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by blenderob 98 days ago
> Am I reading this right that people can (and do??) use images as a complete replacement for source code files?

Images are not replacements of source code files. Images are used in addition to source code files. Source code is checked in. Images are created and shipped. The image lets you debug things live if you've got to. You can introspect, live debug, live patch and do all the shenanigans. But if you're making fixes, you'd make the changes in source code, check it in, build a new image and ship that.
1 comments
em-bee 97 days ago
in smalltalk you make the changes in the image while it is running. the modern process is that you then export the changes into a version control system. originally you only had the image itself. apparently squeak has objects inside that go back to 1977: https://lists.squeakfoundation.org/archives/list/squeak-dev@...
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igouy 97 days ago
Does "originally" mean before release from the offices and corridors of Xerox Palo Alto Research Center.

Perhaps further back: before change sets, before fileOut, before sources and change log ? There's a lot of history.

I wonder if the Digitalk Smalltalk implementation "has objects inside that go back to 1977".

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em-bee 96 days ago
with originally i meant before the use of version control systems became common and expected. i don't know the actual history here, but i just found this thread that looks promising to contain some interesting details: https://news.ycombinator.com/item?id=15206339 (it is also discussing lisp which bring this subthread back in line with the original topic :-)
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igouy 93 days ago
In that case

https://news.ycombinator.com/item?id=47354288

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em-bee 93 days ago
that's very interesting, thank you, i should have realized that even early on there had to be a way to share code between images. (and i don't know why i missed that comment before responding myself)

but, doesn't building a new system image involve taking an old/existing image, adding/merging all the changes, and then release new image and sources file from that?

in other words, the image is not recreated from scratch every time and it is more than just a cache.

what is described there is the process of source management in the absence of a proper revision control system. obviously when multiple people work on the same project, somewhere the changes need to be tracked and merged.

but that doesn't change the fact that the changes first happen in an image, and that you could save that image and write out a new sources file.

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igouy 57 days ago
Sorry I failed to notice your reply.

> image is not recreated from scratch every time and it is more than just a cache

Yes, some vm & image & sources & changes can be taken as the base implementation for development purposes -- a persistent cache.

The state of whatever IDE tools were in use will be saved -- is that what makes you say "more than just a cache"? If I sleep a windows desktop is that more than just a cache?

> changes first happen in an image

What if I write a plain-text source code file using Notepad, and use Smalltalk file handling and byte code compilation and command-line argument handling (packaged in the image) to write the result of a computation to stdout (and quit the image without saving)?

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