“varid”，“varsym”和“varid”之间的语义差异是什么？在Haskell报告中？ [英] What is the semantic difference between "varid", "varsym" in Haskell Report?

问题描述

我正在阅读2010年的Haskell报告，并且有关于2.4节中的元逻辑表示的一些问题这里：

1. 在varid和varsym的助记符中，var是指变量吗？


2. 我的理解是，varid是变量和函数的标识符，而varsym也是标识符，但是对于运算符。这种理解是否正确？


3. 如果1和2是正确的，是否意味着operator也是一种变量？ （我很困惑，因为这可能是不对的。）

欣赏任何建议。解决方案

据我所知，报告定义了使用前缀的符号和使用中缀的符号之间的区别，例如：

b
$ b

  fxy  -  f用于前缀
 
a / b  -  /用于中缀
  
 
 $ b 
这只是一个句法上的便利，因为所有的前缀符号都可以用反斜杠加中缀，而且所有的中缀符号都可以用前缀（） s：
  x`f` y  - 中缀
 
（/）ab  - 前缀
（a /）b  - 运算符部分
（/ b）a  - 运算符部分
  
小问题： 
 
 
 
 
 
无法找出 id 和 sym 部分的任何有意义的助记符。 ：（
 
）
 
 
运算符处于Haskell语法领域，而不是其语义，它们仅用于为编写某些表达式提供更方便的语法。就我所知，如果它们从Haskell中被移除，唯一的损失将是方便的语法 - 也就是说，除了方便的语法之外，没有什么需要运算符的，并且可以用非运算符符号替换运算符的每一次使用。它们与变量完全相同 - 它们是变量 - 但需要不同的语法来使用它们。
 是的，我会同意运算符是变量，但绑定到符号符号的值不会是变量。  
 
 
I am reading the Haskell report 2010 and has some questions with regarding to the meta-logical representation in section 2.4Here:

In the mnemonics of "varid" and "varsym", does "var" mean variable?
My understanding are that "varid" are identifiers for variables and functions, while "varsym" are identifiers also, but for operators. Is this understanding correct?
If 1 and 2 are correct, does it mean operator is also  a kind of variable? (I am very confused because this is likely not right.)
Appreciate any advice.
解决方案
As far as I can tell, the report is defining the difference between symbols that are used prefix, and those that are used infix, for example:
f x y -- f is used prefix

a / b -- / is used infix
This is just a syntactic convenience, as all prefix symbols can be used infix with backticks, and all infix symbols can be used prefix with ()s:
x `f` y -- infix

(/) a b -- prefix
(a /) b -- operator section
(/ b) a -- operator section
Sub-questions:

yes, but I can't figure out any meaningful mnemonic for the id and sym parts. :(
operators are in the realm of Haskell syntax, not its semantics.  They're only used to provide a more convenient syntax for writing some expressions.  As far as I know, if they were removed from Haskell, the only loss would be convenient syntax -- i.e. there's nothing that you need operators for, other than convenient syntax, and you can replace every single use of operators with non-operator symbols.  They are completely identical to variables -- they are variables -- but require different syntax for their use.
yes, I would agree that operator symbols are variables.  However, the values bound to oerators symbols would not be variables.


                        
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