String interpolation transformer inline variables to string which is argument of function '$' with #{Var} syntax.
The result of such trunsformation is iolist().
'$'("text #{Var} rest text").
%% is same as
["text ", [Var], " rest text"].
'$'("text #{Var1, Var2} rest text #{Var3}").
%% is same as
["text ", [Var1, Var2], " rest text ", [Var3]].Also it can include not only variables, but any other valid erlang expression.
'$'("text #{f(Var1, '$'(\"Var2=#{Var2}\")} rest text").
%% is same as
["text ", [f(Var1, ["Var2=",[Var2]])], " rest text"].Usage example:
-module(si).
-compile({parse_transform, string_interpolation}).
-export([example/0]).
example() ->
A = "A",
B = atom,
'$'("Here is string A=#{A} and atom B=#{atom_to_list(B)}").