other Scala source code examplesHere is a short list of links related to this Scala TableDef.scala source code file: |
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