     let indices = try parseTypeIndices()
     let whereTok = try consume(.whereKeyword)
     let leftBrace = try consume(.leftBrace)
-    let constrList = parseConstructorList()
+    let constrList = try parseConstructorList()
     let rightBrace = try consume(.rightBrace)
     let semi = try consume(.semicolon)
     return DataDeclSyntax(


  func parseBasicExprListArrowExpr() throws
    -> BasicExprListArrowExprSyntax {
    let exprList = try parseBasicExprList()
    let arrow = try consume(.arrow)
    let outputExpr = try parseExpr()
    return BasicExprListArrowExprSyntax(
      exprList: exprList,
      arrowToken: arrow,
      outputExpr: outputExpr
    )
  }

  func parseLambdaExpr() throws -> LambdaExprSyntax {

    let paramList = try parseTypedParameterList()
    let whereKw = try consume(.whereKeyword)
    let leftBrace = try consume(.leftBrace)
    let declList = try parseDeclList()
    let rightBrace = try consume(.rightBrace)
    let semi = try consume(.semicolon)
    return ModuleDeclSyntax(
