// Utility function that allows modes to be combined. The mode given // as the base argument takes care of most of the normal mode // functionality, but a second (typically simple) mode is used, which // can override the style of text. Both modes get to parse all of the // text, but when both assign a non-null style to a piece of code, the // overlay wins, unless the combine argument was true, in which case // the styles are combined.

// overlayParser is the old, deprecated name CodeMirror.overlayMode = CodeMirror.overlayParser = function(base, overlay, combine) {

return {
  startState: function() {
    return {
      base: CodeMirror.startState(base),
      overlay: CodeMirror.startState(overlay),
      basePos: 0, baseCur: null,
      overlayPos: 0, overlayCur: null
    };
  },
  copyState: function(state) {
    return {
      base: CodeMirror.copyState(base, state.base),
      overlay: CodeMirror.copyState(overlay, state.overlay),
      basePos: state.basePos, baseCur: null,
      overlayPos: state.overlayPos, overlayCur: null
    };
  },

  token: function(stream, state) {
    if (stream.start == state.basePos) {
      state.baseCur = base.token(stream, state.base);
      state.basePos = stream.pos;
    }
    if (stream.start == state.overlayPos) {
      stream.pos = stream.start;
      state.overlayCur = overlay.token(stream, state.overlay);
      state.overlayPos = stream.pos;
    }
    stream.pos = Math.min(state.basePos, state.overlayPos);
    if (stream.eol()) state.basePos = state.overlayPos = 0;

    if (state.overlayCur == null) return state.baseCur;
    if (state.baseCur != null && combine) return state.baseCur + " " + state.overlayCur;
    else return state.overlayCur;
  },

  indent: base.indent && function(state, textAfter) {
    return base.indent(state.base, textAfter);
  },
  electricChars: base.electricChars,

  innerMode: function(state) { return {state: state.base, mode: base}; },

  blankLine: function(state) {
    if (base.blankLine) base.blankLine(state.base);
    if (overlay.blankLine) overlay.blankLine(state.overlay);
  }
};

};