From e6f38966d13dcef90e7b640e7c09daa29aff77a8 Mon Sep 17 00:00:00 2001
From: Richard Wei <rxwei@apple.com>
Date: Mon, 20 Jun 2022 00:13:31 -0700
Subject: [PATCH] Make unary builder return `Regex` type consistently.
Currently, unary regex component builder simply forwards the component's base type. However, this is inconsistent with non-unary builder results. The current behavior may lead to surprising results when the user marks a property with `@RegexComponentBuilder`.
This patch makes `RegexComponentBuilder.buildPartialBlock<R>(first: R)` return a `Regex<R.RegexOutput>` rather than `R` itself.
---
Before:
```swift
// error: cannot convert value of type 'OneOrMore<Substring>' to specified type 'Regex<Substring>'
@RegexComponentBuilder
var r: Regex<Substring> {
OneOrMore("a")
// Adding other components below will make the error go away.
}
struct MyCustomRegex: RegexComponent {
// error: cannot convert value of type 'OneOrMore<Substring>' to specified type 'Regex<Substring>'
var regex: Regex<Substring> {
OneOrMore("a")
}
}
```
After: No errors.
---
Sources/RegexBuilder/Builder.swift | 6 ++++--
Tests/RegexBuilderTests/RegexDSLTests.swift | 22 ++++++++++++++++++++-
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/Sources/RegexBuilder/Builder.swift b/Sources/RegexBuilder/Builder.swift
index a50f069ec..dfafd3803 100644
--- a/Sources/RegexBuilder/Builder.swift
+++ b/Sources/RegexBuilder/Builder.swift
@@ -18,8 +18,10 @@ public enum RegexComponentBuilder {
.init(node: .empty)
}
- public static func buildPartialBlock<R: RegexComponent>(first: R ) -> R {
- first
+ public static func buildPartialBlock<R: RegexComponent>(
+ first component: R
+ ) -> Regex<R.RegexOutput> {
+ component.regex
}
public static func buildExpression<R: RegexComponent>(_ regex: R) -> R {
diff --git a/Tests/RegexBuilderTests/RegexDSLTests.swift b/Tests/RegexBuilderTests/RegexDSLTests.swift
index 5b3914e3b..fc31e575f 100644
--- a/Tests/RegexBuilderTests/RegexDSLTests.swift
+++ b/Tests/RegexBuilderTests/RegexDSLTests.swift
@@ -1015,7 +1015,7 @@ class RegexDSLTests: XCTestCase {
XCTAssertEqual(str.wholeMatch(of: parser)?.1, version)
}
}
-
+
func testZeroWidthConsumer() throws {
struct Trace: CustomConsumingRegexComponent {
typealias RegexOutput = Void
@@ -1051,6 +1051,26 @@ class RegexDSLTests: XCTestCase {
""")
}
+
+ func testRegexComponentBuilderResultType() {
+ // Test that the user can declare a closure or computed property marked with
+ // `@RegexComponentBuilder` with `Regex` as the result type.
+ @RegexComponentBuilder
+ var unaryWithSingleNonRegex: Regex<Substring> {
+ OneOrMore("a")
+ }
+ @RegexComponentBuilder
+ var multiComponent: Regex<Substring> {
+ OneOrMore("a")
+ "b"
+ }
+ struct MyCustomRegex: RegexComponent {
+ @RegexComponentBuilder
+ var regex: Regex<Substring> {
+ OneOrMore("a")
+ }
+ }
+ }
}
extension Unicode.Scalar {