positionToIndex, indexToPosition methods

[danyaPostfactum]

I'm looking for the way to convert given indexes (number) to positions ({row:x,column:y} object). It's like selectionStart, selectionEnd of a textarea.
This is my horrible attempt to implement it (outside the ace):

    positionToIndex: function(position) {
      var text = editor.session.getTextRange({start:{column:0,row:0},end: position});
      return text.length;
    },

    indexToPosition: function(index) {
      var lines  = editor.session.getDocument().$lines;
      var newLineChar = editor.session.doc.getNewLineCharacter();
      var currentIndex = 0;
      for (var row = 0; row < lines.length; row ++) {
        var length = editor.session.getLine(row).length;
        if (currentIndex + length >= index) {
          return {
            row: row,
            column: index - currentIndex
          }
        }
        currentIndex += length + newLineChar.length;
      }
    },

Is there a better way to do this? What about the inclusion of these methods into the ACE ?

[faceleg]

Out of interest, what are you doing this for? (I had to do a similar thing in ACEView).

On the subject of including such functionality, I suppose they'll suggest you make an extension, as a way to ensure one only includes code used in the given situation. Sorry but I have no idea where to start with that.

[danyaPostfactum]

I'm working on intregration emmet into ace. It requres interface without row/column position. I think textarea-like ranges could be useful in some cases.

[nightwing]

I have started work on emmet some time ago but didn't finish. Here's a cleaned up version e6703dc (works except for proper tabable snippets)

We didn't want to add these functions since they can't be fast on big documents #378 and there are optimizations depending on exact usecase, but they seem to be fast enough and since they are needed frequently, its' better to add them, than have everyone to do the same work

[faceleg]

👍 I would love this to be added.

[nightwing]

opened #1173
@faceleg i will advice against removing aceRange. positionToIndex, indexToPosition methods are slow, they should be used only as a last resort

[faceleg]

@nightwing thanks for the advice, I will keep the Objective C implementations.