perfectkb-yate/src/prefixFold.js

Yet Another Turtle Editor, forked from YASQE

var CodeMirror = require("codemirror"), tokenUtils = require("./tokenUtils.js");

("use strict");
var lookFor = "PREFIX ";
module.exports = {
  findFirstPrefixLine: function(cm) {
    var lastLine = cm.lastLine();
    for (var i = 0; i <= lastLine; ++i) {
      if (findFirstPrefix(cm, i) >= 0) {
        return i;
      }
    }
  }
};

function findFirstPrefix(cm, line, ch, lineText) {
  if (!ch) ch = 0;
  if (!lineText) lineText = cm.getLine(line);
  lineText = lineText.toUpperCase();
  for (var at = ch, pass = 0; ; ) {
    var found = lineText.indexOf(lookFor, at);
    if (found == -1) {
      //no prefix on this line
      if (pass == 1) break;
      pass = 1;
      at = lineText.length;
      continue;
    }
    if (pass == 1 && found < ch) break;
    var tokenType = cm.getTokenTypeAt(CodeMirror.Pos(line, found + 1));
    if (!/^(comment|string)/.test(tokenType)) return found + 1;
    if (!/(comment)/.test(tokenType)) break;
    
    //Could not find a prefix, no use looping any further. Probably invalid query
    if (at === pass) break;
  }
}

CodeMirror.registerHelper("fold", "prefix", function(cm, start) {
  var line = start.line, lineText = cm.getLine(line);

  var startCh, tokenType;

  function hasPreviousPrefix() {
    var hasPreviousPrefix = false;
    for (var i = line - 1; i >= 0; i--) {
      if (cm.getLine(i).toUpperCase().indexOf(lookFor) >= 0) {
        hasPreviousPrefix = true;
        break;
      }
    }
    return hasPreviousPrefix;
  }

  function findOpening(openCh) {
    for (var at = start.ch, pass = 0; ; ) {
      var found = at <= 0 ? -1 : lineText.lastIndexOf(openCh, at - 1);
      if (found == -1) {
        if (pass == 1) break;
        pass = 1;
        at = lineText.length;
        continue;
      }
      if (pass == 1 && found < start.ch) break;
      tokenType = cm.getTokenTypeAt(CodeMirror.Pos(line, found + 1));
      if (!/^(comment|string)/.test(tokenType)) return found + 1;
      at = found - 1;
    }
  }
  var getLastPrefixPos = function(line, ch) {
    var prefixKeywordToken = cm.getTokenAt(CodeMirror.Pos(line, ch + 1));
    if (!prefixKeywordToken || prefixKeywordToken.type != "keyword") return -1;
    var prefixShortname = tokenUtils.getNextNonWsToken(cm, line, prefixKeywordToken.end + 1);
    if (!prefixShortname || prefixShortname.type != "string-2") return -1; //missing prefix keyword shortname
    var prefixUri = tokenUtils.getNextNonWsToken(cm, line, prefixShortname.end + 1);
    if (!prefixUri || prefixUri.type != "variable-3") return -1; //missing prefix uri
    return prefixUri.end;
  };

  //only use opening prefix declaration
  if (hasPreviousPrefix()) return;
  var prefixStart = findFirstPrefix(cm, line, start.ch, lineText);

  if (prefixStart == null) return;
  var stopAt = "{"; //if this char is there, we won't have a chance of finding more prefixes
  var stopAtNextLine = false;
  var count = 1, lastLine = cm.lastLine(), end, endCh;
  var prefixEndChar = getLastPrefixPos(line, prefixStart);
  var prefixEndLine = line;

  outer:
  for (var i = line; i <= lastLine; ++i) {
    if (stopAtNextLine) break;
    var text = cm.getLine(i), pos = i == line ? prefixStart + 1 : 0;

    for (;;) {
      if (!stopAtNextLine && text.indexOf(stopAt) >= 0) stopAtNextLine = true;

      var nextPrefixDeclaration = text.toUpperCase().indexOf(lookFor, pos);

      if (nextPrefixDeclaration >= 0) {
        if ((endCh = getLastPrefixPos(i, nextPrefixDeclaration)) > 0) {
          prefixEndChar = endCh;
          prefixEndLine = i;
          pos = prefixEndChar;
        }
        pos++;
      } else {
        break;
      }
    }
  }
  return {
    from: CodeMirror.Pos(line, prefixStart + lookFor.length),
    to: CodeMirror.Pos(prefixEndLine, prefixEndChar)
  };
});