关于scala：匹配类成员“错误：找不到：值&&”

Matching on class members “error: not found: value &&”

我正试图从Twitter Scala School开始进入Scala，但是在语法错误方面遇到了麻烦。当我通过sbt控制台从"基础继续"教程http://twitter.github.io/scala_school/basics2.html#match运行"模式匹配"代码时，编译器使我回到"错误：找不到：值&&" 。 Scala中的某些内容发生了变化，以适应编写本教程时可能有效但现在不起作用的东西吗？涉及的课程是

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class Calculator(pBrand: String, pModel: String) {
/**
* A constructor
*/
val brand: String = pBrand
val model: String = pModel
val color: String = if (brand.toUpperCase =="TI") {
"blue"
} else if (brand.toUpperCase =="HP") {
"black"
} else {
"white"
}

// An instance method
def add(m: Int, n: Int): Int = m + n
}

class ScientificCalculator(pBrand: String, pModel: String) extends Calculator(pBrand: String, pModel: String) {
def log(m: Double, base: Double) = math.log(m) / math.log(base)
}

class EvenMoreScientificCalculator(pBrand: String, pModel: String) extends ScientificCalculator(pBrand: String, pModel: String) {
def log(m: Int): Double = log(m, math.exp(1))
}

我的代表看起来像这样...

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bobk-mbp:Scala_School bobk$ sbt console
[info] Set current project to default-b805b6 (in build file:/Users/bobk/work/_workspace/Scala_School/)
[info] Starting scala interpreter...
[info]
Welcome to Scala version 2.9.2 (Java HotSpot(TM) 64-Bit Server VM, Java 1.7.0_17).
Type in expressions to have them evaluated.
Type :help for more information.
...
scala> def calcType(calc: Calculator) = calc match {
| case calc.brand =="hp" && calc.model =="20B" =>"financial"
| case calc.brand =="hp" && calc.model =="48G" =>"scientific"
| case calc.brand =="hp" && calc.model =="30B" =>"business"
| case _ =>"unknown"
| }
<console>:9: error: not found: value &&
case calc.brand =="hp" && calc.model =="20B" =>"financial"
^
<console>:10: error: not found: value &&
case calc.brand =="hp" && calc.model =="48G" =>"scientific"
^
<console>:11: error: not found: value &&
case calc.brand =="hp" && calc.model =="30B" =>"business"
^
scala>

在对类成员进行匹配时，如何在我的案例中获取AND的用例？

提前致谢。我是新来的。