Fix argument propagation to support all attribute metadata. Support g…

…eneric metadata at config-level (via an environment).

Sources/CLFormat/Arguments.swift

@@ -46,7 +46,7 @@ open class Arguments: CustomStringConvertible {
 
   /// If this instance isn't referring to all arguments (at formatting time,
   /// nested arguments might be created, e.g. to implement the ~?/indirection
-  /// directive.
+  /// directive.)
   internal let numArgumentsLeft: Int?
 
   /// The first argument to consume.
@@ -77,6 +77,15 @@ open class Arguments: CustomStringConvertible {
     return self.args.count - self.index
   }
 
+  /// Returns new arguments inheriting all settings from the current `Arguments` object.
+  public func new(args: [Any?], numArgumentsLeft: Int? = nil) -> Self {
+    return Self(locale: self.locale,
+                tabsize: self.tabsize,
+                linewidth: self.linewidth,
+                args: args,
+                numArgumentsLeft: numArgumentsLeft)
+  }
+
   /// Returns the current first argument and sets a new first argument.
   public func setFirstArg(to f: Int? = nil) -> Int {
     let res = self.firstArg
@@ -188,7 +197,7 @@ open class Arguments: CustomStringConvertible {
   public func nextAsArguments(maxArgs: Int = Int.max) throws -> Self {
     if let arg = try self.next() {
       if let arr = self.coerceToArray(arg, capAt: maxArgs) {
-        return Self(locale: self.locale, tabsize: self.tabsize, args: arr)
+        return self.new(args: arr)
       } else {
         throw CLFormatError.expectedSequenceArgument(self.index - 1, arg)
       }

Sources/CLFormat/CLFormatConfig.swift

@@ -29,15 +29,17 @@ import Foundation
 /// directives have more complex parsing logic.
 /// 
 public struct CLFormatConfig {
-  public var makeArguments: (Locale?, Int, Int, [Any?], Int?) -> Arguments
-  public var nilRepresentation: String
+  private var makeArguments: (Locale?, Int, Int, [Any?], Int?) -> Arguments
   private var directiveParsers: [Character : DirectiveParser]
+  public var nilRepresentation: String
+  public var environment: [String : AnyClass]
 
   public init(makeArguments: @escaping (Locale?, Int, Int, [Any?], Int?) -> Arguments =
                                Arguments.init,
               nilRepresentation: String = "nil") {
     self.makeArguments = makeArguments
     self.nilRepresentation = nilRepresentation
+    self.environment = [:]
     self.directiveParsers = [:]
   }
 
@@ -50,6 +52,12 @@ public struct CLFormatConfig {
     return self.makeArguments(locale, tabsize, linewidth, args, numArgumentsLeft)
   }
 
+  /// Determines what `makeArguments` is eventually invoking.
+  public mutating func setArgumentFactory(makeArguments:
+                                        @escaping (Locale?, Int, Int, [Any?], Int?) -> Arguments) {
+    self.makeArguments = makeArguments
+  }
+
   /// Add a new directive parser to this format configuration for the given
   /// array of characters.
   public mutating func parse(_ chars: [Character], with parser: @escaping DirectiveParser) {

Sources/CLFormat/StandardDirectiveSpecifier.swift

@@ -632,25 +632,19 @@ public enum StandardDirectiveSpecifier: DirectiveSpecifier {
             let arg = try iterargs.next()
             let subitercap = try parameters.number(1) ?? Int.max
             if let obj = arg, let arr = arguments.coerceToArray(obj, capAt: subitercap) {
-              let formatted = try control.format(with:
-                                    context.config.makeArguments(
-                                      locale: arguments.locale,
-                                      tabsize: arguments.tabsize,
-                                      args: arr,
-                                      numArgumentsLeft: iterargs.left), in: .frame(res, context))
+              let formatted =
+                try control.format(with: arguments.new(args: arr, numArgumentsLeft: iterargs.left),
+                                   in: .frame(res, context))
               res += formatted.string
               if case .break = formatted {
                 break
               }
             } else if subitercap > 0 {
-              var newargs = [Any?]()
-              newargs.append(arg)
-              let formatted = try control.format(with:
-                                    context.config.makeArguments(
-                                      locale: arguments.locale,
-                                      tabsize: arguments.tabsize,
-                                      args: newargs,
-                                      numArgumentsLeft: iterargs.left), in: .frame(res, context))
+              var nas = [Any?]()
+              nas.append(arg)
+              let formatted =
+                try control.format(with: arguments.new(args: nas, numArgumentsLeft: iterargs.left),
+                                   in: .frame(res, context))
               res += formatted.string
               if case .break = formatted {
                 break