[R] R and Scheme

[Peter Dalgaard]

Johannes Huesing wrote:
> Stavros Macrakis <macrakis at alum.mit.edu> [Wed, Dec 10, 2008 at 04:59:25AM CET]:
>> So I conclude that what is really meant by "R semantics are based on Scheme
>> semantics" is "R has functions as first-class citizens and a correct
>> implementation of lexical scope, including upwards funarg".
>>
> 
> One other thing reminiscient of Lisp is the infix notation (as in "+"(1, 3)), 
> which the authors have sprinkled with enough syntactic sugar that the users
> needn't be bothered with. To the benefit of ubiquity, I'd think.
> 

That's prefix notation, infix is "1+3" (and postfix is "1,3,+" as in old 
HP calculators). But you're right that R has Lisp-like parse trees with 
a thin layer of syntactic sugar:

Lisp writes function calls as (f x y) for f(x,y) and (+ 1 3) for 1+3. In 
R we have

 > e <- quote(f(x,y))
 > e[[1]];e[[2]]; e[[3]]
f
x
y
 > e <- quote(1+3)
 > e[[1]];e[[2]]; e[[3]]
`+`
[1] 1
[1] 3

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