package dotty.tools
package dotc
package repl
import parsing.Tokens._
import ammonite.terminal.FilterTools._
import ammonite.terminal.LazyList._
import ammonite.terminal.SpecialKeys._
import ammonite.terminal.Filter
import ammonite.terminal._
import scala.annotation.switch
import scala.collection.mutable.StringBuilder
/** This object provides functions for syntax highlighting in the REPL */
object SyntaxHighlighting {
val NoColor = Console.RESET
val CommentColor = Console.GREEN
val KeywordColor = Console.CYAN
val LiteralColor = Console.MAGENTA
val TypeColor = Console.GREEN
val AnnotationColor = Console.RED
private def none(str: String) = str
private def keyword(str: String) = KeywordColor + str + NoColor
private def typeDef(str: String) = TypeColor + str + NoColor
private def literal(str: String) = LiteralColor + str + NoColor
private def annotation(str: String) = AnnotationColor + str + NoColor
private val keywords: Seq[String] = for {
index <- IF to FORSOME // All alpha keywords
} yield tokenString(index)
private val interpolationPrefixes =
'A' :: 'B' :: 'C' :: 'D' :: 'E' :: 'F' :: 'G' :: 'H' :: 'I' :: 'J' :: 'K' ::
'L' :: 'M' :: 'N' :: 'O' :: 'P' :: 'Q' :: 'R' :: 'S' :: 'T' :: 'U' :: 'V' ::
'W' :: 'X' :: 'Y' :: 'Z' :: '$' :: '_' :: 'a' :: 'b' :: 'c' :: 'd' :: 'e' ::
'f' :: 'g' :: 'h' :: 'i' :: 'j' :: 'k' :: 'l' :: 'm' :: 'n' :: 'o' :: 'p' ::
'q' :: 'r' :: 's' :: 't' :: 'u' :: 'v' :: 'w' :: 'x' :: 'y' :: 'z' :: Nil
private val typeEnders =
'{' :: '}' :: ')' :: '(' :: '=' :: ' ' :: ',' :: '.' :: Nil
def apply(buffer: Iterable[Char]): Vector[Char] = {
var prev: Char = 0
var iter = buffer.toIterator
val newBuf = new StringBuilder
@inline def keywordStart =
prev == 0 || prev == ' ' || prev == '{' || prev == '('
@inline def numberStart(c: Char) =
c.isDigit && (!prev.isLetter || prev == '.' || prev == ' ' || prev == '(' || prev == '\u0000')
while (iter.hasNext) {
val n = iter.next
if (interpolationPrefixes.contains(n)) {
// Interpolation prefixes are a superset of the keyword start chars
val next = iter.take(3).mkString
if (next.startsWith("\"")) {
newBuf += n
prev = n
appendLiteral('"', next.toIterator.drop(1), next == "\"\"\"")
} else {
val (dup, _ ) = iter.duplicate
iter = next.toIterator ++ dup
if (n.isUpper && keywordStart) {
appendWhile(n, !typeEnders.contains(_), typeDef)
} else if (keywordStart) {
append(n, keywords.contains(_), keyword)
} else {
newBuf += n
prev = n
}
}
} else {
(n: @switch) match {
case '/' =>
if (iter.hasNext) {
iter.next match {
case '/' => eolComment()
case '*' => blockComment()
case x => {
newBuf += '/'
val (dup, _) = iter.duplicate
iter = List(x).toIterator ++ dup
}
}
} else newBuf += '/'
case '=' =>
append('=', _ == "=>", keyword)
case '<' =>
append('<', { x => x == "<-" || x == "<:" || x == "<%" }, keyword)
case '>' =>
append('>', { x => x == ">:" }, keyword)
case '#' =>
newBuf append keyword("#")
prev = '#'
case '@' =>
appendWhile('@', _ != ' ', annotation)
case '\"' => iter.take(2).mkString match {
case "\"\"" => appendLiteral('\"', Iterator.empty, multiline = true)
case lit => appendLiteral('\"', lit.toIterator)
}
case '\'' =>
appendLiteral('\'', Iterator.empty)
case '`' =>
appendUntil('`', _ == '`', none)
case c if c.isUpper && keywordStart =>
appendWhile(c, !typeEnders.contains(_), typeDef)
case c if numberStart(c) =>
appendWhile(c, { x => x.isDigit || x == '.' || x == '\u0000'}, literal)
case c =>
newBuf += c; prev = c
}
}
}
def eolComment() = {
newBuf append (CommentColor + "//")
var curr = '/'
while (curr != '\n' && iter.hasNext) {
curr = iter.next
newBuf += curr
}
prev = curr
newBuf append NoColor
}
def blockComment() = {
newBuf append (CommentColor + "/*")
var curr = '*'
var open = 1
while (open > 0 && iter.hasNext) {
curr = iter.next
newBuf += curr
if (curr == '*' && iter.hasNext) {
curr = iter.next
newBuf += curr
if (curr == '/') open -= 1
} else if (curr == '/' && iter.hasNext) {
curr = iter.next
newBuf += curr
if (curr == '*') open += 1
}
}
prev = curr
newBuf append NoColor
}
def appendLiteral(delim: Char, succ: Iterator[Char], multiline: Boolean = false) = {
var curr: Char = 0
var continue = true
var closing = 0
val inInterpolation = interpolationPrefixes.contains(prev)
newBuf append (LiteralColor + delim)
def shouldInterpolate =
inInterpolation && curr == '$' && prev != '$' && (iter.hasNext || succ.hasNext)
def interpolate() = {
val next: Char = if (succ.hasNext) succ.next else iter.next
if (next == '$') {
newBuf += curr
newBuf += next
prev = '$'
} else if (next == '{') {
newBuf append (KeywordColor + curr)
newBuf += next
if (iter.hasNext) {
var c = iter.next
while (iter.hasNext && c != '}') {
newBuf += c
c = iter.next
}
newBuf += c
newBuf append LiteralColor
}
} else {
newBuf append (KeywordColor + curr)
newBuf += next
var c: Char = 'a'
while (c.isLetterOrDigit && (iter.hasNext || succ.hasNext)) {
c = if (succ.hasNext) succ.next else iter.next
if (c != '"') newBuf += c
}
newBuf append LiteralColor
if (c == '"') {
newBuf += c
continue = false
}
}
closing = 0
}
while (continue && (iter.hasNext || succ.hasNext)) {
curr = if(succ.hasNext) succ.next else iter.next
if (curr == '\\' && (iter.hasNext || succ.hasNext)) {
val next = if (succ.hasNext) succ.next else iter.next
newBuf append (KeywordColor + curr)
if (next == 'u') {
val code = "u" + iter.take(4).mkString
newBuf append code
} else newBuf += next
newBuf append LiteralColor
closing = 0
} else if (shouldInterpolate) {
interpolate()
} else if (curr == delim && multiline) {
closing += 1
if (closing == 3) continue = false
newBuf += curr
} else if (curr == delim) {
continue = false
newBuf += curr
} else {
newBuf += curr
closing = 0
}
}
newBuf append NoColor
prev = curr
if (succ.hasNext) {
val (dup, _) = iter.duplicate
iter = succ ++ dup
}
}
def append(c: Char, shouldHL: String => Boolean, highlight: String => String, pre: Iterator[Char] = Iterator.empty) = {
var curr: Char = 0
val sb = new StringBuilder(s"$c")
while ((pre.hasNext || iter.hasNext) && curr != ' ' && curr != '(') {
curr = if (pre.hasNext) pre.next else iter.next
if (curr != ' ') sb += curr
}
val str = sb.toString
val toAdd = if (shouldHL(str)) highlight(str) else str
val suffix = if (curr == ' ') " " else ""
newBuf append (toAdd + suffix)
prev = curr
}
def appendWhile(c: Char, pred: Char => Boolean, highlight: String => String) = {
var curr: Char = 0
val sb = new StringBuilder(s"$c")
while (iter.hasNext && pred(curr)) {
curr = iter.next
if (pred(curr)) sb += curr
}
val str = sb.toString
val suffix = if (!pred(curr)) s"$curr" else ""
newBuf append (highlight(str) + suffix)
prev = curr
}
def appendUntil(c: Char, pred: Char => Boolean, highlight: String => String) = {
var curr: Char = 0
val sb = new StringBuilder(s"$c")
while (iter.hasNext && !pred(curr)) {
curr = iter.next
sb += curr
}
newBuf append (highlight(sb.toString))
prev = curr
}
newBuf.toVector
}
}