Support generating unique uninterned symbols.

Author: objecthub

Sources/LispKit/Compiler/EvalError.swift

@@ -197,6 +197,7 @@ public enum EvalError: Int, Hashable, Codable {
   case urlAuthorityError
   case urlPrototypeInvalid
   case cannotCreatePdf
+  case cannotLoadPdf
   case invalidPDFAccessIdentifier
   case invalidPDFDocGenerationOption
   case unknownPDFAnnotationType
@@ -555,6 +556,8 @@ public enum EvalError: Int, Hashable, Codable {
         return "$0 is not a valid URL prototype for procedure $,1"
       case .cannotCreatePdf:
         return "cannot create pdf document from bytevector $0"
+      case .cannotLoadPdf:
+        return "cannot load pdf document from file $0"
       case .invalidPDFAccessIdentifier:
         return "invalid PDF access permission identifier: $0"
       case .invalidPDFDocGenerationOption:

Sources/LispKit/Primitives/DrawingLibrary_iOS.swift

@@ -2478,6 +2478,6 @@ extension UIFont {
   }
 
   private var traits: [UIFontDescriptor.TraitKey: Any] {
-      return fontDescriptor.object(forKey: .traits) as? [UIFontDescriptor.TraitKey: Any] ?? [:]
+    return fontDescriptor.object(forKey: .traits) as? [UIFontDescriptor.TraitKey: Any] ?? [:]
   }
 }

Sources/LispKit/Runtime/SymbolTable.swift

@@ -329,7 +329,7 @@ public final class SymbolTable: Sequence {
   }
 
   /// Generates a new interned symbol.
-  public func gensym(_ basename: String) -> Symbol {
+  public func gensym(_ basename: String, intern: Bool = true) -> Symbol {
     self.gensymLock.lock()
     defer {
       self.gensymLock.unlock()
@@ -339,7 +339,7 @@ public final class SymbolTable: Sequence {
       ident = basename + String(self.gensymCounter)
       self.gensymCounter &+= 1
     } while self.exists(ident)
-    return self.intern(ident)
+    return intern ? self.intern(ident) : Symbol(uninterned: ident)
   }
 
   /// Generates an interned symbol by concatenating `prefix` and `sym`.