Input em-dashes with space on both sides (#77)

Fixes rdar://102987894

Author: amartini51

Sources/TSPL/TSPL.docc/LanguageGuide/CollectionTypes.md

@@ -902,7 +902,7 @@ or determining whether two sets contain all, some, or none of the same values.
 
 ### Fundamental Set Operations
 
-The illustration below depicts two sets---`a` and `b`---
+The illustration below depicts two sets --- `a` and `b` ---
 with the results of various set operations represented by the shaded regions.
 
 ![](setVennDiagram)
@@ -961,7 +961,7 @@ oddDigits.symmetricDifference(singleDigitPrimeNumbers).sorted()
 
 ### Set Membership and Equality
 
-The illustration below depicts three sets---`a`, `b` and `c`---
+The illustration below depicts three sets --- `a`, `b` and `c` ---
 with overlapping regions representing elements shared among sets.
 Set `a` is a *superset* of set `b`,
 because `a` contains all elements in `b`.

Sources/TSPL/TSPL.docc/ReferenceManual/Attributes.md

@@ -329,7 +329,7 @@ dial.dynamicallyCall(withArguments: [4, 1, 1])
 The declaration of the `dynamicallyCall(withArguments:)` method
 must have a single parameter that conforms to the
 [`ExpressibleByArrayLiteral`](https://developer.apple.com/documentation/swift/expressiblebyarrayliteral)
-protocol---like `[Int]` in the example above.
+protocol --- like `[Int]` in the example above.
 The return type can be any type.
 
 You can include labels in a dynamic method call
@@ -391,7 +391,7 @@ must be
 [`ExpressibleByStringLiteral`](https://developer.apple.com/documentation/swift/expressiblebystringliteral).
 The previous example uses [`KeyValuePairs`](https://developer.apple.com/documentation/swift/keyvaluepairs)
 as the parameter type
-so that callers can include duplicate parameter labels---
+so that callers can include duplicate parameter labels ---
 `a` and `b` appear multiple times in the call to `repeat`.
 
 If you implement both `dynamicallyCall` methods,
@@ -947,7 +947,7 @@ as discussed in <doc:Declarations#Top-Level-Code>.
 
 Apply this attribute to a stored variable property of a class.
 This attribute causes the property's setter to be synthesized with a *copy*
-of the property's value---returned by the `copyWithZone(_:)` method---instead of the
+of the property's value --- returned by the `copyWithZone(_:)` method --- instead of the
 value of the property itself.
 The type of the property must conform to the `NSCopying` protocol.
 
@@ -971,7 +971,7 @@ Applying this attribute also implies the `objc` attribute.
 
 ### objc
 
-Apply this attribute to any declaration that can be represented in Objective-C---
+Apply this attribute to any declaration that can be represented in Objective-C ---
 for example, nonnested classes, protocols,
 nongeneric enumerations (constrained to integer raw-value types),
 properties and methods (including getters and setters) of classes,

Sources/TSPL/TSPL.docc/ReferenceManual/Declarations.md

@@ -799,8 +799,8 @@ A function definition can appear inside another function declaration.
 This kind of function is known as a *nested function*.
 
 A nested function is nonescaping if it captures
-a value that's guaranteed to never escape---
-such as an in-out parameter---
+a value that's guaranteed to never escape ---
+such as an in-out parameter ---
 or passed as a nonescaping function argument.
 Otherwise, the nested function is an escaping function.
 
@@ -1529,7 +1529,7 @@ An *enumeration declaration* introduces a named enumeration type into your progr
 
 Enumeration declarations have two basic forms and are declared using the `enum` keyword.
 The body of an enumeration declared using either form contains
-zero or more values---called *enumeration cases*---
+zero or more values --- called *enumeration cases* ---
 and any number of declarations,
 including computed properties,
 instance methods, type methods, initializers, type aliases,
@@ -2208,8 +2208,8 @@ and only to members of protocols that are marked
 with the `objc` attribute. As a result, only class types can adopt and conform
 to a protocol that contains optional member requirements.
 For more information about how to use the `optional` declaration modifier
-and for guidance about how to access optional protocol members---
-for example, when you're not sure whether a conforming type implements them---
+and for guidance about how to access optional protocol members ---
+for example, when you're not sure whether a conforming type implements them ---
 see <doc:Protocols#Optional-Protocol-Requirements>.
 
 <!--
@@ -2825,8 +2825,8 @@ deinit {
 
 A deinitializer is called automatically when there are no longer any references
 to a class object, just before the class object is deallocated.
-A deinitializer can be declared only in the body of a class declaration---
-but not in an extension of a class---
+A deinitializer can be declared only in the body of a class declaration ---
+but not in an extension of a class ---
 and each class can have at most one.
 
 A subclass inherits its superclass's deinitializer,
@@ -3682,8 +3682,8 @@ that introduces the declaration.
   with the `objc` attribute. As a result, only class types can adopt and conform
   to a protocol that contains optional member requirements.
   For more information about how to use the `optional` modifier
-  and for guidance about how to access optional protocol members---
-  for example, when you're not sure whether a conforming type implements them---
+  and for guidance about how to access optional protocol members ---
+  for example, when you're not sure whether a conforming type implements them ---
   see <doc:Protocols#Optional-Protocol-Requirements>.
 
 <!--

Sources/TSPL/TSPL.docc/ReferenceManual/Patterns.md

@@ -392,12 +392,12 @@ is <#type#>
 ```
 
 The `is` pattern matches a value if the type of that value at runtime is the same as
-the type specified in the right-hand side of the `is` pattern---or a subclass of that type.
+the type specified in the right-hand side of the `is` pattern --- or a subclass of that type.
 The `is` pattern behaves like the `is` operator in that they both perform a type cast
 but discard the returned type.
 
 The `as` pattern matches a value if the type of that value at runtime is the same as
-the type specified in the right-hand side of the `as` pattern---or a subclass of that type.
+the type specified in the right-hand side of the `as` pattern --- or a subclass of that type.
 If the match succeeds,
 the type of the matched value is cast to the *pattern* specified in the right-hand side
 of the `as` pattern.

Sources/TSPL/TSPL.docc/ReferenceManual/Statements.md

@@ -92,7 +92,7 @@ for <#item#> in <#collection#> {
 ```
 
 The `makeIterator()` method is called on the *collection* expression
-to obtain a value of an iterator type---that is,
+to obtain a value of an iterator type --- that is,
 a type that conforms to the
 [`IteratorProtocol`](https://developer.apple.com/documentation/swift/iteratorprotocol) protocol.
 The program begins executing a loop
@@ -388,7 +388,7 @@ which must appear at the end of the `switch` statement.
 Although the actual execution order of pattern-matching operations,
 and in particular the evaluation order of patterns in cases, is unspecified,
 pattern matching in a `switch` statement behaves
-as if the evaluation is performed in source order---that is,
+as if the evaluation is performed in source order --- that is,
 the order in which they appear in source code.
 As a result, if multiple cases contain patterns that evaluate to the same value,
 and thus can match the value of the control expression,
@@ -434,7 +434,7 @@ you can include a default case to satisfy the requirement.
 #### Switching Over Future Enumeration Cases
 
 A *nonfrozen enumeration* is a special kind of enumeration
-that may gain new enumeration cases in the future---
+that may gain new enumeration cases in the future ---
 even after you compile and ship an app.
 Switching over a nonfrozen enumeration requires extra consideration.
 When a library's authors mark an enumeration as nonfrozen,

Sources/TSPL/TSPL.docc/ReferenceManual/Types.md

@@ -11,8 +11,8 @@ In addition to user-defined named types,
 the Swift standard library defines many commonly used named types,
 including those that represent arrays, dictionaries, and optional values.
 
-Data types that are normally considered basic or primitive in other languages---
-such as types that represent numbers, characters, and strings---
+Data types that are normally considered basic or primitive in other languages ---
+such as types that represent numbers, characters, and strings ---
 are actually named types,
 defined and implemented in the Swift standard library using structures.
 Because they're named types,
@@ -1244,7 +1244,7 @@ That is,
 the type of `x` in `var x: Int = 0` is inferred by first checking the type of `0`
 and then passing this type information up to the root (the variable `x`).
 
-In Swift, type information can also flow in the opposite direction---from the root down to the leaves.
+In Swift, type information can also flow in the opposite direction --- from the root down to the leaves.
 In the following example, for instance,
 the explicit type annotation (`: Float`) on the constant `eFloat`
 causes the numeric literal `2.71828` to have an inferred type of `Float` instead of `Double`.