Angular boolean filter

boolean-filter.js

angular
  .module("app.filters", [])
  .filter("booleanSearch", booleanSearch)

function booleanSearch() {
  return function(rows, search, fields) {
    if (typeof search === "undefined") {
      return rows;
    }

    var exprs = search.split(/\s+/);

    var matchesLength = 0;
    var includesLength = 0;
    var excludesLength = 0;
    for (var i = 0; i < exprs.length; i++) {
      var expr = exprs[i].replace("+", "").replace("-", "");
      var prefix = exprs[i].charAt(0);

      if (expr == "") {
        continue;
      }

      switch (prefix) {
        case "+":
          includesLength++;
          break;
        case "-":
          excludesLength++;
          break;
        default:
          matchesLength++;
      }
    }

    var results = [];
    for (var i = 0; i < rows.length; i++) {
      var row = rows[i];
      var found = false;

      rows[i].matches = 0;
      rows[i].includes = 0;
      rows[i].excludes = 0;

      for (var j = 0; j < exprs.length; j++) {
        var expr = exprs[j].replace("+", "").replace("-", "");
        var prefix = exprs[j].charAt(0);
        var match = false;
        var include = false;
        var exclude = false;

        if (expr == "") {
          continue;
        }

        for (var k in row) {
          if (typeof fields !== "undefined") {
            if (fields.indexOf(k) < 0) {
              continue;
            }
          }
          var val = row[k].toString();

          if (val.toLowerCase().indexOf(expr.toLowerCase()) !== -1) {
            switch (prefix) {
              case "+":
                include = true;
                break;
              case "-":
                exclude = true;
                break;
              default:
                match = true;
            }
          }
        }

        if (match) {
          rows[i].matches++;
        }

        if (include) {
          rows[i].includes++;
        }

        if (exclude) {
          rows[i].excludes++;
        }
      }

      if ((rows[i].matches > 0 || matchesLength == 0) && rows[i].includes == includesLength && rows[i].excludes == 0) {
        results.push(row);
      }
    }

    return results;
  };
}

Allows for boolean +word -word searches, takes arguments search and which fields to filter on. If fields is left undefined it assumes all fields.