Difference between revisions of "Scala (Language)"
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* Also, the interpretation of "x == y" as "x.==(y)" might result in an asymmetry (loss of commutativity) which may prove particularly problematic. I'd generally consider it a good idea to have a mechanism that just is commutative, rather than having to rely on adherence to some kind of contract to ensure commutativity where that is required. | * Also, the interpretation of "x == y" as "x.==(y)" might result in an asymmetry (loss of commutativity) which may prove particularly problematic. I'd generally consider it a good idea to have a mechanism that just is commutative, rather than having to rely on adherence to some kind of contract to ensure commutativity where that is required. | ||
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| + | * The idea that language features such as comprehensions can be built on top of any type providing the appropriate methods / implementing the appropriate interfaces is quite attractive. Kind of like Python, where it's possible to pass any object implementing the methods read or readline where "normally" a file would be passed in. | ||
* Interesting hack to declare parameters of type T as "=> T" ("function returning T") to lazily evaluate parameters of that type. | * Interesting hack to declare parameters of type T as "=> T" ("function returning T") to lazily evaluate parameters of that type. | ||
Revision as of 06:05, 26 November 2011
Notes
On "An Overview of the Scala Programming Language" An Overview of the Scala Programming Language, Second Edition, by Martin Odersky et.al
- The point of Scala's pattern matching feature is not quite clear to me.
- Scala's "id: type" syntax is rather less easy to read than Java's "type id" syntax.
- The "optional semicolon" idea is very problematic, delimitation of statements should be unambiguous, and the significance of tokens (whether semicolon or newline) should be unambiguous as well. Interpreting newline as a statement terminator if a statement terminator makes sense here is an idea that has wrought havoc in R already.
- The "value oriented" interpretation of the == operator seems problematic to me. What should the Scala programmer use to test for object identity?
- Also, the interpretation of "x == y" as "x.==(y)" might result in an asymmetry (loss of commutativity) which may prove particularly problematic. I'd generally consider it a good idea to have a mechanism that just is commutative, rather than having to rely on adherence to some kind of contract to ensure commutativity where that is required.
- The idea that language features such as comprehensions can be built on top of any type providing the appropriate methods / implementing the appropriate interfaces is quite attractive. Kind of like Python, where it's possible to pass any object implementing the methods read or readline where "normally" a file would be passed in.
- Interesting hack to declare parameters of type T as "=> T" ("function returning T") to lazily evaluate parameters of that type.
- According the "op1.operator(op2) is equivalent to op1 operator op2" rule, "op1 operator" represents a unary function that takes the missing operand. Hmm... is that awkward or just something to get used to?
