The term is "dynamic scope": https://en.wikipedia.org/wiki/Scope_(computer_science)#Lexic...
It isn't a very common language feature, but you could take a look at React's `Context` or Common Lisp's `defparameter`.
It isn't a very common language feature, but you could take a look at React's `Context` or Common Lisp's `defparameter`.
I was imagining more along the lines of (on-the-spot pseudo-code)
using [x := foo(...)]
{
bar();
output();
}
func bar()
{
x = x + 1
}
Anyway, cheers, always fun to ponder these things.
The killer feature is that you can shadow a dynamic variable, changing its value for the duration of a dynamic scope, in the same way that an inner `catch` handler overrides an outer one.
For example, you could have a dynamic variable which tells the `print` function where to send its text output. The variable's value would probably default to stdout. By temporarily assigning a string-stream to that variable, you could collect an arbitrary function's text output into a string instead. Regardless of where the text is going, any function which produces text could still use the convenient global `print` function.
Of course, no compile-time checking there, so the combination sounds indeed quite useful.
https://github.com/serilog/serilog/wiki/Enrichment#the-logco...