Merge branch 'master' into errors-logs-improvements

Sources/Expression.swift

@@ -105,6 +105,10 @@ final class InExpression: Expression, InfixOperator, CustomStringConvertible {
 
       if let lhs = lhsValue as? AnyHashable, let rhs = rhsValue as? [AnyHashable] {
         return rhs.contains(lhs)
+      } else if let lhs = lhsValue as? Int, let rhs = rhsValue as? CountableClosedRange<Int> {
+        return rhs.contains(lhs)
+      } else if let lhs = lhsValue as? Int, let rhs = rhsValue as? CountableRange<Int> {
+        return rhs.contains(lhs)
       } else if let lhs = lhsValue as? String, let rhs = rhsValue as? String {
         return rhs.contains(lhs)
       } else if lhsValue == nil && rhsValue == nil {

Sources/Extension.swift

@@ -57,6 +57,8 @@ class DefaultExtension: Extension {
     registerFilter("uppercase", filter: uppercase)
     registerFilter("lowercase", filter: lowercase)
     registerFilter("join", filter: joinFilter)
+    registerFilter("split", filter: splitFilter)
+    registerFilter("indent", filter: indentFilter)
   }
 }
 

Sources/Filters.swift

@@ -1,13 +1,25 @@
 func capitalise(_ value: Any?) -> Any? {
-  return stringify(value).capitalized
+  if let array = value as? [Any?] {
+    return array.map { stringify($0).capitalized }
+  } else {
+    return stringify(value).capitalized
+  }
 }
 
 func uppercase(_ value: Any?) -> Any? {
-  return stringify(value).uppercased()
+  if let array = value as? [Any?] {
+    return array.map { stringify($0).uppercased() }
+  } else {
+    return stringify(value).uppercased()
+  }
 }
 
 func lowercase(_ value: Any?) -> Any? {
-  return stringify(value).lowercased()
+  if let array = value as? [Any?] {
+    return array.map { stringify($0).lowercased() }
+  } else {
+    return stringify(value).lowercased()
+  }
 }
 
 func defaultFilter(value: Any?, arguments: [Any?]) -> Any? {
@@ -40,3 +52,62 @@ func joinFilter(value: Any?, arguments: [Any?]) throws -> Any? {
 
   return value
 }
+
+func splitFilter(value: Any?, arguments: [Any?]) throws -> Any? {
+  guard arguments.count < 2 else {
+    throw TemplateSyntaxError("'split' filter takes a single argument")
+  }
+
+  let separator = stringify(arguments.first ?? " ")
+  if let value = value as? String {
+    return value.components(separatedBy: separator)
+  }
+
+  return value
+}
+
+func indentFilter(value: Any?, arguments: [Any?]) throws -> Any? {
+  guard arguments.count <= 3 else {
+    throw TemplateSyntaxError("'indent' filter can take at most 3 arguments")
+  }
+
+  var indentWidth = 4
+  if arguments.count > 0 {
+    guard let value = arguments[0] as? Int else {
+      throw TemplateSyntaxError("'indent' filter width argument must be an Integer (\(String(describing: arguments[0])))")
+    }
+    indentWidth = value
+  }
+
+  var indentationChar = " "
+  if arguments.count > 1 {
+    guard let value = arguments[1] as? String else {
+      throw TemplateSyntaxError("'indent' filter indentation argument must be a String (\(String(describing: arguments[1]))")
+    }
+    indentationChar = value
+  }
+
+  var indentFirst = false
+  if arguments.count > 2 {
+    guard let value = arguments[2] as? Bool else {
+      throw TemplateSyntaxError("'indent' filter indentFirst argument must be a Bool")
+    }
+    indentFirst = value
+  }
+
+  let indentation = [String](repeating: indentationChar, count: indentWidth).joined(separator: "")
+  return indent(stringify(value), indentation: indentation, indentFirst: indentFirst)
+}
+
+
+func indent(_ content: String, indentation: String, indentFirst: Bool) -> String {
+  guard !indentation.isEmpty else { return content }
+
+  var lines = content.components(separatedBy: .newlines)
+  let firstLine = (indentFirst ? indentation : "") + lines.removeFirst()
+  let result = lines.reduce([firstLine]) { (result, line) in
+    return result + [(line.isEmpty ? "" : "\(indentation)\(line)")]
+  }
+  return result.joined(separator: "\n")
+}
+

Sources/ForTag.swift

@@ -11,25 +11,28 @@ class ForNode : NodeType {
   class func parse(_ parser:TokenParser, token:Token) throws -> NodeType {
     let components = token.components()
 
-    guard components.count >= 3 && components[2] == "in" &&
-      (components.count == 4 || (components.count >= 6 && components[4] == "where")) else {
-        throw TemplateSyntaxError("'for' statements should use the following syntax 'for x in y where condition'.")
+    func hasToken(_ token: String, at index: Int) -> Bool {
+      return components.count > (index + 1) && components[index] == token
+    }
+
+    func endsOrHasToken(_ token: String, at index: Int) -> Bool {
+      return components.count == index || hasToken(token, at: index)
+    }
+
+    guard hasToken("in", at: 2) && endsOrHasToken("where", at: 4) else {
+      throw TemplateSyntaxError("'for' statements should use the syntax: `for <x> in <y> [where <condition>]`.")
     }
 
     let loopVariables = components[1].characters
       .split(separator: ",")
       .map(String.init)
-      .map { $0.trimmingCharacters(in: CharacterSet.whitespaces) }
+      .map { $0.trim(character: " ") }
 
-    let variable = components[3]
-    let filter = try parser.compileFilter(variable, containedIn: token)
+    let resolvable = try parser.compileResolvable(components[3], containedIn: token)
 
-    let `where`: Expression?
-    if components.count >= 6 {
-      `where` = try parseExpression(components: Array(components.suffix(from: 5)), tokenParser: parser, token: token)
-    } else {
-      `where` = nil
-    }
+    let `where` = hasToken("where", at: 4)
+        ? try parseExpression(components: Array(components.suffix(from: 5)), tokenParser: parser, token: token)
+        : nil
 
     let forNodes = try parser.parse(until(["endfor", "empty"]))
 
@@ -43,7 +46,7 @@ class ForNode : NodeType {
       _ = parser.nextToken()
     }
 
-    return ForNode(resolvable: filter, loopVariables: loopVariables, nodes: forNodes, emptyNodes:emptyNodes, where: `where`, token: token)
+    return ForNode(resolvable: resolvable, loopVariables: loopVariables, nodes: forNodes, emptyNodes:emptyNodes, where: `where`, token: token)
   }
 
   init(resolvable: Resolvable, loopVariables: [String], nodes:[NodeType], emptyNodes:[NodeType], where: Expression? = nil, token: Token? = nil) {
@@ -55,25 +58,26 @@ class ForNode : NodeType {
     self.token = token
   }
 
-  func push<Result>(value: Any, context: Context, closure: () throws -> (Result)) rethrows -> Result {
+  func push<Result>(value: Any, context: Context, closure: () throws -> (Result)) throws -> Result {
     if loopVariables.isEmpty {
       return try context.push() {
         return try closure()
       }
     }
 
-    if let value = value as? (Any, Any) {
-      let first = loopVariables[0]
-
-      if loopVariables.count == 2 {
-        let second = loopVariables[1]
-
-        return try context.push(dictionary: [first: value.0, second: value.1]) {
-          return try closure()
-        }
+    let valueMirror = Mirror(reflecting: value)
+    if case .tuple? = valueMirror.displayStyle {
+      if loopVariables.count > Int(valueMirror.children.count) {
+        throw TemplateSyntaxError("Tuple '\(value)' has less values than loop variables")
       }
+      var variablesContext = [String: Any]()
+      valueMirror.children.prefix(loopVariables.count).enumerated().forEach({ (offset, element) in
+        if loopVariables[offset] != "_" {
+          variablesContext[loopVariables[offset]] = element.value
+        }
+      })
 
-      return try context.push(dictionary: [first: value.0]) {
+      return try context.push(dictionary: variablesContext) {
         return try closure()
       }
     }
@@ -133,14 +137,15 @@ class ForNode : NodeType {
           "last": index == (count - 1),
           "counter": index + 1,
           "counter0": index,
-          ]
+          "length": count
+        ]
 
         return try context.push(dictionary: ["forloop": forContext]) {
           return try push(value: item, context: context) {
             try renderNodes(nodes, context)
           }
         }
-        }.joined(separator: "")
+      }.joined(separator: "")
     }
 
     return try context.push {

Sources/IfTag.swift

@@ -111,7 +111,7 @@ final class IfExpressionParser {
         }
       }
 
-      return .variable(try tokenParser.compileFilter(component, containedIn: token))
+      return .variable(try tokenParser.compileResolvable(component, containedIn: token))
     }
   }
 

Sources/Include.swift

@@ -3,20 +3,22 @@ import PathKit
 
 class IncludeNode : NodeType {
   let templateName: Variable
+  let includeContext: String?
   let token: Token?
 
   class func parse(_ parser: TokenParser, token: Token) throws -> NodeType {
     let bits = token.components()
 
-    guard bits.count == 2 else {
-      throw TemplateSyntaxError("'include' tag takes one argument, the template file to be included")
+    guard bits.count == 2 || bits.count == 3 else {
+      throw TemplateSyntaxError("'include' tag requires one argument, the template file to be included. A second optional argument can be used to specify the context that will be passed to the included file")
     }
 
-    return IncludeNode(templateName: Variable(bits[1]), token: token)
+    return IncludeNode(templateName: Variable(bits[1]), includeContext: bits.count == 3 ? bits[2] : nil, token: token)
   }
 
-  init(templateName: Variable, token: Token) {
+  init(templateName: Variable, includeContext: String? = nil, token: Token) {
     self.templateName = templateName
+    self.includeContext = includeContext
     self.token = token
   }
 
@@ -28,7 +30,8 @@ class IncludeNode : NodeType {
     let template = try context.environment.loadTemplate(name: templateName)
 
     do {
-      return try context.push {
+      let subContext = includeContext.flatMap { context[$0] as? [String: Any] }
+      return try context.push(dictionary: subContext) {
         return try template.render(context)
       }
     } catch {

Sources/KeyPath.swift

@@ -0,0 +1,112 @@
+import Foundation
+
+/// A structure used to represent a template variable, and to resolve it in a given context.
+final class KeyPath {
+  private var components = [String]()
+  private var current = ""
+  private var partialComponents = [String]()
+  private var subscriptLevel = 0
+
+  let variable: String
+  let context: Context
+
+  // Split the keypath string and resolve references if possible
+  init(_ variable: String, in context: Context) {
+    self.variable = variable
+    self.context = context
+  }
+
+  func parse() throws -> [String] {
+    defer {
+      components = []
+      current = ""
+      partialComponents = []
+      subscriptLevel = 0
+    }
+
+    for c in variable.characters {
+      switch c {
+      case "." where subscriptLevel == 0:
+        try foundSeparator()
+      case "[":
+        try openBracket()
+      case "]":
+        try closeBracket()
+      default:
+        try addCharacter(c)
+      }
+    }
+    try finish()
+
+    return components
+  }
+
+  private func foundSeparator() throws {
+    if !current.isEmpty {
+      partialComponents.append(current)
+    }
+
+    guard !partialComponents.isEmpty else {
+      throw TemplateSyntaxError("Unexpected '.' in variable '\(variable)'")
+    }
+
+    components += partialComponents
+    current = ""
+    partialComponents = []
+  }
+
+  // when opening the first bracket, we must have a partial component
+  private func openBracket() throws {
+    guard !partialComponents.isEmpty || !current.isEmpty else {
+      throw TemplateSyntaxError("Unexpected '[' in variable '\(variable)'")
+    }
+
+    if subscriptLevel > 0 {
+      current.append("[")
+    } else if !current.isEmpty {
+      partialComponents.append(current)
+      current = ""
+    }
+
+    subscriptLevel += 1
+  }
+
+  // for a closing bracket at root level, try to resolve the reference
+  private func closeBracket() throws {
+    guard subscriptLevel > 0 else {
+      throw TemplateSyntaxError("Unbalanced ']' in variable '\(variable)'")
+    }
+
+    if subscriptLevel > 1 {
+      current.append("]")
+    } else if !current.isEmpty,
+      let value = try Variable(current).resolve(context) {
+      partialComponents.append("\(value)")
+      current = ""
+    } else {
+      throw TemplateSyntaxError("Unable to resolve subscript '\(current)' in variable '\(variable)'")
+    }
+
+    subscriptLevel -= 1
+  }
+
+  private func addCharacter(_ c: Character) throws {
+    guard partialComponents.isEmpty || subscriptLevel > 0 else {
+      throw TemplateSyntaxError("Unexpected character '\(c)' in variable '\(variable)'")
+    }
+
+    current.append(c)
+  }
+
+  private func finish() throws {
+    // check if we have a last piece
+    if !current.isEmpty {
+      partialComponents.append(current)
+    }
+    components += partialComponents
+
+    guard subscriptLevel == 0 else {
+      throw TemplateSyntaxError("Unbalanced subscript brackets in variable '\(variable)'")
+    }
+  }
+}

Sources/Lexer.swift

@@ -14,7 +14,12 @@ struct Lexer {
       guard string.characters.count > 4 else { return "" }
       let start = string.index(string.startIndex, offsetBy: 2)
       let end = string.index(string.endIndex, offsetBy: -2)
-      return String(string[start..<end]).trim(character: " ")
+      let trimmed = String(string[start..<end])
+        .components(separatedBy: "\n")
+        .filter({ !$0.isEmpty })
+        .map({ $0.trim(character: " ") })
+        .joined(separator: " ")
+      return trimmed
     }
 
     if string.hasPrefix("{{") || string.hasPrefix("{%") || string.hasPrefix("{#") {

Sources/Node.swift

@@ -79,6 +79,8 @@ public class VariableNode : NodeType {
 func stringify(_ result: Any?) -> String {
   if let result = result as? String {
     return result
+  } else if let array = result as? [Any?] {
+    return unwrap(array).description
   } else if let result = result as? CustomStringConvertible {
     return result.description
   } else if let result = result as? NSObject {
@@ -87,3 +89,16 @@ func stringify(_ result: Any?) -> String {
 
   return ""
 }
+
+func unwrap(_ array: [Any?]) -> [Any] {
+  return array.map { (item: Any?) -> Any in
+    if let item = item {
+      if let items = item as? [Any?] {
+        return unwrap(items)
+      } else {
+        return item
+      }
+    }
+    else { return item as Any }
+  }
+}

Sources/Parser.swift

@@ -40,7 +40,7 @@ public class TokenParser {
       case .text(let text, _):
         nodes.append(TextNode(text: text))
       case .variable:
-        let filter = try compileFilter(token.contents, containedIn: token)
+        let filter = try compileResolvable(token.contents, containedIn: token)
         nodes.append(VariableNode(variable: filter, token: token))
       case .block:
         if let parse_until = parse_until , parse_until(self, token) {
@@ -94,7 +94,26 @@ public class TokenParser {
       }
     }
 
-    throw TemplateSyntaxError("Unknown filter '\(name)'")
+    let suggestedFilters = self.suggestedFilters(for: name)
+    if suggestedFilters.isEmpty {
+      throw TemplateSyntaxError("Unknown filter '\(name)'.")
+    } else {
+      throw TemplateSyntaxError("Unknown filter '\(name)'. Found similar filters: \(suggestedFilters.map({ "'\($0)'" }).joined(separator: ", ")).")
+    }
+  }
+
+  private func suggestedFilters(for name: String) -> [String] {
+    let allFilters = environment.extensions.flatMap({ $0.filters.keys })
+
+    let filtersWithDistance = allFilters
+                .map({ (filterName: $0, distance: $0.levenshteinDistance(name)) })
+                // do not suggest filters which names are shorter than the distance
+                .filter({ $0.filterName.characters.count > $0.distance })
+    guard let minDistance = filtersWithDistance.min(by: { $0.distance < $1.distance })?.distance else {
+      return []
+    }
+    // suggest all filters with the same distance
+    return filtersWithDistance.filter({ $0.distance == minDistance }).map({ $0.filterName })
   }
 
   public func compileFilter(_ filterToken: String, containedIn containingToken: Token) throws -> Resolvable {
@@ -122,4 +141,57 @@ public class TokenParser {
     return try FilterExpression(token: token, parser: self)
   }
 
+  @available(*, deprecated, message: "Use compileResolvable(_:containedIn:)")
+  public func compileResolvable(_ token: String) throws -> Resolvable {
+    return try RangeVariable(token, parser: self)
+      ?? compileFilter(token)
+  }
+
+  public func compileResolvable(_ token: String, containedIn containingToken: Token) throws -> Resolvable {
+    return try RangeVariable(token, parser: self)
+        ?? compileFilter(token, containedIn: containingToken)
+  }
+
+}
+
+// https://en.wikipedia.org/wiki/Levenshtein_distance#Iterative_with_two_matrix_rows
+extension String {
+
+  subscript(_ i: Int) -> Character {
+    return self[self.index(self.startIndex, offsetBy: i)]
+  }
+
+  func levenshteinDistance(_ target: String) -> Int {
+    // create two work vectors of integer distances
+    var last, current: [Int]
+
+    // initialize v0 (the previous row of distances)
+    // this row is A[0][i]: edit distance for an empty s
+    // the distance is just the number of characters to delete from t
+    last = [Int](0...target.characters.count)
+    current = [Int](repeating: 0, count: target.characters.count + 1)
+
+    for i in 0..<self.characters.count {
+      // calculate v1 (current row distances) from the previous row v0
+
+      // first element of v1 is A[i+1][0]
+      //   edit distance is delete (i+1) chars from s to match empty t
+      current[0] = i + 1
+
+      // use formula to fill in the rest of the row
+      for j in 0..<target.characters.count {
+        current[j+1] = Swift.min(
+          last[j+1] + 1,
+          current[j] + 1,
+          last[j] + (self[i] == target[j] ? 0 : 1)
+        )
+      }
+
+      // copy v1 (current row) to v0 (previous row) for next iteration
+      last = current
+    }
+
+    return current[target.characters.count]
+  }
+
 }

Sources/Tokenizer.swift

@@ -10,6 +10,21 @@ extension String {
     var singleQuoteCount = 0
     var doubleQuoteCount = 0
 
+    let specialCharacters = ",|:"
+    func appendWord(_ word: String) {
+      if components.count > 0 {
+        if let precedingChar = components.last?.characters.last, specialCharacters.characters.contains(precedingChar) {
+          components[components.count-1] += word
+        } else if specialCharacters.contains(word) {
+          components[components.count-1] += word
+        } else {
+          components.append(word)
+        }
+      } else {
+        components.append(word)
+      }
+    }
+
     for character in self.characters {
       if character == "'" { singleQuoteCount += 1 }
       else if character == "\"" { doubleQuoteCount += 1 }
@@ -18,8 +33,8 @@ extension String {
 
         if separate != separator {
           word.append(separate)
-        } else if singleQuoteCount % 2 == 0 && doubleQuoteCount % 2 == 0 && !word.isEmpty {
-          components.append(word)
+        } else if (singleQuoteCount % 2 == 0 || doubleQuoteCount % 2 == 0) && !word.isEmpty {
+          appendWord(word)
           word = ""
         }
 
@@ -33,7 +48,7 @@ extension String {
     }
 
     if !word.isEmpty {
-      components.append(word)
+      appendWord(word)
     }
 
     return components

Sources/Variable.swift

@@ -48,8 +48,10 @@ public struct Variable : Equatable, Resolvable {
     self.variable = variable
   }
 
-  fileprivate func lookup() -> [String] {
-    return variable.characters.split(separator: ".").map(String.init)
+  // Split the lookup string and resolve references if possible
+  fileprivate func lookup(_ context: Context) throws -> [String] {
+    var keyPath = KeyPath(variable, in: context)
+    return try keyPath.parse()
   }
 
   /// Resolve the variable in the given context
@@ -68,8 +70,12 @@ public struct Variable : Equatable, Resolvable {
     if let number = Number(variable) {
       return number
     }
+    // Boolean literal
+    if let bool = Bool(variable) {
+      return bool
+    }
 
-    for bit in lookup() {
+    for bit in try lookup(context) {
       current = normalize(current)
 
       if let context = current as? Context {
@@ -124,6 +130,42 @@ public func ==(lhs: Variable, rhs: Variable) -> Bool {
   return lhs.variable == rhs.variable
 }
 
+/// A structure used to represet range of two integer values expressed as `from...to`.
+/// Values should be numbers (they will be converted to integers).
+/// Rendering this variable produces array from range `from...to`.
+/// If `from` is more than `to` array will contain values of reversed range.
+public struct RangeVariable: Resolvable {
+  public let from: Resolvable
+  public let to: Resolvable
+
+  public init?(_ token: String, parser: TokenParser) throws {
+    let components = token.components(separatedBy: "...")
+    guard components.count == 2 else {
+      return nil
+    }
+
+    self.from = try parser.compileFilter(components[0])
+    self.to = try parser.compileFilter(components[1])
+  }
+
+  public func resolve(_ context: Context) throws -> Any? {
+    let fromResolved = try from.resolve(context)
+    let toResolved = try to.resolve(context)
+
+    guard let from = fromResolved.flatMap(toNumber(value:)).flatMap(Int.init) else {
+      throw TemplateSyntaxError("'from' value is not an Integer (\(fromResolved ?? "nil"))")
+    }
+
+    guard let to = toResolved.flatMap(toNumber(value:)).flatMap(Int.init) else {
+      throw TemplateSyntaxError("'to' value is not an Integer (\(toResolved ?? "nil") )")
+    }
+
+    let range = min(from, to)...max(from, to)
+    return from > to ? Array(range.reversed()) : Array(range)
+  }
+
+}
+
 
 func normalize(_ current: Any?) -> Any? {
   if let current = current as? Normalizable {
@@ -167,25 +209,47 @@ extension Dictionary : Normalizable {
 
 func parseFilterComponents(token: String) -> (String, [Variable]) {
   var components = token.smartSplit(separator: ":")
-  let name = components.removeFirst()
+  let name = components.removeFirst().trim(character: " ")
   let variables = components
     .joined(separator: ":")
     .smartSplit(separator: ",")
-    .map { Variable($0) }
+    .map { Variable($0.trim(character: " ")) }
   return (name, variables)
 }
 
 extension Mirror {
   func getValue(for key: String) -> Any? {
-    let result = descendant(key)
+    let result = descendant(key) ?? Int(key).flatMap({ descendant($0) })
     if result == nil {
       // go through inheritance chain to reach superclass properties
       return superclassMirror?.getValue(for: key)
-    } else if let result = result, String(describing: result) == "nil" {
-      // mirror returns non-nil value even for nil-containing properties
-      // so we have to check if its value is actually nil or not
-      return nil
+    } else if let result = result {
+      guard String(describing: result) != "nil" else {
+        // mirror returns non-nil value even for nil-containing properties
+        // so we have to check if its value is actually nil or not
+        return nil
+      }
+      if let result = (result as? AnyOptional)?.wrapped {
+        return result
+      } else {
+        return result
+      }
     }
     return result
   }
 }
+
+protocol AnyOptional {
+  var wrapped: Any? { get }
+}
+
+extension Optional: AnyOptional {
+  var wrapped: Any? {
+    switch self {
+    case let .some(value): return value
+    case .none: return nil
+    }
+  }
+}
+
+