Merge pull request #359 from flintlang/revert-354-trait_specification…

…_contracts

Revert "Trait specification contracts"

Sources/AST/ASTDumper.swift

@@ -65,13 +65,6 @@ public class ASTDumper {
     writeNode("ContractDeclaration") {
       self.dump(contractDeclaration.contractToken)
       self.dump(contractDeclaration.identifier)
-      if !contractDeclaration.conformances.isEmpty {
-        self.writeNode("Conforms to") {
-          for traitIdentifier in contractDeclaration.conformances {
-            self.dump(traitIdentifier)
-          }
-        }
-      }
       if !contractDeclaration.states.isEmpty {
         self.dump(contractDeclaration.states)
       }

Sources/AST/Declaration/ContractDeclaration.swift

@@ -13,7 +13,6 @@ public struct ContractDeclaration: ASTNode {
 
   public var contractToken: Token
   public var identifier: Identifier
-  public var conformances: [Identifier]
   public var states: [TypeState]
   public var members: [ContractMember]
 
@@ -47,19 +46,17 @@ public struct ContractDeclaration: ASTNode {
     return EnumDeclaration(enumToken: enumToken, identifier: stateEnumIdentifier, type: intType, cases: cases)
   }
 
-  public init(contractToken: Token, identifier: Identifier, conformances: [Identifier], states: [TypeState], members: [ContractMember]) {
+  public init(contractToken: Token, identifier: Identifier, states: [TypeState], members: [ContractMember]) {
     self.identifier = identifier
     self.members = members
-    self.conformances = conformances
     self.states = states
     self.contractToken = contractToken
   }
 
   // MARK: - ASTNode
   public var description: String {
-    let conformsText = conformances.map ({ $0.description }).joined(separator: ", ")
-    let stateText = states.map({ $0.description }).joined(separator: ", ")
-    let headText = "contract \(identifier): \(conformsText) \(stateText)"
+    let stateText = states.map({ $0.description }).joined(separator: " ")
+    let headText = "contract \(identifier) \(stateText)"
     let memberText = members.map({ $0.description }).joined(separator: "\n")
     return "\(headText) {\(memberText)}"
   }

Sources/Parser/Parser+Components.swift

@@ -21,18 +21,17 @@ extension Parser {
 
   func parseIdentifierGroup() throws -> (identifiers: [Identifier], closeBracketToken: Token) {
     try consume(.punctuation(.openBracket), or: .badDeclaration(at: latestSource))
-    guard let closingIndex = indexOfFirstAtCurrentDepth([.punctuation(.closeBracket)]) else {
-      throw raise(.expectedCloseParen(at: latestSource))
-    }
-    let identifiers = try parseIdentifierList(upTo: closingIndex)
+    let identifiers = try parseIdentifierList()
     let closeBracketToken = try consume(.punctuation(.closeBracket), or: .expectedCloseParen(at: latestSource))
 
     return (identifiers, closeBracketToken)
   }
 
-  func parseIdentifierList(upTo closingIndex: Int) throws -> [Identifier] {
+  func parseIdentifierList() throws -> [Identifier] {
     var identifiers = [Identifier]()
-
+    guard let closingIndex = indexOfFirstAtCurrentDepth([.punctuation(.closeBracket)]) else {
+      return []
+    }
     while currentIndex < closingIndex {
       identifiers.append(try parseIdentifier())
       if currentIndex < closingIndex {
@@ -158,15 +157,6 @@ extension Parser {
     return (callerCapabilities, closeBracketToken)
   }
 
-  // MARK: Conformances
-  func parseConformances() throws -> [Identifier] {
-    try consume(.punctuation(.colon), or: .expectedConformance(at: latestSource))
-    guard let endOfConformances = indexOfFirstAtCurrentDepth([.punctuation(.openBracket), .newline, .punctuation(.openBrace)]) else {
-      throw raise(.expectedConformance(at: latestSource))
-    }
-    return try parseIdentifierList(upTo: endOfConformances)
-  }
-
   // MARK: Type State
   func parseTypeStateGroup() throws -> [TypeState] {
     let (identifiers, _) = try parseIdentifierGroup()

Sources/Parser/Parser+Declaration.swift

@@ -47,19 +47,17 @@ extension Parser {
   func parseContractDeclaration() throws -> ContractDeclaration {
     let contractToken = try consume(.contract, or: .badTopLevelDeclaration(at: latestSource))
     let identifier = try parseIdentifier()
-    var states: [TypeState] = []
-    var conformances: [Identifier] = []
-    if currentToken?.kind == .punctuation(.colon) {
-      conformances = try parseConformances()
-    }
+    let states: [TypeState]
     if currentToken?.kind == .punctuation(.openBracket) {
       states = try parseTypeStateGroup()
+    } else {
+      states = []
     }
     try consume(.punctuation(.openBrace), or: .leftBraceExpected(in: "contract declaration", at: latestSource))
     let members = try parseContractMembers(enclosingType: identifier.name)
     try consume(.punctuation(.closeBrace), or: .rightBraceExpected(in: "contract declaration", at: latestSource))
 
-    return ContractDeclaration(contractToken: contractToken, identifier: identifier, conformances: conformances, states: states, members: members)
+    return ContractDeclaration(contractToken: contractToken, identifier: identifier, states: states, members: members)
   }
 
   func parseStructDeclaration() throws -> StructDeclaration {

Sources/Parser/Parser.swift

@@ -55,7 +55,6 @@ public class Parser {
         switch tld {
         case .contractDeclaration(let contract):
           environment.addContract(contract)
-          // TODO: Add conformances here 
           if contract.isStateful {
             environment.addEnum(contract.stateEnum)
           }

Sources/Parser/ParserError.swift

@@ -54,9 +54,6 @@ extension Diagnostic {
   static func expectedBehaviourSeparator(at sourceLocation: SourceLocation) -> Diagnostic {
     return Diagnostic(severity: .error, sourceLocation: sourceLocation, message: "Expected behaviour separator")
   }
-  static func expectedConformance(at sourceLocation: SourceLocation) -> Diagnostic {
-    return Diagnostic(severity: .error, sourceLocation: sourceLocation, message: "Expected conformance")
-  }
 
   // MARK: Statement
   static func expectedStatement(at sourceLocation: SourceLocation) -> Diagnostic {

docs/grammar.abnf

@@ -9,7 +9,7 @@ topLevelDeclaration = contractDeclaration
                         / enumDeclaration;
 
 ; CONTRACTS
-contractDeclaration = %s"contract" SP identifier [":" WSP identifierList ] SP [identifierGroup] SP "{" *(WSP variableDeclaration CRLF) "}";
+contractDeclaration = %s"contract" SP identifier SP [identifierGroup] SP "{" *(WSP variableDeclaration CRLF) "}";
 
 ; VARIABLES
 variableDeclaration = [*(modifier SP)] SP (%s"var" / %s"let") SP identifier typeAnnotation [WSP "=" WSP expression];
@@ -55,11 +55,10 @@ contractBehaviourMember = functionDeclaration
                             / fallbackDeclaration;
 
 ; ACCESS GROUPS
-stateGroup              = "@" identifierGroup;
+stateGroup               = "@" identifierGroup;
 callerCapabilityBinding = identifier WSP "<-";
 callerCapabilityGroup   = identifierGroup;
-identifierGroup         = "(" identifierList ")";
-identifierList          = identifier *("," WSP identifier)
+identifierGroup           = "(" identifier *("," WSP identifier) ")";
 
 ; FUNCTIONS + INITIALIZER + FALLBACK
 functionDeclaration    = functionHead SP identifier parameterList [returnType] codeBlock;