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Scala example source code file (SourceFile.scala)
The SourceFile.scala Scala example source code/* NSC -- new Scala compiler * Copyright 2005-2013 LAMP/EPFL * @author Martin Odersky */ package scala package reflect.internal.util import scala.reflect.io.{ AbstractFile, VirtualFile } import scala.collection.mutable.ArrayBuffer import scala.annotation.tailrec import java.util.regex.Pattern import java.io.IOException import scala.reflect.internal.Chars._ /** abstract base class of a source file used in the compiler */ abstract class SourceFile { def content: Array[Char] // normalized, must end in SU def file : AbstractFile def isLineBreak(idx: Int): Boolean def isEndOfLine(idx: Int): Boolean def isSelfContained: Boolean def length : Int def position(offset: Int): Position = { assert(offset < length, file + ": " + offset + " >= " + length) Position.offset(this, offset) } def offsetToLine(offset: Int): Int def lineToOffset(index : Int): Int /** Map a position to a position in the underlying source file. * For regular source files, simply return the argument. */ def positionInUltimateSource(position: Position) = position override def toString() = file.name def path = file.path def lineToString(index: Int): String = { val start = lineToOffset(index) var end = start while (!isEndOfLine(end) && end <= length) end += 1 new String(content, start, end - start) } @tailrec final def skipWhitespace(offset: Int): Int = if (content(offset).isWhitespace) skipWhitespace(offset + 1) else offset def identifier(pos: Position): Option[String] = None } /** An object representing a missing source file. */ object NoSourceFile extends SourceFile { def content = Array() def file = NoFile def isLineBreak(idx: Int) = false def isEndOfLine(idx: Int) = false def isSelfContained = true def length = -1 def offsetToLine(offset: Int) = -1 def lineToOffset(index : Int) = -1 override def toString = "<no source file>" } object NoFile extends VirtualFile("<no file>", "<no file>") object ScriptSourceFile { /** Length of the script header from the given content, if there is one. * The header begins with "#!" or "::#!" and ends with a line starting * with "!#" or "::!#". */ def headerLength(cs: Array[Char]): Int = { val headerPattern = Pattern.compile("""((?m)^(::)?!#.*|^.*/env .*)(\r|\n|\r\n)""") val headerStarts = List("#!", "::#!") if (headerStarts exists (cs startsWith _)) { val matcher = headerPattern matcher cs.mkString if (matcher.find) matcher.end else throw new IOException("script file does not close its header with !# or ::!#") } else 0 } def apply(file: AbstractFile, content: Array[Char]) = { val underlying = new BatchSourceFile(file, content) val headerLen = headerLength(content) val stripped = new ScriptSourceFile(underlying, content drop headerLen, headerLen) stripped } def apply(underlying: BatchSourceFile) = { val headerLen = headerLength(underlying.content) new ScriptSourceFile(underlying, underlying.content drop headerLen, headerLen) } } class ScriptSourceFile(underlying: BatchSourceFile, content: Array[Char], override val start: Int) extends BatchSourceFile(underlying.file, content) { override def isSelfContained = false override def positionInUltimateSource(pos: Position) = if (!pos.isDefined) super.positionInUltimateSource(pos) else pos withSource underlying withShift start } /** a file whose contents do not change over time */ class BatchSourceFile(val file : AbstractFile, content0: Array[Char]) extends SourceFile { def this(_file: AbstractFile) = this(_file, _file.toCharArray) def this(sourceName: String, cs: Seq[Char]) = this(new VirtualFile(sourceName), cs.toArray) def this(file: AbstractFile, cs: Seq[Char]) = this(file, cs.toArray) // If non-whitespace tokens run all the way up to EOF, // positions go wrong because the correct end of the last // token cannot be used as an index into the char array. // The least painful way to address this was to add a // newline to the array. val content = ( if (content0.length == 0 || !content0.last.isWhitespace) content0 :+ '\n' else content0 ) val length = content.length def start = 0 def isSelfContained = true override def identifier(pos: Position) = if (pos.isDefined && pos.source == this && pos.point != -1) { def isOK(c: Char) = isIdentifierPart(c) || isOperatorPart(c) Some(new String(content drop pos.point takeWhile isOK)) } else { super.identifier(pos) } private def charAtIsEOL(idx: Int)(p: Char => Boolean) = { // don't identify the CR in CR LF as a line break, since LF will do. def notCRLF0 = content(idx) != CR || !content.isDefinedAt(idx + 1) || content(idx + 1) != LF idx < length && notCRLF0 && p(content(idx)) } def isLineBreak(idx: Int) = charAtIsEOL(idx)(isLineBreakChar) /** True if the index is included by an EOL sequence. */ def isEndOfLine(idx: Int) = (content isDefinedAt idx) && PartialFunction.cond(content(idx)) { case CR | LF => true } /** True if the index is end of an EOL sequence. */ def isAtEndOfLine(idx: Int) = charAtIsEOL(idx) { case CR | LF => true case _ => false } def calculateLineIndices(cs: Array[Char]) = { val buf = new ArrayBuffer[Int] buf += 0 for (i <- 0 until cs.length) if (isAtEndOfLine(i)) buf += i + 1 buf += cs.length // sentinel, so that findLine below works smoother buf.toArray } private lazy val lineIndices: Array[Int] = calculateLineIndices(content) def lineToOffset(index : Int): Int = lineIndices(index) private var lastLine = 0 /** Convert offset to line in this source file. * Lines are numbered from 0. */ def offsetToLine(offset: Int): Int = { val lines = lineIndices def findLine(lo: Int, hi: Int, mid: Int): Int = ( if (mid < lo || hi < mid) mid // minimal sanity check - as written this easily went into infinite loopyland else if (offset < lines(mid)) findLine(lo, mid - 1, (lo + mid - 1) / 2) else if (offset >= lines(mid + 1)) findLine(mid + 1, hi, (mid + 1 + hi) / 2) else mid ) lastLine = findLine(0, lines.length, lastLine) lastLine } override def equals(that : Any) = that match { case that : BatchSourceFile => file.path == that.file.path && start == that.start case _ => false } override def hashCode = file.path.## + start.## } Other Scala source code examplesHere is a short list of links related to this Scala SourceFile.scala source code file: |
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