Use extensions methods for Dart query api (#195)

extras/integration_tests/tests/lib/database/database.dart

@@ -116,7 +116,7 @@ class Database extends _$Database {
     return transaction(() async {
       final id = user.id;
       await (delete(friendships)
-            ..where((f) => or(f.firstUser.equals(id), f.secondUser.equals(id))))
+            ..where((f) => f.firstUser.equals(id) | f.secondUser.equals(id)))
           .go();
 
       if (fail) {

moor/lib/src/dsl/columns.dart

@@ -5,36 +5,24 @@ part of 'dsl.dart';
 abstract class Column<T, S extends SqlType<T>> extends Expression<T, S> {}
 
 /// A column that stores int values.
-abstract class IntColumn extends Column<int, IntType> implements IntExpression {
-}
+abstract class IntColumn extends Column<int, IntType> {}
 
 /// A column that stores boolean values. Booleans will be stored as an integer
 /// that can either be 0 (false) or 1 (true).
 abstract class BoolColumn extends Column<bool, BoolType> {}
 
 /// A column that stores text.
-abstract class TextColumn extends Column<String, StringType> {
-  /// Whether this column matches the given pattern. For details on what patters
-  /// are valid and how they are interpreted, check out
-  /// [this tutorial](http://www.sqlitetutorial.net/sqlite-like/).
-  Expression<bool, BoolType> like(String regex);
-
-  /// Uses the given [collate] sequence when comparing this column to other
-  /// values.
-  Expression<String, StringType> collate(Collate collate);
-}
+abstract class TextColumn extends Column<String, StringType> {}
 
 /// A column that stores a [DateTime]. Times will be stored as unix timestamp
 /// and will thus have a second accuracy.
-abstract class DateTimeColumn extends Column<DateTime, DateTimeType>
-    implements DateTimeExpression {}
+abstract class DateTimeColumn extends Column<DateTime, DateTimeType> {}
 
 /// A column that stores arbitrary blobs of data as a [Uint8List].
 abstract class BlobColumn extends Column<Uint8List, BlobType> {}
 
 /// A column that stores floating point numeric values.
-abstract class RealColumn extends Column<double, RealType>
-    implements DoubleExpression {}
+abstract class RealColumn extends Column<double, RealType> {}
 
 /// A column builder is used to specify which columns should appear in a table.
 /// All of the methods defined in this class and its subclasses are not meant to
@@ -94,9 +82,10 @@ class ColumnBuilder<
   /// has been specified.
   ///
   /// Note: Unless most other methods used to declare tables, the parameter
-  /// [e] which denotes the default expression, doesn't have to be constant.
-  /// Particularly, you can use methods like [and], [or] and [not] to form
-  /// expressions here.
+  /// [e] which denotes the default expression, doesn't have to be a Dart
+  /// constant.
+  /// Particularly, you can use operators like those defined in
+  /// [BooleanExpressionOperators] to form expressions here.
   ///
   /// If you need a column that just stores a static default value, you could
   /// use this method with a [Constant]:

moor/lib/src/runtime/database.dart

@@ -470,6 +470,7 @@ abstract class GeneratedDatabase extends DatabaseConnectionUser
   /// A [Type] can't be sent across isolates. Instances of this class shouldn't
   /// be sent over isolates either, so let's keep a reference to a [Type] that
   /// definitely prohibits this.
+  // ignore: unused_field
   final Type _$dontSendThisOverIsolates = Null;
 
   /// Used by generated code

moor/lib/src/runtime/query_builder/expressions/bools.dart

@@ -1,19 +1,45 @@
 part of '../query_builder.dart';
 
 /// Returns an expression that is true iff both [a] and [b] are true.
+///
+/// This is now deprecated. Instead of `and(a, b)`, use `a & b`.
+@Deprecated('Use the operator on BooleanExpressionOperators instead')
 Expression<bool, BoolType> and(
         Expression<bool, BoolType> a, Expression<bool, BoolType> b) =>
     _AndExpression(a, b);
 
 /// Returns an expression that is true iff [a], [b] or both are true.
+///
+/// This is now deprecated. Instead of `or(a, b)`, use `a | b`;
+@Deprecated('Use the operator on BooleanExpressionOperators instead')
 Expression<bool, BoolType> or(
         Expression<bool, BoolType> a, Expression<bool, BoolType> b) =>
     _OrExpression(a, b);
 
 /// Returns an expression that is true iff [a] is not true.
+///
+/// This is now deprecated. Instead of `not(a)`, prefer to use `a.not()` now.
+@Deprecated('Use BooleanExpressionOperators.not() as a extension instead')
 Expression<bool, BoolType> not(Expression<bool, BoolType> a) =>
     _NotExpression(a);
 
+/// Defines operations on boolean values.
+extension BooleanExpressionOperators on Expression<bool, BoolType> {
+  /// Negates this boolean expression. The returned expression is true if
+  /// `this` is false, and vice versa.
+  Expression<bool, BoolType> not() => _NotExpression(this);
+
+  /// Returns an expression that is true iff both `this` and [other] are true.
+  Expression<bool, BoolType> operator &(Expression<bool, BoolType> other) {
+    return _AndExpression(this, other);
+  }
+
+  /// Returns an expression that is true if `this` or [other] are true.
+  Expression<bool, BoolType> operator |(Expression<bool, BoolType> other) {
+    return _OrExpression(this, other);
+  }
+}
+
 class _AndExpression extends _InfixOperator<bool, BoolType> {
   @override
   Expression<bool, BoolType> left, right;

moor/lib/src/runtime/query_builder/expressions/comparable.dart

@@ -1,23 +1,8 @@
 part of '../query_builder.dart';
 
-// todo: Can we replace these classes with an extension on expression?
-
-/// An [Expression] that operates on ints. Declared as a class so that we can
-/// mixin [ComparableExpr].
-abstract class IntExpression extends Expression<int, IntType>
-    implements ComparableExpr<int, IntType> {}
-
-/// An [Expression] that operates on doubles. Declared as a class so that we can
-/// mixin [ComparableExpr].
-abstract class DoubleExpression extends Expression<double, RealType>
-    implements ComparableExpr<double, RealType> {}
-
-/// An [Expression] that operates on datetimes. Declared as a class so that we
-/// can mixin [ComparableExpr].
-abstract class DateTimeExpression extends Expression<DateTime, DateTimeType>
-    implements ComparableExpr<DateTime, DateTimeType> {}
-
-mixin ComparableExpr<DT, ST extends SqlType<DT>> on Expression<DT, ST> {
+/// Defines extension functions to express comparisons in sql
+extension ComparableExpr<DT, ST extends SqlType<DT>, Comparable>
+    on Expression<DT, ST> {
   /// Returns an expression that is true if this expression is strictly bigger
   /// than the other expression.
   Expression<bool, BoolType> isBiggerThan(Expression<DT, ST> other) {

moor/lib/src/runtime/query_builder/expressions/datetimes.dart

@@ -32,17 +32,16 @@ Expression<int, IntType> second(Expression<DateTime, DateTimeType> date) =>
 
 /// A sql expression that evaluates to the current date represented as a unix
 /// timestamp. The hour, minute and second fields will be set to 0.
-const DateTimeExpression currentDate =
+const Expression<DateTime, DateTimeType> currentDate =
     _CustomDateTimeExpression("strftime('%s', CURRENT_DATE)");
 
 /// A sql expression that evaluates to the current date and time, similar to
 /// [DateTime.now]. Timestamps are stored with a second accuracy.
-const DateTimeExpression currentDateAndTime =
+const Expression<DateTime, DateTimeType> currentDateAndTime =
     _CustomDateTimeExpression("strftime('%s', CURRENT_TIMESTAMP)");
 
-class _CustomDateTimeExpression extends CustomExpression<DateTime, DateTimeType>
-    with ComparableExpr
-    implements DateTimeExpression {
+class _CustomDateTimeExpression
+    extends CustomExpression<DateTime, DateTimeType> {
   const _CustomDateTimeExpression(String content) : super(content);
 }
 

moor/lib/src/runtime/query_builder/expressions/text.dart

@@ -1,5 +1,21 @@
 part of '../query_builder.dart';
 
+/// Defines methods that operate on a column storing [String] values.
+extension StringExpressionOperators on Column<String, StringType> {
+  /// Whether this column matches the given pattern. For details on what patters
+  /// are valid and how they are interpreted, check out
+  /// [this tutorial](http://www.sqlitetutorial.net/sqlite-like/).
+  Expression<bool, BoolType> like(String regex) {
+    return _LikeOperator(this, Variable.withString(regex));
+  }
+
+  /// Uses the given [collate] sequence when comparing this column to other
+  /// values.
+  Expression<String, StringType> collate(Collate collate) {
+    return _CollateOperator(this, collate);
+  }
+}
+
 /// A `text LIKE pattern` expression that will be true if the first expression
 /// matches the pattern given by the second expression.
 class _LikeOperator extends Expression<bool, BoolType> {

moor/lib/src/runtime/query_builder/query_builder.dart

@@ -2,7 +2,10 @@
 // at runtime.
 
 import 'package:meta/meta.dart';
-import 'package:moor/moor.dart';
+// todo we're hiding the extensions because the analyzer complains about
+// ambigous extensions (once via import, once via part of), even though they're
+// the same. We should probably file a bug report.
+import 'package:moor/moor.dart' hide BooleanExpressionOperators;
 import 'package:moor/sqlite_keywords.dart';
 import 'package:moor/src/runtime/executor/stream_queries.dart';
 import 'package:moor/src/utils/single_transformer.dart';

moor/lib/src/runtime/query_builder/schema/columns.dart

@@ -124,15 +124,6 @@ class GeneratedTextColumn extends GeneratedColumn<String, StringType>
   }) : super(name, tableName, nullable,
             $customConstraints: $customConstraints, defaultValue: defaultValue);
 
-  @override
-  Expression<bool, BoolType> like(String pattern) =>
-      _LikeOperator(this, Variable<String, StringType>(pattern));
-
-  @override
-  Expression<String, StringType> collate(Collate collate) {
-    return _CollateOperator(this, collate);
-  }
-
   @override
   final String typeName = 'VARCHAR';
 
@@ -175,7 +166,6 @@ class GeneratedBoolColumn extends GeneratedColumn<bool, BoolType>
 
 /// Implementation for [IntColumn]
 class GeneratedIntColumn extends GeneratedColumn<int, IntType>
-    with ComparableExpr
     implements IntColumn {
   /// Whether this column was declared to be a primary key via a column
   /// constraint. The only way to do this in Dart is with
@@ -223,7 +213,6 @@ class GeneratedIntColumn extends GeneratedColumn<int, IntType>
 
 /// Implementation for [DateTimeColumn].
 class GeneratedDateTimeColumn extends GeneratedColumn<DateTime, DateTimeType>
-    with ComparableExpr
     implements DateTimeColumn {
   /// Used by generated code.
   GeneratedDateTimeColumn(
@@ -254,7 +243,6 @@ class GeneratedBlobColumn extends GeneratedColumn<Uint8List, BlobType>
 
 /// Implementation for [RealColumn]
 class GeneratedRealColumn extends GeneratedColumn<double, RealType>
-    with ComparableExpr
     implements RealColumn {
   /// Used by generated code
   GeneratedRealColumn(

moor/lib/src/runtime/query_builder/statements/query.dart

@@ -184,7 +184,7 @@ mixin SingleTableQueryMixin<T extends Table, D extends DataClass>
     if (whereExpr == null) {
       whereExpr = Where(predicate);
     } else {
-      whereExpr = Where(and(whereExpr.predicate, predicate));
+      whereExpr = Where(whereExpr.predicate & predicate);
     }
   }
 
@@ -221,7 +221,7 @@ mixin SingleTableQueryMixin<T extends Table, D extends DataClass>
       if (predicate == null) {
         predicate = comparison;
       } else {
-        predicate = and(predicate, comparison);
+        predicate = predicate & comparison;
       }
     }
 

moor/lib/src/runtime/query_builder/statements/select/select_with_join.dart

@@ -85,7 +85,7 @@ class JoinedSelectStatement<FirstT extends Table, FirstD extends DataClass>
     if (whereExpr == null) {
       whereExpr = Where(predicate);
     } else {
-      whereExpr = Where(and(whereExpr.predicate, predicate));
+      whereExpr = Where(whereExpr.predicate & predicate);
     }
   }
 

moor/lib/src/runtime/types/sql_types.dart

@@ -23,6 +23,10 @@ abstract class SqlType<T> {
   T mapFromDatabaseResponse(dynamic response);
 }
 
+/// A marker interface for [SqlType]s that can be compared using the comparison
+/// operators in sql.
+abstract class ComparableType {}
+
 /// A mapper for boolean values in sql. Booleans are represented as integers,
 /// where 0 means false and any other value means true.
 class BoolType extends SqlType<bool> {
@@ -77,7 +81,7 @@ class StringType extends SqlType<String> {
 }
 
 /// Maps [int] values from and to sql
-class IntType extends SqlType<int> {
+class IntType extends SqlType<int> implements ComparableType {
   /// Constant constructor used by the type system
   const IntType();
 
@@ -94,7 +98,7 @@ class IntType extends SqlType<int> {
 }
 
 /// Maps [DateTime] values from and to sql
-class DateTimeType extends SqlType<DateTime> {
+class DateTimeType extends SqlType<DateTime> implements ComparableType {
   /// Constant constructor used by the type system
   const DateTimeType();
 
@@ -123,7 +127,7 @@ class DateTimeType extends SqlType<DateTime> {
 }
 
 /// Maps [Uint8List] values from and to sql
-class BlobType extends SqlType<Uint8List> {
+class BlobType extends SqlType<Uint8List> implements ComparableType {
   /// Constant constructor used by the type system
   const BlobType();
 
@@ -142,7 +146,7 @@ class BlobType extends SqlType<Uint8List> {
 }
 
 /// Maps [double] values from and to sql
-class RealType extends SqlType<double> {
+class RealType extends SqlType<double> implements ComparableType {
   /// Constant constructor used by the type system
   const RealType();
 

moor/pubspec.yaml

@@ -9,7 +9,7 @@ authors:
 maintainer: Simon Binder (@simolus3)
 
 environment:
-  sdk: '>=2.3.0 <3.0.0'
+  sdk: '>=2.6.0 <3.0.0'
 
 dependencies:
   meta: ^1.0.0

moor/test/delete_test.dart

@@ -28,7 +28,7 @@ void main() {
 
     test('for complex components', () async {
       await (db.delete(db.users)
-            ..where((u) => or(not(u.isAwesome), u.id.isSmallerThanValue(100))))
+            ..where((u) => u.isAwesome.not() | u.id.isSmallerThanValue(100)))
           .go();
 
       verify(executor.runDelete(

moor/test/select_test.dart

@@ -66,7 +66,7 @@ void main() {
     test('with complex predicates', () {
       (db.select(db.users)
             ..where((u) =>
-                and(not(u.name.equals('Dash')), (u.id.isBiggerThanValue(12)))))
+                u.name.equals('Dash').not() & u.id.isBiggerThanValue(12)))
           .get();
 
       verify(executor.runSelect(