nodebook-nbql/lib/lodash-stmt.js

Filter query language for nodebook

// lodash statement

var _ = require('lodash'),
matchStatement,
eachStatement,
findStatement,
rejectStatements,
mergeStatements,
printStatements;

// Match Statement
matchStatement = function matchStatement(statement, match) {
  return _.every(match, function (value, key) {
    if (_.isRegExp(value)) {
      return _.has(statement, key) && value.test(statement[key]);
    } else {
      return _.has(statement, key) && value === statement[key];
    }
  });
};

// Each Statement
eachStatement = function eachStatement(statements, func, groupFunc) {
  _.each(statements, function (statement, index) {
    if (_.has(statement, 'group')) {
      if (groupFunc) {
        groupFunc(statement, index);
      } else {
        eachStatement(statement.group, func, groupFunc);
      }
    } else {
      func(statement, index);
    }
  });
};

// Recursively find if any statement in the array matches the given match object
findStatement = function findStatement(statements, match, keys) {
  return _.some(statements, function (statement) {
    if (_.has(statement, 'group')) {
      return findStatement(statement.group, match, keys);
    } else {
      return matchStatement(statement, keys ? _.pick(match, keys) : match);
    }
  });
};

// Reject Statements
rejectStatements = function rejectStatements(statements, func) {
  return _.reject(statements, function (statement, index) {
    var result;

    if (_.has(statement, 'group')) {
      statement.group = rejectStatements(statement.group, func);
      result = _.isEmpty(statement.group);
    } else {
      result = func(statement);
    }

    if (result && index === 0 && statements[index + 1] && statements[index + 1].func) {
      delete statements[index + 1].func;
    }
    return result;
  });
};

// Merge Statements
mergeStatements = function mergeStatements(/* statements */) {
  var statementsArray = _.reduce(arguments, function (array, arg) {
    if (!arg) { return array; }

    if (_.has(arg, 'statements')) {
      if (array.length !== 0 && !_.isEmpty(arg.statements)) {
        arg.statements[0].func = 'and';
      }
      array = array.concat(arg.statements);
    } else {
      if (array.length !== 0) { arg.func = 'and'; }
      array.push(arg);
    }

    return array;
  }, []);

  return {statements: statementsArray};
};

// Print statements
printStatements = function printStatements(statements, indent) {
  indent = indent || 0;
  function print(indent /* strs */) {
    var strs = [_.fill(new Array(indent), ' ').join('')].concat(Array.prototype.slice.call(arguments, 1));
    console.log.apply(this, strs);
  }
  eachStatement(statements, function single(statement) {
    print(indent, statement);
  }, function group(statement) {
    print(indent, 'group', statement.func);
    printStatements(statement.group, indent + 1);
  });
};

module.exports = {
  matchStatement: matchStatement,
  eachStatement: eachStatement,
  findStatement: findStatement,
  rejectStatements: rejectStatements,
  mergeStatements: mergeStatements,
  printStatements: printStatements
};