Mk: A Successor to Make (1987) [pdf] • Hacker News Board

Re: Mk: A Successor to Make (1987) [pdf]

#51

Post by duped » Wed, Jul 19, 2023, 1:51 PM UTC

kdmccormick wrote: post #47

duped wrote: post #35

Earlier quoted context omitted.

More of just a graph like: V: (0001, 0002) E: ([0001, 0002], [0002, 0001]) But really I was just being sarcastic. Builds are "just" DAGs with syntactic sugar just like programs are "just" DAGs with syntactic sugar. That's one possible abstraction and one that is inherently lossy, because what "sugar" is available is the actual meat that makes one build system useful and another terrible. And one actually awful limita…

Right, I understand the graph metaphor, my objection is that programs in a turing complete language do not seem like they can exhaustively modeled as DAGs. Graphs, sure; but AFAICT DAGs fail due to the halting problem (in some abstract sense). A build system modelling itself as a DAG, on the other hand, is very consciously taking on acyclicity as a feature. I am curious what builds would need to be cyclic. Artifact A…

A syntax tree is also a DAG.

> I am curious what builds would need to be cyclic.

Compilers, interpreters, kernels, and the things that depend on them. So lots.

> Does that happen in any well-designed build?

Whether or not it's 'well designed' is irrelevant, the question is 'does it need to be possible' because even if it's rare it's still present in a lot of foundational software, notably GCC.

Re: Mk: A Successor to Make (1987) [pdf]

#52

Post by nsajko » Fri, Jul 21, 2023, 3:45 PM UTC

smorrow wrote: post #49

nsajko wrote: post #37

Earlier quoted context omitted.

Both Mk and Rc started out with Research Unix, some years before Plan 9.

I've been seeing people, never ones who were actually there, make this claim in the last five to ten years. Rc was on tenth edition Unix. I've seen no evidence that it originated on Unix. The manual calls it the Plan 9 shell.

I was going by the fact that tenth edition Unix was released on 1989, while Plan 9 was first released in 1992: https://en.wikipedia.org/wiki/Research_Unix

Pehaps this is misleading.

Re: Mk: A Successor to Make (1987) [pdf]

#53

Post by smorrow » Tue, Jul 25, 2023, 3:47 PM UTC

nsajko wrote: post #52

smorrow wrote: post #49

Earlier quoted context omitted.

I've been seeing people, never ones who were actually there, make this claim in the last five to ten years. Rc was on tenth edition Unix. I've seen no evidence that it originated on Unix. The manual calls it the Plan 9 shell.

I was going by the fact that tenth edition Unix was released on 1989, while Plan 9 was first released in 1992: https://en.wikipedia.org/wiki/Research_Unix Pehaps this is misleading.

Some clues:

The mk paper (and Unix man page) doesn't mention rc.

Plan 9 existed since the mid-80s.

This sentence in the Unix rc(1) sure makes it seem like rc was Plan 9-first:

Environment entries for variables are kludgy for UNIX compatibility.

Re: Mk: A Successor to Make (1987) [pdf]

#54

Post by smorrow » Sat, Jul 29, 2023, 8:05 AM UTC

nsajko wrote: post #52

smorrow wrote: post #49

Earlier quoted context omitted.

I've been seeing people, never ones who were actually there, make this claim in the last five to ten years. Rc was on tenth edition Unix. I've seen no evidence that it originated on Unix. The manual calls it the Plan 9 shell.

I was going by the fact that tenth edition Unix was released on 1989, while Plan 9 was first released in 1992: https://en.wikipedia.org/wiki/Research_Unix Pehaps this is misleading.

The first paragraph of https://archive.org/details/rc-shell/

So rc was made for Plan 9. The examples in that paper are definitely on tenth edition Unix, I think this would be because

A fairly complete version of Plan 9 was built in 1987 and 1988, but development was abandoned. In May of 1989 work was begun on a completely new system

from https://doc.cat-v.org/plan_9/1st_edition/designing_plan_9 (1990).