Play Framework/Scala example source code file (SqlStatementParser.scala)

This example Play Framework source code file (SqlStatementParser.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Play Framework (and Scala) source code examples by using tags.

All credit for the original source code belongs to Play Framework; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Play Framework tags/keywords

cntrl, javatokenparsers, list, none, option, parse, parser, play, play framework, some, sqlstatementparser, string, utilities

The SqlStatementParser.scala Play Framework example source code

/*
 * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
 */
package anorm

import scala.language.postfixOps

import scala.util.parsing.combinator._

/** Parser for SQL statement. */
object SqlStatementParser extends JavaTokenParsers {

  /**
   * Returns updated statement and associated parameter names.
   * Extracts parameter names from {placeholder}s, replaces with ?.
   *
   * {{{
   * import anorm.SqlStatementParser.parse
   *
   * val parsed: (String, List[String]) =
   *   parse("SELECT * FROM schema.table WHERE name = {name} AND cat = ?")
   * // parsed ==
   * //   ("SELECT * FROM schema.table WHERE name = ? AND cat = ?" ->
   * //    List("name"))
   * }}}
   */
  def parse(sql: String): (String, List[String]) = {
    val r = parse(instr, sql.trim().replace("\r", "").replace("\n", " ")).get
    (r.flatMap(_._1).mkString, (r.flatMap(_._2)))
  }

  private val instr: Parser[List[(String, Option[String])]] =
    rep(literal | variable | other)

  private val literal: Parser[(String, Option[String])] =
    (stringLiteral | simpleQuotes) ^^ { case s => (s, None) }

  private val variable = "{" ~> (ident ~ (("." ~> ident)?)) <~ "}" ^^ {
    case i1 ~ i2 => ("%s": String, Some(i1 + i2.map("." + _).getOrElse("")))
  }

  private val other: Parser[(String, Option[String])] = """.""".r ^^ {
    case element => (element, None)
  }

  private val simpleQuotes =
    ("'" + """([^'\p{Cntrl}\\]|\\[\\/bfnrt]|\\u[a-fA-F0-9]{4})*""" + "'").r

  override def skipWhitespace = false
}