Ashok P. Nadkarni 2017-09-10
Many programming tasks are very simply expressed and implemented through recursive algorithms, traversing a tree data structure being just one example. The primary reason recursion simplifies implementation is that the state of the computation is implicitly maintained, freeing the programmer from the burden of explicitly tracking the computational state of the program. For example, in a recursive tree walking implementation, the "current location" in the tree is implicitly tracked.
However, there are situations where a recursive model does not fit the needs of an application. For example, the application may want to traverse a tree in iterative fashion, retrieving one node at a time, operating on it and then potentially doing some unrelated computation before retrieving the next node at some unknown point in the future.
Here is where coroutines can bridge the impendance mismatch, presenting an iterative interface to a naturally recursive algorithm more ...
Ashok P. Nadkarni 2017-08-04
A previous blog post described the representation command and its use for introspecting Tcl's internal structures for storing data. I promised a follow-up post that talked about Tcl's compiled byte code and the disassemble command for inspecting it. Well, only two years later, here is that post as promised more ...
Ashok P. Nadkarni 2016-01-23
In a prior post I had illustrated the use of the Tcl promise package for asynchronous computing with some examples. There we had ignored the possibility of errors and exceptions and how they are handled in promise-based code. In this post, we build on the examples in that post to illustrate how promises greatly simplify handling of errors in async code more