Implement type normalization

Sources/MacroToolkit/NormalizedType.swift

@@ -0,0 +1,128 @@
+import SwiftSyntax
+import SwiftSyntaxBuilder
+
+public enum NormalizedType: TypeProtocol, SyntaxExpressibleByStringInterpolation {
+    /// A composition of two types (e.g. `Encodable & Decodable`). Used to
+    /// combine protocol requirements.
+    case composition(NormalizedCompositionType)
+    /// A some or any protocol type (e.g. `any T` or `some T`).
+    case someOrAny(NormalizedSomeOrAnyType)
+    /// A function type (e.g. `() -> ()`).
+    case function(NormalizedFunctionType)
+    /// An implicitly unwrapped optional type (e.g. `Int!`).
+    case implicitlyUnwrappedOptional(NormalizedImplicitlyUnwrappedOptionalType)
+    /// A member type (e.g. `Array<Int>.Element`).
+    case member(NormalizedMemberType)
+    /// A placeholder for invalid types that the resilient parser ignored.
+    case missing(NormalizedMissingType)
+    /// A pack expansion type (e.g. `repeat each V`).
+    case packExpansion(NormalizedPackExpansionType)
+    /// A pack reference type (e.g. `each V`).
+    case packReference(NormalizedPackReferenceType)
+    /// A simple type (e.g. `Int` or `Box<Int>`).
+    case simple(NormalizedSimpleType)
+    /// A suppressed type in a conformance position (e.g. `~Copyable`).
+    case suppressed(NormalizedSuppressedType)
+    //// A tuple type (e.g. `(Int, String)`).
+    case tuple(NormalizedTupleType)
+
+    public var _baseSyntax: TypeSyntax {
+        let type: any TypeProtocol = switch self {
+        case .composition(let type as any TypeProtocol),
+                    .someOrAny(let type as any TypeProtocol),
+                    .function(let type as any TypeProtocol),
+                    .implicitlyUnwrappedOptional(let type as any TypeProtocol),
+                    .member(let type as any TypeProtocol),
+                    .missing(let type as any TypeProtocol),
+                    .packExpansion(let type as any TypeProtocol),
+                    .packReference(let type as any TypeProtocol),
+                    .simple(let type as any TypeProtocol),
+                    .suppressed(let type as any TypeProtocol),
+                    .tuple(let type as any TypeProtocol):
+            type
+        }
+        return TypeSyntax(type._baseSyntax)
+    }
+
+    public var _attributedSyntax: AttributedTypeSyntax? {
+        let type: any TypeProtocol = switch self {
+        case .composition(let type as any TypeProtocol),
+                    .someOrAny(let type as any TypeProtocol),
+                    .function(let type as any TypeProtocol),
+                    .implicitlyUnwrappedOptional(let type as any TypeProtocol),
+                    .member(let type as any TypeProtocol),
+                    .missing(let type as any TypeProtocol),
+                    .packExpansion(let type as any TypeProtocol),
+                    .packReference(let type as any TypeProtocol),
+                    .simple(let type as any TypeProtocol),
+                    .suppressed(let type as any TypeProtocol),
+                    .tuple(let type as any TypeProtocol):
+            type
+        }
+        return type._attributedSyntax
+    }
+
+    /// Wrap a `TypeSyntax` (e.g. `Int?` or `MyStruct<[String]>!`).
+    public init(_ syntax: TypeSyntax) {
+        self.init(syntax, attributedSyntax: nil)
+    }
+
+    public init(_ syntax: TypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        // TODO: Move this weird initializer to an internal protocol if possible
+        let syntax: TypeSyntaxProtocol = attributedSyntax ?? syntax
+        if let type = NormalizedCompositionType(syntax) {
+            self = .composition(type)
+        } else if let type = NormalizedSomeOrAnyType(syntax) {
+            self = .someOrAny(type)
+        } else if let type = NormalizedFunctionType(syntax) {
+            self = .function(type)
+        } else if let type = NormalizedImplicitlyUnwrappedOptionalType(syntax) {
+            self = .implicitlyUnwrappedOptional(type)
+        } else if let type = NormalizedMemberType(syntax) {
+            self = .member(type)
+        } else if let type = NormalizedPackExpansionType(syntax) {
+            self = .packExpansion(type)
+        } else if let type = NormalizedPackReferenceType(syntax) {
+            self = .packReference(type)
+        } else if let type = NormalizedSimpleType(syntax) {
+            self = .simple(type)
+        } else if let type = NormalizedSuppressedType(syntax) {
+            self = .suppressed(type)
+        } else if let type = NormalizedTupleType(syntax) {
+            self = .tuple(type)
+        } else {
+            fatalError("TODO: Implement wrappers for all types of type syntax")
+        }
+    }
+
+    // TODO: add an optional version to all type syntax wrappers maybe?
+    /// Allows string interpolation syntax to be used to express type syntax.
+    public init(stringInterpolation: SyntaxStringInterpolation) {
+        self.init(TypeSyntax(stringInterpolation: stringInterpolation))
+    }
+
+    /// Gets whether the type is optional
+    public var isOptional: Bool {
+        if case .simple(let simpleType) = self {
+            return simpleType.name == "Optional"
+        }
+        return false
+    }
+
+    // TODO: Generate type conversions with macro?
+    /// Attempts to get the type as a simple type.
+    public var asSimpleType: NormalizedSimpleType? {
+        switch self {
+            case .simple(let type): type
+            default: nil
+        }
+    }
+
+    /// Attempts to get the type as a function type.
+    public var asFunctionType: NormalizedFunctionType? {
+        switch self {
+            case .function(let type): type
+            default: nil
+        }
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedCompositionType.swift

@@ -0,0 +1,12 @@
+import SwiftSyntax
+
+/// Wraps a composition type (e.g. `ProtocolA & ProtocolB`).
+public struct NormalizedCompositionType: TypeProtocol {
+    public var _baseSyntax: CompositionTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(_ syntax: CompositionTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedFunctionType.swift

@@ -0,0 +1,25 @@
+import SwiftSyntax
+
+/// Wraps a function type (e.g. `(Int, Double) -> Bool`).
+public struct NormalizedFunctionType: TypeProtocol {
+    // TODO: Should give access to attributes such as `@escaping`.
+    public var _baseSyntax: FunctionTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    /// Don't supply the `attributedSyntax` parameter, use the `attributedSyntax` initializer instead.
+    /// It only exists because of protocol conformance.
+    public init(_ syntax: FunctionTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+
+    /// The return type that the function type describes.
+    public var returnType: NormalizedType {
+        NormalizedType(_baseSyntax.returnClause.type)
+    }
+
+    /// The types of the parameters the function type describes.
+    public var parameters: [NormalizedType] {
+        _baseSyntax.parameters.map(\.type).map(NormalizedType.init)
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedImplicitlyUnwrappedOptionalType.swift

@@ -0,0 +1,12 @@
+import SwiftSyntax
+
+/// Wraps an implicitly unwrapped optional type (e.g. `Int!`).
+public struct NormalizedImplicitlyUnwrappedOptionalType: TypeProtocol {
+    public var _baseSyntax: ImplicitlyUnwrappedOptionalTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(_ syntax: ImplicitlyUnwrappedOptionalTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedMemberType.swift

@@ -0,0 +1,15 @@
+import SwiftSyntax
+
+/// Wraps a member type (e.g. `Array<Int>.Element`).
+public struct NormalizedMemberType: TypeProtocol {
+    public var _baseSyntax: MemberTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(
+        _ syntax: MemberTypeSyntax,
+        attributedSyntax: AttributedTypeSyntax? = nil
+    ) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedMissingType.swift

@@ -0,0 +1,13 @@
+import SwiftSyntax
+
+/// Wraps a missing type (i.e. a type that was missing in the source but the resilient parser
+/// has added a placeholder for).
+public struct NormalizedMissingType: TypeProtocol {
+    public var _baseSyntax: MissingTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(_ syntax: MissingTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedPackExpansionType.swift

@@ -0,0 +1,12 @@
+import SwiftSyntax
+
+/// Wraps a pack expansion type (e.g. `repeat each V`).
+public struct NormalizedPackExpansionType: TypeProtocol {
+    public var _baseSyntax: PackExpansionTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(_ syntax: PackExpansionTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedPackReferenceType.swift

@@ -0,0 +1,12 @@
+import SwiftSyntax
+
+/// Wraps an implicitly unwrapped optional type (e.g. `each V`).
+public struct NormalizedPackReferenceType: TypeProtocol {
+    public var _baseSyntax: PackElementTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(_ syntax: PackElementTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedSimpleType.swift

@@ -0,0 +1,28 @@
+import SwiftSyntax
+
+/// Wraps a simple type (e.g. `Result<Success, Failure>`).
+public struct NormalizedSimpleType: TypeProtocol {
+    public var _baseSyntax: IdentifierTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(
+        _ syntax: IdentifierTypeSyntax,
+        attributedSyntax: AttributedTypeSyntax? = nil
+    ) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+
+    /// The base type's name (e.g. for `Array<Int>` it would be `"Array"`).
+    public var name: String {
+        _baseSyntax.name.description
+    }
+
+    /// The type's generic arguments if any were supplied (e.g. for
+    /// `Dictionary<Int, String>` it would be `["Int", "String"]`).
+    public var genericArguments: [NormalizedType]? {
+        _baseSyntax.genericArgumentClause.map { clause in
+            clause.arguments.map(\.argument).map(NormalizedType.init)
+        }
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedSomeOrAnyType.swift

@@ -0,0 +1,15 @@
+import SwiftSyntax
+
+/// Wraps a `some` or `any` type (i.e. `any Protocol` or `some Protocol`).
+public struct NormalizedSomeOrAnyType: TypeProtocol {
+    public var _baseSyntax: SomeOrAnyTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(
+        _ syntax: SomeOrAnyTypeSyntax,
+        attributedSyntax: AttributedTypeSyntax? = nil
+    ) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedSuppressedType.swift

@@ -0,0 +1,12 @@
+import SwiftSyntax
+
+/// Wraps a suppressed type from a conformance clause (e.g. `~Copyable`).
+public struct NormalizedSuppressedType: TypeProtocol {
+    public var _baseSyntax: SuppressedTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(_ syntax: SuppressedTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+}

Sources/MacroToolkit/NormalizedTypes/NormalizedTupleType.swift

@@ -0,0 +1,19 @@
+import SwiftSyntax
+
+/// Wraps a tuple type (e.g. `(Int, String)`).
+public struct NormalizedTupleType: TypeProtocol {
+    public var _baseSyntax: TupleTypeSyntax
+    public var _attributedSyntax: AttributedTypeSyntax?
+
+    public init(_ syntax: TupleTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+        _baseSyntax = syntax
+        _attributedSyntax = attributedSyntax
+    }
+
+    var elements: [NormalizedType] {
+        // TODO: Handle labels and the possible ellipsis
+        _baseSyntax.elements.map { element in
+            NormalizedType(element.type)
+        }
+    }
+}