package dotty.tools
package dotc
package repl
package ammonite.terminal
/**
* A collection of helpers that to simpify the common case of building filters
*/
object FilterTools {
val ansiRegex = "\u001B\\[[;\\d]*."
def offsetIndex(buffer: Vector[Char], in: Int) = {
var splitIndex = 0
var length = 0
while(length < in) {
ansiRegex.r.findPrefixOf(buffer.drop(splitIndex)) match {
case None =>
splitIndex += 1
length += 1
case Some(s) =>
splitIndex += s.length
}
}
splitIndex
}
/**
* Shorthand to construct a filter in the common case where you're
* switching on the prefix of the input stream and want to run some
* transformation on the buffer/cursor
*/
def Case(s: String)
(f: (Vector[Char], Int, TermInfo) => (Vector[Char], Int)) = new Filter {
val op = new PartialFunction[TermInfo, TermAction] {
def isDefinedAt(x: TermInfo) = {
def rec(i: Int, c: LazyList[Int]): Boolean = {
if (i >= s.length) true
else if (c.head == s(i)) rec(i + 1, c.tail)
else false
}
rec(0, x.ts.inputs)
}
def apply(v1: TermInfo) = {
val (buffer1, cursor1) = f(v1.ts.buffer, v1.ts.cursor, v1)
TermState(
v1.ts.inputs.dropPrefix(s.map(_.toInt)).get,
buffer1,
cursor1
)
}
}.lift
def identifier = "Case"
}
/** Shorthand for pattern matching on [[TermState]] */
val TS = TermState
def findChunks(b: Vector[Char], c: Int) = {
val chunks = Terminal.splitBuffer(b)
// The index of the first character in each chunk
val chunkStarts = chunks.inits.map(x => x.length + x.sum).toStream.reverse
// Index of the current chunk that contains the cursor
val chunkIndex = chunkStarts.indexWhere(_ > c) match {
case -1 => chunks.length-1
case x => x - 1
}
(chunks, chunkStarts, chunkIndex)
}
def firstRow(cursor: Int, buffer: Vector[Char], width: Int) =
cursor < width && (buffer.indexOf('\n') >= cursor || buffer.indexOf('\n') == -1)
def lastRow(cursor: Int, buffer: Vector[Char], width: Int) =
(buffer.length - cursor) < width &&
(buffer.lastIndexOf('\n') < cursor || buffer.lastIndexOf('\n') == -1)
}
