/* NSC -- new Scala compiler
* Copyright 2006-2013 LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package util
import scala.reflect.internal.Chars._
/** Utility methods for doc comment strings
*/
object DocStrings {
/** Returns index of string `str` following `start` skipping longest
* sequence of whitespace characters characters (but no newlines)
*/
def skipWhitespace(str: String, start: Int): Int =
if (start < str.length && isWhitespace(str charAt start)) skipWhitespace(str, start + 1)
else start
/** Returns index of string `str` following `start` skipping
* sequence of identifier characters.
*/
def skipIdent(str: String, start: Int): Int =
if (start < str.length && isIdentifierPart(str charAt start)) skipIdent(str, start + 1)
else start
/** Returns index of string `str` following `start` skipping
* sequence of identifier characters.
*/
def skipTag(str: String, start: Int): Int =
if (start < str.length && (str charAt start) == '@') skipIdent(str, start + 1)
else start
/** Returns index of string `str` after `start` skipping longest
* sequence of space and tab characters, possibly also containing
* a single `*` character or the `/``**` sequence.
* @pre start == str.length || str(start) == `\n`
*/
def skipLineLead(str: String, start: Int): Int =
if (start == str.length) start
else {
val idx = skipWhitespace(str, start + 1)
if (idx < str.length && (str charAt idx) == '*') skipWhitespace(str, idx + 1)
else if (idx + 2 < str.length && (str charAt idx) == '/' && (str charAt (idx + 1)) == '*' && (str charAt (idx + 2)) == '*')
skipWhitespace(str, idx + 3)
else idx
}
/** Skips to next occurrence of `\n` or to the position after the `/``**` sequence following index `start`.
*/
def skipToEol(str: String, start: Int): Int =
if (start + 2 < str.length && (str charAt start) == '/' && (str charAt (start + 1)) == '*' && (str charAt (start + 2)) == '*') start + 3
else if (start < str.length && (str charAt start) != '\n') skipToEol(str, start + 1)
else start
/** Returns first index following `start` and starting a line (i.e. after skipLineLead) or starting the comment
* which satisfies predicate `p`.
*/
def findNext(str: String, start: Int)(p: Int => Boolean): Int = {
val idx = skipLineLead(str, skipToEol(str, start))
if (idx < str.length && !p(idx)) findNext(str, idx)(p)
else idx
}
/** Return first index following `start` and starting a line (i.e. after skipLineLead)
* which satisfies predicate `p`.
*/
def findAll(str: String, start: Int)(p: Int => Boolean): List[Int] = {
val idx = findNext(str, start)(p)
if (idx == str.length) List()
else idx :: findAll(str, idx)(p)
}
/** Produces a string index, which is a list of `sections`, i.e
* pairs of start/end positions of all tagged sections in the string.
* Every section starts with an at sign and extends to the next at sign,
* or to the end of the comment string, but excluding the final two
* characters which terminate the comment.
*
* Also take usecases into account - they need to expand until the next
* usecase or the end of the string, as they might include other sections
* of their own
*/
def tagIndex(str: String, p: Int => Boolean = (idx => true)): List[(Int, Int)] = {
var indices = findAll(str, 0) (idx => str(idx) == '@' && p(idx))
indices = mergeUsecaseSections(str, indices)
indices = mergeInheritdocSections(str, indices)
indices match {
case List() => List()
case idxs => idxs zip (idxs.tail ::: List(str.length - 2))
}
}
/**
* Merge sections following an usecase into the usecase comment, so they
* can override the parent symbol's sections
*/
def mergeUsecaseSections(str: String, idxs: List[Int]): List[Int] = {
idxs.indexWhere(str.startsWith("@usecase", _)) match {
case firstUCIndex if firstUCIndex != -1 =>
val commentSections = idxs.take(firstUCIndex)
val usecaseSections = idxs.drop(firstUCIndex).filter(str.startsWith("@usecase", _))
commentSections ::: usecaseSections
case _ =>
idxs
}
}
/**
* Merge the inheritdoc sections, as they never make sense on their own
*/
def mergeInheritdocSections(str: String, idxs: List[Int]): List[Int] =
idxs.filterNot(str.startsWith("@inheritdoc", _))
/** Does interval `iv` start with given `tag`?
*/
def startsWithTag(str: String, section: (Int, Int), tag: String): Boolean =
startsWithTag(str, section._1, tag)
def startsWithTag(str: String, start: Int, tag: String): Boolean =
str.startsWith(tag, start) && !isIdentifierPart(str charAt (start + tag.length))
/** The first start tag of a list of tag intervals,
* or the end of the whole comment string - 2 if list is empty
*/
def startTag(str: String, sections: List[(Int, Int)]) = sections match {
case Nil => str.length - 2
case (start, _) :: _ => start
}
/** A map from parameter names to start/end indices describing all parameter
* sections in `str` tagged with `tag`, where `sections` is the index of `str`.
*/
def paramDocs(str: String, tag: String, sections: List[(Int, Int)]): Map[String, (Int, Int)] =
Map() ++ {
for (section <- sections if startsWithTag(str, section, tag)) yield {
val start = skipWhitespace(str, section._1 + tag.length)
str.substring(start, skipIdent(str, start)) -> section
}
}
/** Optionally start and end index of return section in `str`, or `None`
* if `str` does not have a @group. */
def groupDoc(str: String, sections: List[(Int, Int)]): Option[(Int, Int)] =
sections find (startsWithTag(str, _, "@group"))
/** Optionally start and end index of return section in `str`, or `None`
* if `str` does not have a @return.
*/
def returnDoc(str: String, sections: List[(Int, Int)]): Option[(Int, Int)] =
sections find (startsWithTag(str, _, "@return"))
/** Extracts variable name from a string, stripping any pair of surrounding braces */
def variableName(str: String): String =
if (str.length >= 2 && (str charAt 0) == '{' && (str charAt (str.length - 1)) == '}')
str.substring(1, str.length - 1)
else
str
/** Returns index following variable, or start index if no variable was recognized
*/
def skipVariable(str: String, start: Int): Int = {
var idx = start
if (idx < str.length && (str charAt idx) == '{') {
do idx += 1
while (idx < str.length && (str charAt idx) != '}')
if (idx < str.length) idx + 1 else start
} else {
while (idx < str.length && isVarPart(str charAt idx))
idx += 1
idx
}
}
/** A map from the section tag to section parameters */
def sectionTagMap(str: String, sections: List[(Int, Int)]): Map[String, (Int, Int)] =
Map() ++ {
for (section <- sections) yield
extractSectionTag(str, section) -> section
}
/** Extract the section tag, treating the section tag as an identifier */
def extractSectionTag(str: String, section: (Int, Int)): String =
str.substring(section._1, skipTag(str, section._1))
/** Extract the section parameter */
def extractSectionParam(str: String, section: (Int, Int)): String = {
val (beg, _) = section
assert(str.startsWith("@param", beg) ||
str.startsWith("@tparam", beg) ||
str.startsWith("@throws", beg))
val start = skipWhitespace(str, skipTag(str, beg))
val finish = skipIdent(str, start)
str.substring(start, finish)
}
/** Extract the section text, except for the tag and comment newlines */
def extractSectionText(str: String, section: (Int, Int)): (Int, Int) = {
val (beg, end) = section
if (str.startsWith("@param", beg) ||
str.startsWith("@tparam", beg) ||
str.startsWith("@throws", beg))
(skipWhitespace(str, skipIdent(str, skipWhitespace(str, skipTag(str, beg)))), end)
else
(skipWhitespace(str, skipTag(str, beg)), end)
}
/** Cleanup section text */
def cleanupSectionText(str: String) = {
var result = str.trim.replaceAll("\n\\s+\\*\\s+", " \n")
while (result.endsWith("\n"))
result = result.substring(0, str.length - 1)
result
}
}
