Allow where as alias for filter

Author: jberkel

CHANGELOG.md

@@ -4,6 +4,7 @@
 * Fixed SQLCipher integration with read-only databases ([#559][])
 * Preliminary Swift Package Manager support ([#548][], [#560][])
 * Fixed null pointer when fetching an empty BLOB ([#561][])
+* Allow `where` as alias for `filter` ([#571][])
 
 0.11.1 (06-12-2016), [diff][diff-0.11.1]
 ========================================
@@ -30,3 +31,4 @@
 [#559]: https://github.com/stephencelis/SQLite.swift/pull/559
 [#560]: https://github.com/stephencelis/SQLite.swift/pull/560
 [#561]: https://github.com/stephencelis/SQLite.swift/issues/561
+[#571]: https://github.com/stephencelis/SQLite.swift/issues/571

Documentation/Index.md

@@ -755,8 +755,12 @@ users.filter(verified || balance >= 10_000)
 
 We can build our own boolean expressions by using one of the many [filter operators and functions](#filter-operators-and-functions).
 
-> _Note:_ SQLite.swift defines `filter` instead of `where` because `where` is [a reserved keyword](https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/LexicalStructure.html#//apple_ref/doc/uid/TP40014097-CH30-ID413).
+Instead of `filter` we can also use the `where` function which is an alias:
 
+``` swift
+users.where(id == 1)
+// SELECT * FROM "users" WHERE ("id" = 1)
+```
 
 ##### Filter Operators and Functions
 

Sources/SQLite/Typed/Query.swift

@@ -306,6 +306,18 @@ extension QueryType {
         return query
     }
 
+    /// Adds a condition to the query’s `WHERE` clause.
+    /// This is an alias for `filter(predicate)`
+    public func `where`(_ predicate: Expression<Bool>) -> Self {
+        return `where`(Expression<Bool?>(predicate))
+    }
+
+    /// Adds a condition to the query’s `WHERE` clause.
+    /// This is an alias for `filter(predicate)`
+    public func `where`(_ predicate: Expression<Bool?>) -> Self {
+        return filter(predicate)
+    }
+
     // MARK: GROUP BY
 
     /// Sets a `GROUP BY` clause on the query.

Tests/SQLiteTests/QueryTests.swift

@@ -8,6 +8,7 @@ class QueryTests : XCTestCase {
     let email = Expression<String>("email")
     let age = Expression<Int?>("age")
     let admin = Expression<Bool>("admin")
+    let optionalAdmin = Expression<Bool?>("admin")
 
     let posts = Table("posts")
     let userId = Expression<Int64>("user_id")
@@ -88,6 +89,34 @@ class QueryTests : XCTestCase {
         AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 1)", users.filter(admin == true))
     }
 
+    func test_filter_compilesWhereClause_false() {
+        AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 0)", users.filter(admin == false))
+    }
+
+    func test_filter_compilesWhereClause_optional() {
+        AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 1)", users.filter(optionalAdmin == true))
+    }
+
+    func test_filter_compilesWhereClause_optional_false() {
+        AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 0)", users.filter(optionalAdmin == false))
+    }
+
+    func test_where_compilesWhereClause() {
+        AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 1)", users.where(admin == true))
+    }
+
+    func test_where_compilesWhereClause_false() {
+        AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 0)", users.where(admin == false))
+    }
+
+    func test_where_compilesWhereClause_optional() {
+        AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 1)", users.where(optionalAdmin == true))
+    }
+
+    func test_where_compilesWhereClause_optional_false() {
+        AssertSQL("SELECT * FROM \"users\" WHERE (\"admin\" = 0)", users.where(optionalAdmin == false))
+    }
+
     func test_filter_whenChained_compilesAggregateWhereClause() {
         AssertSQL(
             "SELECT * FROM \"users\" WHERE ((\"age\" >= 35) AND \"admin\")",