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dimitribounioldimitribouniol
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Added IndexRangeExpression to determine ranges properly
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3 files changed

+176
-2
lines changed

3 files changed

+176
-2
lines changed

‎Sources/CodableDatastore/Datastore.swift‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -54,7 +54,7 @@ extension Datastore {
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return nil
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}
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public func load(_ range: any RangeExpression<IdentifierType>) async throws -> AsyncStream<CodedType> {
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public func load(_ range: any IndexRangeExpression<IdentifierType>) async throws -> AsyncStream<CodedType> {
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return AsyncStream<CodedType> { continuation in
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continuation.finish()
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}
@@ -77,7 +77,7 @@ extension Datastore where AccessMode == ReadWrite {
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extension Datastore {
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public func load<IndexedValue>(
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_ range: any RangeExpression<IdentifierType>,
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_ range: any IndexRangeExpression<IdentifierType>,
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from keypath: KeyPath<CodedType, Indexed<IndexedValue>>
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) async throws -> AsyncStream<CodedType> {
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return AsyncStream<CodedType> { continuation in

‎Sources/CodableDatastore/IndexRangeExpression.swift‎

Lines changed: 102 additions & 0 deletions
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//
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// IndexRangeExpression.swift
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// CodableDatastore
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//
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// Created by Dimitri Bouniol on 2023-06-05.
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// Copyright © 2023 Mochi Development, Inc. All rights reserved.
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//
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/// A type of bound found on either end of a range.
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public enum RangeBoundExpression<Bound: Comparable>: Equatable {
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/// The bound reaches to the extent of the set the range is within.
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case extent
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/// The bound reaches up to, but not including the given value.
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case excluding(Bound)
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/// The bound reaches through the given value.
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case including(Bound)
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}
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extension RangeBoundExpression: Sendable where Bound: Sendable { }
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/// A type that can represent a range within an index.
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public protocol IndexRangeExpression<Bound> {
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associatedtype Bound: Comparable
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/// The definition of the lower bound of the range.
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var lowerBoundExpression: RangeBoundExpression<Bound> { get }
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/// The definition of the upper bound of the range.
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var upperBoundExpression: RangeBoundExpression<Bound> { get }
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}
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/// The position relative to a range.
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public enum RangePosition: Equatable {
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/// A value appears before the range.
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case before
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/// A value appears within the range.
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case within
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/// A value appears after the range.
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case after
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}
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extension IndexRangeExpression {
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/// The position of a value relative to the range.
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func position(of value: Bound) -> RangePosition {
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switch lowerBoundExpression {
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case .extent: break
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case .excluding(let lowerBound):
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if value <= lowerBound { return .before }
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case .including(let lowerBound):
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if value < lowerBound { return .before }
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}
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switch upperBoundExpression {
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case .extent: break
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case .excluding(let upperBound):
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if value >= upperBound { return .after }
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case .including(let upperBound):
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if value > upperBound { return .after }
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}
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return .within
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}
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}
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extension Range: IndexRangeExpression {
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@inlinable
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public var lowerBoundExpression: RangeBoundExpression<Bound> { .including(lowerBound) }
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@inlinable
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public var upperBoundExpression: RangeBoundExpression<Bound> { .excluding(upperBound) }
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}
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extension ClosedRange: IndexRangeExpression {
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@inlinable
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public var lowerBoundExpression: RangeBoundExpression<Bound> { .including(lowerBound) }
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@inlinable
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public var upperBoundExpression: RangeBoundExpression<Bound> { .including(upperBound) }
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}
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extension PartialRangeUpTo: IndexRangeExpression {
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@inlinable
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public var lowerBoundExpression: RangeBoundExpression<Bound> { .extent }
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@inlinable
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public var upperBoundExpression: RangeBoundExpression<Bound> { .excluding(upperBound) }
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}
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extension PartialRangeThrough: IndexRangeExpression {
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@inlinable
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public var lowerBoundExpression: RangeBoundExpression<Bound> { .extent }
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@inlinable
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public var upperBoundExpression: RangeBoundExpression<Bound> { .including(upperBound) }
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}
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extension PartialRangeFrom: IndexRangeExpression {
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@inlinable
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public var lowerBoundExpression: RangeBoundExpression<Bound> { .including(lowerBound) }
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@inlinable
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public var upperBoundExpression: RangeBoundExpression<Bound> { .extent }
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}

‎Tests/CodableDatastoreTests/IndexRangeExpressionTests.swift‎

Lines changed: 72 additions & 0 deletions
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//
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// IndexRangeExpressionTests.swift
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// CodableDatastore
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//
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// Created by Dimitri Bouniol on 2023-06-05.
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// Copyright © 2023 Mochi Development, Inc. All rights reserved.
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//
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import XCTest
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@testable import CodableDatastore
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final class IndexRangeExpressionTests: XCTestCase {
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func testLowerBound() throws {
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func lowerBoundExpression<B>(_ range: any IndexRangeExpression<B>) -> RangeBoundExpression<B> {
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range.lowerBoundExpression
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}
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XCTAssertEqual(lowerBoundExpression(1..<2), .including(1))
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XCTAssertEqual(lowerBoundExpression(1...2), .including(1))
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XCTAssertEqual(lowerBoundExpression(..<2), .extent)
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XCTAssertEqual(lowerBoundExpression(...2), .extent)
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XCTAssertEqual(lowerBoundExpression(1...), .including(1))
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}
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func testUpperBound() throws {
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func upperBoundExpression<B>(_ range: any IndexRangeExpression<B>) -> RangeBoundExpression<B> {
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range.upperBoundExpression
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}
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XCTAssertEqual(upperBoundExpression(1..<2), .excluding(2))
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XCTAssertEqual(upperBoundExpression(1...2), .including(2))
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XCTAssertEqual(upperBoundExpression(..<2), .excluding(2))
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XCTAssertEqual(upperBoundExpression(...2), .including(2))
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XCTAssertEqual(upperBoundExpression(1...), .extent)
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}
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func testPosition() throws {
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func position<B>(of value: B, in range: some IndexRangeExpression<B>) -> RangePosition {
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range.position(of: value)
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}
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XCTAssertEqual(position(of: 0, in: 1..<3), .before)
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XCTAssertEqual(position(of: 0, in: 1...3), .before)
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XCTAssertEqual(position(of: 0, in: ..<3), .within)
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XCTAssertEqual(position(of: 0, in: ...3), .within)
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XCTAssertEqual(position(of: 0, in: 1...), .before)
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XCTAssertEqual(position(of: 1, in: 1..<3), .within)
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XCTAssertEqual(position(of: 1, in: 1...3), .within)
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XCTAssertEqual(position(of: 1, in: ..<3), .within)
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XCTAssertEqual(position(of: 1, in: ...3), .within)
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XCTAssertEqual(position(of: 1, in: 1...), .within)
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XCTAssertEqual(position(of: 2, in: 1..<3), .within)
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XCTAssertEqual(position(of: 2, in: 1...3), .within)
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XCTAssertEqual(position(of: 2, in: ..<3), .within)
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XCTAssertEqual(position(of: 2, in: ...3), .within)
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XCTAssertEqual(position(of: 2, in: 1...), .within)
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XCTAssertEqual(position(of: 3, in: 1..<3), .after)
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XCTAssertEqual(position(of: 3, in: 1...3), .within)
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XCTAssertEqual(position(of: 3, in: ..<3), .after)
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XCTAssertEqual(position(of: 3, in: ...3), .within)
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XCTAssertEqual(position(of: 3, in: 1...), .within)
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XCTAssertEqual(position(of: 4, in: 1..<3), .after)
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XCTAssertEqual(position(of: 4, in: 1...3), .after)
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XCTAssertEqual(position(of: 4, in: ..<3), .after)
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XCTAssertEqual(position(of: 4, in: ...3), .after)
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XCTAssertEqual(position(of: 4, in: 1...), .within)
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}
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}

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