Dear R Community,

One thing that always bugged me about R is the abundance of multi-level nested 
statements, like:

cumsum(ifelse(c(1,diff(v)),1,0))

because:

a) you have to read them inside out as opposed to left-to-right
b) in the console you always have to go back and type the parenthesis if you 
want to nest your statement
I kind of like the UNIX pipe operator as a very good abstraction of a data flow 
and would fancy to have something like this in R:
v %|% diff %|% c(1, value) %|% ifelse(value, 1, 0) %|% cumsum 
so I went ahead and wrote it:

"%|%" <- function(x,y) 
{ 
# Operator similar to the UNIX pipe operator. Allows to set up a chain of 
functions 
# where the result of one function will be the input of the next.
# 
# x: any R statement. will be passed to y as a parameter
# y: either a) the name of a single-parameter function or b) a function call, 
where "value"
# will be replaced with the x parameter  
#       
# Example use 1: > c(1,2,3) %|% sum
#   results in [1] 6
# Example use 2: > c(1,2,3) %|% rep(value, 10)
#   results in [1] 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3  
        
        thecall<-match.call() #get call
        
        #for functions with one parameter call it with x. Example: "c(1,2,3) 
%|% sum" -> 6
        if(is.name(thecall$y) || is.function(thecall$y)) return (y(x))          
        
        
        #instead of value use x
        value <- eval(thecall$x)
        
        return(eval(thecall$y)) #evaluate
}

would be happy to receive some feedback on

1. Would you find this useful?
2. Is there any bugs/features that you'd like to mention?
3. Should I go ahead and make an R package on that?

Cheers,
Robert
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