Shorter shorthand for StringJoin[]?

Question

As a minimal working example:

myString="some words";
myString=myString<>"more words";

Is there a shorter way to tell Mathematica that I want to "tack on" more to the end of a string? For example "C-style":

myString<>="more words";

NB: I am aware of StringInsert[myString,"more words",-1]. I am looking specifically for an expression like <>= where I can use shorthand like <>= (or something else if that's not possible) to achieve the end result.

Thanks for your insight.

Answer 1

Even though belisarius' answer is probably closest to what you want, I find that I quite often do something like this:

SetAttributes[sj,HoldFirst];
sj[x_Symbol, y__] := (x = StringJoin[x, y])

Now we can type

myString = "some words ";
sj[myString, "more words"];
myString
(* "some words more words" *)

That is, instead of using infix notation lhs someoperator rhs, you can make shorthands that "wrap": someoperator[lhs,rhs]. I got used to it quickly. Note that we can even append more strings since we used y__:

myString = "some words ";
sj[myString, "more words ","even more words"];
myString
(* "some words more words even more words" *)

Answer 2

Define your own:

<< Notation`
Notation[DoubleLongLeftRightArrow[
  ParsedBoxWrapper[
   RowBox[List["x_", " ", "⊕", " ", "y_", " "]]], 
  ParsedBoxWrapper[
   RowBox[List[" ", 
     RowBox[List["x_", "=", RowBox[List["x_", "<>", "y_"]]]]]]]]]

x = "caca";
x⊕"test";
x
(*"cacatest"*)

Edit

Using the Notation palette you should see

Answer 3

I am not sure if this is the best method, but I found this article which describes mathematica operators without predefined definitions. I used one to associate a function with the TildeTilde symbol, made by pressing esc+~+~+esc.

SetAttributes[TildeTilde, HoldFirst]
TildeTilde[a_Symbol, b_String] := (a = a <> b)

You need to use HoldFirst attribute so that it doesn't evaluate your symbol before evaluating the expression

Now using myString $\approx$ "morewords" will work like <>=

Answer 4

This can also be done using operators.

SetAttributes[DotEqual, HoldFirst];
DotEqual[a_Symbol, b_] := a = b@a; 

oStringJoin[h_] := Function[expr, StringJoin[expr, h], HoldAll];

myString = "some words ";
myString \[DotEqual] oStringJoin@"more words";

myString

(* "some words more words"  *)

Such an approach is general in the sense that can it be used for any other modifications including those with the variables parts and applying built-in operator forms (in which case you don't need to roll your own as with oStringJoin - currently all the string operators don't have operator forms but I would anticipate this changing over time). An example of other modifications with existing operator forms

Readability would be probably improved by using @= instead of \[DotEqual] as discussed here.