Nate Cook
e68069f891
[stdlib] Allow a default for optional interpolations ( #80547 )
...
This adds an `appendInterpolation` overload to
`DefaultStringInterpolation` that includes a parameter for providing a
default string when the value to interpolate is `nil`. This allows this
kind of usage:
```swift
let age: Int? = nil
print("Your age is \(age, default: "timeless")")
// Prints "Your age is timeless"
```
The change includes an additional fixit when optional values are
interpolated, with a suggestion to use this `default:` parameter.
2025-05-07 12:47:02 -05:00
Karoy Lorentey
1241df3fab
[stdlib] String.debugDescription: Fix quoting behavior
...
`String.debugDescription` currently fails to protect the contents of
the string from combining with the opening or closing `”` characters
or one of the characters of a quoted scalar:
```swift
let s = “\u{301}A\n\u{302}B\u{70F}”
print(s.debugDescription)
// ⟹ “́A\n̂B” (characters: “́, A, \, n̂, B, ”)
```
This can make debug output difficult to read, as string contents are
allowed to spread over and pollute neighboring meta-characters.
This change fixes this by force-quoting the problematic scalars in
these cases:
```swift
let s = “\u{301}A\n\u{302}B\u{70F}”
print(s.debugDescription)
// ⟹ “\u{301}A\n\u{302}B\u{70F}”
```
Of course, Unicode scalars that don’t engage in such behavior are
still allowed to pass through unchanged:
```swift
let s = “Cafe\u{301}”
print(s.debugDescription)
// ⟹ “Café”
```
2023-01-16 01:15:39 -08:00
Brent Royal-Gordon
9bd1a26089
Implementation for SE-0228: Fix ExpressibleByStringInterpolation ( #20214 )
...
* [CodeCompletion] Restrict ancestor search to brace
This change allows ExprParentFinder to restrict certain searches for parents to just AST nodes within the nearest surrounding BraceStmt. In the string interpolation rework, BraceStmts can appear in new places in the AST; this keeps code completion from looking at irrelevant context.
NFC in this commit, but keeps code completion from crashing once TapExpr is introduced.
* Remove test relying on ExpressibleByStringInterpolation being deprecated
Since soon enough, it won’t be anymore.
* [AST] Introduce TapExpr
TapExpr allows a block of code to to be inserted between two expressions, accessing and potentially mutating the result of its subexpression before giving it to its parent expression. It’s roughly equivalent to this function:
func _tap<T>(_ value: T, do body: (inout T) throws -> Void) rethrows -> T {
var copy = value
try body(©)
return copy
}
Except that it doesn’t use a closure, so no variables are captured and no call frame is (even notionally) added.
This commit does not include tests because nothing in it actually uses TapExpr yet. It will be used by string interpolation.
* SE-0228: Fix ExpressibleByStringInterpolation
This is the bulk of the implementation of the string interpolation rework. It includes a redesigned AST node, new parsing logic, new constraints and post-typechecking code generation, and new standard library types and members.
* [Sema] Rip out typeCheckExpressionShallow()
With new string interpolation in place, it is no longer used by anything in the compiler.
* [Sema] Diagnose invalid StringInterpolationProtocols
StringInterpolationProtocol informally requires conforming types to provide at least one method with the base name “appendInterpolation” with no (or a discardable) return value and visibility at least as broad as the conforming type’s. This change diagnoses an error when a conforming type does not have a method that meets those criteria.
* [Stdlib] Fix map(String.init) source break
Some users, including some in the source compatibility suite, accidentally used init(stringInterpolationSegment:) by writing code like `map(String.init)`. Now that these intializers have been removed, the remaining initializers often end up tying during overload resolution. This change adds several overloads of `String.init(describing:)` which will break these ties in cases where the compiler previously selected `String.init(stringInterpolationSegment:)`.
* [Sema] Make callWitness() take non-mutable arrays
It doesn’t actually need to mutate them.
* [Stdlib] Improve floating-point interpolation performance
This change avoids constructing a String when interpolating a Float, Double, or Float80. Instead, we write the characters to a fixed-size buffer and then append them directly to the string’s storage.
This seems to improve performance for all three types, but especially for Double and Float80, which cannot always fit into a small string when stringified.
* [NameLookup] Improve MemberLookupTable invalidation
In rare cases usually involving generated code, an overload added by an extension in the middle of a file would not be visible below it if the type had lazy members and the same base name had already been referenced above the extension. This change essentially dirties a type’s member lookup table whenever an extension is added to it, ensuring the entries in it will be updated.
This change also includes some debugging improvements for NameLookup.
* [SILOptimizer] XFAIL dead object removal failure
The DeadObjectRemoval pass in SILOptimizer does not currently remove reworked string interpolations as well as the old design because their effects cannot be described by @_effects(readonly). That causes a test failure on Linux. This change temporarily silences that test. The SILOptimizer issue has been filed as SR-9008.
* Confess string interpolation’s source stability sins
* [Parser] Parse empty interpolations
Previously, the parser had an odd asymmetry which caused the same function to accept foo(), but reject “\()”. This change fixes the issue.
Already tested by test/Parse/try.swift, which uses this construct in one of its throwing interpolation tests.
* [Sema] Fix batch-mode-only lazy var bug
The temporary variable used by string interpolation needs to be recontextualized when it’s inserted into a synthesized getter. Fixes a compilation failure in Alamofire.
I’ll probably follow up on this bug a bit more after merging.
2018-11-02 19:16:03 -07:00
