Analysis of information sources in references of the Wikipedia article "协程" in Chinese language version.
In SIMULA, a coroutine is represented by an object of some class, co-operating by means of resume instructions with objects of the same or another class, which are named by means of reference variables. ……
Thus a main program may establish a coroutine relationship with an object that it has generated, using the call/detach mechanism instead of the more symmetric resume/resume mechanism. In this case, the generated object remains subordinate to the main program, and for this reason is sometimes known as a Semicoroutine. ……
Let X and Y be objects, generated by a "master program" M. Assume that M issues a call (X), thereby invoking an "active phase" of X, terminated by a detach operation in X; and then issues a call (Y), and so forth. In this way M may act as a "supervisor" sequencing a pattern of active phases of X, Y, and other objects. Each object is a "slave", which responds with an active phase each time it is called for, whereas M has the responsibility to define the large scale pattern of the entire computation.
Alternatively the decision making may be "decentralised", allowing an object itself to determine its dynamic successor by a resume operation. The operation resume (Y), executed by X, combines an exit out of X (by detach) and a subsequent call (Y), thereby bypassing M. Obligation to return to M is transferred to Y.
6. Symmetry is a complexity reducing concept (co-routines include sub-routines); seek it everywhere
Pth is very portable because it has only one part which perhaps has to be ported to new platforms (the machine context initialization). But it is written in a way which works on mostly all Unix platforms which support makecontext(2) or at least sigstack(2) or sigaltstack(2) [see pth_mctx.c for details].
All of this makes generator functions quite similar to coroutines; they yield multiple times, they have more than one entry point and their execution can be suspended. The only difference is that a generator function cannot control where should the execution continue after it yields; the control is always transferred to the generator's caller.
Support for generator-based coroutines is deprecated and is removed in Python 3.11.
Theswitchstatement is a multi-way decision that tests whether an expression matches one of a number of constant integer values, and branches accordingly. ……
Each case is labeled by one or more integer-valued constants or constant expressions. If a case matches the expression value, execution starts at that case. ……
Because cases serve just as labels, after the code for one case is done, execution falls through to the next unless you take explicit action to escape. ……
Case labels and default labels are used with theswitchstatement (Par.A.9.4). ……
Labels themselves do not alter the flow of control.
If you're a C programmer then you've probably read the various introductions and tutorials on call-with-current-continuation (call/cc) and come out not much wiser about what it all really means. Here's the secret: it's setjmp/longjmp. But on no account say that to any Scheme programmers you know, it'll send them into paroxysms of rage as they tell you you don't know what you're talking about.
6. Symmetry is a complexity reducing concept (co-routines include sub-routines); seek it everywhere
Pth is very portable because it has only one part which perhaps has to be ported to new platforms (the machine context initialization). But it is written in a way which works on mostly all Unix platforms which support makecontext(2) or at least sigstack(2) or sigaltstack(2) [see pth_mctx.c for details].
Some authors use the term iterator, and others the term generator. Some make subtle distinctions between the two.
If you're a C programmer then you've probably read the various introductions and tutorials on call-with-current-continuation (call/cc) and come out not much wiser about what it all really means. Here's the secret: it's setjmp/longjmp. But on no account say that to any Scheme programmers you know, it'll send them into paroxysms of rage as they tell you you don't know what you're talking about.
6. Symmetry is a complexity reducing concept (co-routines include sub-routines); seek it everywhere
All of this makes generator functions quite similar to coroutines; they yield multiple times, they have more than one entry point and their execution can be suspended. The only difference is that a generator function cannot control where should the execution continue after it yields; the control is always transferred to the generator's caller.
Some authors use the term iterator, and others the term generator. Some make subtle distinctions between the two.
Pth is very portable because it has only one part which perhaps has to be ported to new platforms (the machine context initialization). But it is written in a way which works on mostly all Unix platforms which support makecontext(2) or at least sigstack(2) or sigaltstack(2) [see pth_mctx.c for details].
Theswitchstatement is a multi-way decision that tests whether an expression matches one of a number of constant integer values, and branches accordingly. ……
Each case is labeled by one or more integer-valued constants or constant expressions. If a case matches the expression value, execution starts at that case. ……
Because cases serve just as labels, after the code for one case is done, execution falls through to the next unless you take explicit action to escape. ……
Case labels and default labels are used with theswitchstatement (Par.A.9.4). ……
Labels themselves do not alter the flow of control.
