[Rd] Improving string concatenation

[Hervé Pagès]

Hi Joshua,

On 06/17/2015 11:24 AM, Joshua Bradley wrote:
>> How would this new '+' deal with factors, as paste does or as the current
> '+'
>> does?  Would number+string and string+number cause errors (as in current
>> '+' in R and python) or coerce both to strings (as in current R:paste and
> in perl's '+').
>
>
> I had posted this sample code previously to demonstrate how string
> concatenation could be implemented
>
> "+" = function(x,y) {
>      if(is.character(x) & is.character(y)) {
>          return(paste0(x , y))
>      } else {
>          .Primitive("+")(x,y)
>      }}
>
>
> so it would only happen if both objects were characters,

Problem with this is that it's inconsistent with other binary operators
that will first coerce the non-character operand to character if the
other operand is a character.

H.

> otherwise you
> should expect the same behavior as before with all other classes. This
> would be backwards compatible as well since string+string was never
> supported before and therefore no one would have previously working code
> that could break.
>
> Josh Bradley
>
> 	[[alternative HTML version deleted]]
>
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>

-- 
Hervé Pagès

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