package dotty.tools
package dotc
package util
import scala.collection.mutable.ArrayBuffer
import dotty.tools.io._
import annotation.tailrec
import java.util.regex.Pattern
import java.io.IOException
import Chars._
import ScriptSourceFile._
import Positions._
object ScriptSourceFile {
private val headerPattern = Pattern.compile("""^(::)?!#.*(\r|\n|\r\n)""", Pattern.MULTILINE)
private val headerStarts = List("#!", "::#!")
def apply(file: AbstractFile, content: Array[Char]) = {
/** 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 "::!#".
*/
val headerLength =
if (headerStarts exists (content startsWith _)) {
val matcher = headerPattern matcher content.mkString
if (matcher.find) matcher.end
else throw new IOException("script file does not close its header with !# or ::!#")
} else 0
new SourceFile(file, content drop headerLength) {
override val underlying = new SourceFile(file, content)
}
}
}
case class SourceFile(file: AbstractFile, content: Array[Char]) {
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)
override def equals(that : Any) = that match {
case that : SourceFile => file.path == that.file.path && start == that.start
case _ => false
}
override def hashCode = file.path.## + start.##
val length = content.length
/** true for all source files except `NoSource` */
def exists: Boolean = true
/** The underlying source file */
def underlying: SourceFile = this
/** The start of this file in the underlying source file */
def start = 0
def atPos(pos: Position): SourcePosition =
SourcePosition(underlying, pos)
def isSelfContained = underlying eq this
/** Map a position to a position in the underlying source file.
* For regular source files, simply return the argument.
*/
def positionInUltimateSource(position: SourcePosition): SourcePosition =
SourcePosition(underlying, position.pos shift start)
def isLineBreak(idx: Int) =
if (idx >= length) false else {
val ch = content(idx)
// don't identify the CR in CR LF as a line break, since LF will do.
if (ch == CR) (idx + 1 == length) || (content(idx + 1) != LF)
else isLineBreakChar(ch)
}
def calculateLineIndices(cs: Array[Char]) = {
val buf = new ArrayBuffer[Int]
buf += 0
for (i <- 0 until cs.length) if (isLineBreak(i)) buf += i + 1
buf += cs.length // sentinel, so that findLine below works smoother
buf.toArray
}
private lazy val lineIndices: Array[Int] = calculateLineIndices(content)
/** Map line to offset of first character in line */
def lineToOffset(index : Int): Int = lineIndices(index)
/** A cache to speed up offsetToLine searches to similar lines */
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 (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
}
}
object NoSource extends SourceFile("<no source>", Nil) {
override def exists = false
}