Functions

The following functions are available globally.

  • Stops the program, indicating that source program uses a feature that has not yet been implemented.

    Declaration

    Swift

    public func UNIMPLEMENTED(
  _ message: @autoclosure () -> String = "not implemented",
  file: StaticString = #filePath,
  line: UInt = #line
) -> Never
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  • Causes a fatal error reporting an unexpected n, where n is a node in nodes.

    Declaration

    Swift

    public func unexpected<ID: NodeIDProtocol>(
  _ n: ID, in nodes: AST,
  file: StaticString = #filePath, line: UInt = #line
) -> Never
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Parsing

  • Returns a parser that consumes an element equal to s and returns .some(s), or returns .some(nil) if such an element can’t be consumed.

    Declaration

    Swift

    private func maybe(_ s: String) -> BuiltinFunctionParser<String?>
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  • Returns a parser that consumes and returns an element equal to s.

    Declaration

    Swift

    private func exactly(_ s: String) -> BuiltinFunctionParser<String>
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  • Returns a parser that returns the result of applying a and then b or nil if either a or b returns nil.

    Declaration

    Swift

    private func ++ <A: Sendable, B: Sendable>(
  _ a: @escaping BuiltinFunctionParser<A>, _ b: @escaping BuiltinFunctionParser<B>
) -> BuiltinFunctionParser<(A, B)>
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  • Returns a parser that returns an instance of T if it can be built by consuming the next element in the stream.

    Declaration

    Swift

    private func take<T: RawRepresentable & SendableMetatype>(
  _: T.Type
) -> BuiltinFunctionParser<T> where T.RawValue == String
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  • Returns a built-in type parsed from stream.

    Declaration

    Swift

    @Sendable
private func builtinType(_ stream: inout ArraySlice<Substring>) -> BuiltinType?
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  • Returns the longest sequence of floating-point math flags that can be parsed from stream.

    Declaration

    Swift

    @Sendable
private func mathFlags(_ stream: inout ArraySlice<Substring>) -> BuiltinFunction.MathFlags
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  • Returns an overflow behavior parsed from stream or .ignore if none can be parsed.

    Declaration

    Swift

    @Sendable
private func overflowBehavior(
  _ stream: inout ArraySlice<Substring>
) -> OverflowBehavior
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  • Parses the parameters and type of an integer arithmetic instruction with overflow reporting.

    Declaration

    Swift

    private func integerArithmeticWithOverflowTail(
  _ stream: inout ArraySlice<Substring>
) -> BuiltinType?
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  • Creates a combinator that parses tokens with the specified kind.

    Declaration

    Swift

    private func take(_ kind: Token.Kind) -> TakeKind
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  • Creates a combinator that parses name tokens with the specified value.

    Declaration

    Swift

    private func take(nameTokenWithValue value: String) -> Apply<ParserState, Token>
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  • Creates a combinator that parses attribute tokens with the specified name.

    Declaration

    Swift

    private func attribute(_ name: String) -> Apply<ParserState, Token>
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  • Creates a combinator that translates token kinds to instances of type.

    Declaration

    Swift

    private func translate<T: Sendable>(
  _ table: [Token.Kind: T]
) -> Apply<ParserState, SourceRepresentable<T>>
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  • Creates a combinator that pushes context to the parser state before applying, and pops that context afterward.

    Declaration

    Swift

    private func inContext<Base: Combinator>(
  _ context: ParserState.Context,
  apply base: Base
) -> WrapInContext<Base>
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  • Creates a combinator that applies base only if its input is not preceded by whitespaces.

    Declaration

    Swift

    private func withoutLeadingWhitespace<Base: Combinator>(
  _ base: Base
) -> Apply<ParserState, Base.Element>
where Base.Context == ParserState
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  • Creates a combinator that applies base only if its input is not preceded by newlines.

    Declaration

    Swift

    private func onSameLine<Base: Combinator>(
  _ base: Base
) -> Apply<ParserState, Base.Element>
where Base.Context == ParserState
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  • Given a collection of file and directory paths as specified on the hc command line, returns the actual source files to process.

    Paths of files in sourcePaths are unconditionally treated as Hylo source files. Paths of directories are recursively searched for .hylo files, which are considered Hylo source files; all others are treated as non-source files and are ignored.

    Declaration

    Swift

    public func sourceFiles<S>(in sourcePaths: S) throws -> [SourceFile] where S : Sequence, S.Element == URL
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  • Returns the source source files in directory.

    directory is recursively searched for files with extension e; all others are treated as non-source files and are ignored. If directory is a filename, the function returns [].

    Declaration

    Swift

    public func sourceFiles(in directory: URL, withExtension e: String) throws -> [SourceFile]
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  • Creates a type-erased container wrapping the given instance.

    Declaration

    Swift

    public prefix func ^ <T>(base: T) -> AnyTerm where T : TermProtocol
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  • Creates a constraint, suitable for type inference, requiring subtype to be a subtype of supertype.

    Warning

    For inference purposes, the result of this function must be used in place of a raw SubtypingConstraint or the type checker will get stuck.

    Declaration

    Swift

    private func inferenceConstraint(
  _ subtype: AnyType,
  isSubtypeOf supertype: AnyType,
  origin: ConstraintOrigin
) -> Constraint
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  • Creates a type-erased container wrapping the given instance.

    Declaration

    Swift

    public prefix func ^ <T>(base: T) -> AnyType where T : TypeProtocol
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  • Returns true iff lhs matches an argument list labeled by rhs.

    Declaration

    Swift

    private func accepts<S: Collection>(
  _ lhs: ArraySlice<CallableTypeParameter>,
  _ rhs: S
) -> Bool where S.Element == String?
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  • Just like Swift.precondition, but includes the full file path in the diagnostic.

    Declaration

    Swift

    func precondition(
  _ condition: @autoclosure () -> Bool,
  _ message: @autoclosure () -> String = String(),
  file: StaticString = #filePath,
  line: UInt = #line
)
    Show on GitHub

  • Just like Swift.preconditionFailure, but includes the full file path in the diagnostic.

    Declaration

    Swift

    func preconditionFailure(
  _ message: @autoclosure () -> String = String(),
  file: StaticString = #filePath,
  line: UInt = #line
) -> Never
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  • Just like Swift.fatalError, but includes the full file path in the diagnostic.

    Declaration

    Swift

    func fatalError(
  _ message: @autoclosure () -> String = String(),
  file: StaticString = #filePath,
  line: UInt = #line
) -> Never
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  • Just like Swift.assert, but includes the full file path in the diagnostic.

    Declaration

    Swift

    func assert(
  _ condition: @autoclosure () -> Bool,
  _ message: @autoclosure () -> String = String(),
  file: StaticString = #filePath,
  line: UInt = #line
)
    Show on GitHub

  • Just like Swift.assertionFailure, but includes the full file path in the diagnostic.

    Declaration

    Swift

    func assertionFailure(
  _ message: @autoclosure () -> String = String(),
  file: StaticString = #filePath,
  line: UInt = #line
)
    Show on GitHub