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Ask HN: How do you learn new libraries without much documentation?

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Re: Ask HN: How do you learn new libraries without much documentation?

#21

Post by sillysaurusx »

petepete wrote: post #20
sillysaurusx wrote: post #11

1. learn a good editor. 2. write a script to concatenate all the code files in a folder, separated by filenames. 3. pipe that result to your editor. 4. use your editor's "find" functionality. By reading the entire source code in a single file, you have global knowledge of the entire codebase. All the information is available to you. I suggest you try it before dismissing the idea, as I once did. https://github.com/sh…

I'd recommend just learning ag (or ripgrep), they make searching across projects dead easy and support limiting to specific filetypes. Reading all the code might be a decent approach for small libraries but sometimes it's excessive.

This recommendation often leads to confusion. Every time you search for something using ag or rg, you're losing all the context around the code. And yeah, -C 10 is a thing, but it's a shadow of having the actual code in an actual editor.

It's remarkable how offensive this idea is to people. It's not like I came up with the idea this morning. I've been reading hundred-thousand line codebases for many, many years this way. It's how I studied and understood the original bitcoin codebase.

But, you know, if you really want to be stuck in the loop of "ok, this file calls Foo, let me switch to terminal and search for Foo... Ok, now I'll open that file and read it.. Oh it calls Bar, I'll search for bar..." then feel free.

And yeah, an IDE is the antidote. If it's a JS project, use `webstorm .`. For python, use `charm .` Unfortunately `clion .` doesn't seem to work for C++ codebases -- you have to "import" the code first, which is highly annoying and generates extra CMakeList.txt flies. VSCode might be fine and automatic and perfect go-to-definition functionality even for template metaprogramming; I don't know.

But I do know that the technique I've described above will work 100% of the time.

Re: Ask HN: How do you learn new libraries without much documentation?

#22

Post by quanticle »

sillysaurusx wrote: post #21
petepete wrote: post #20

Earlier quoted context omitted.

I'd recommend just learning ag (or ripgrep), they make searching across projects dead easy and support limiting to specific filetypes. Reading all the code might be a decent approach for small libraries but sometimes it's excessive.

This recommendation often leads to confusion. Every time you search for something using ag or rg, you're losing all the context around the code. And yeah, -C 10 is a thing, but it's a shadow of having the actual code in an actual editor. It's remarkable how offensive this idea is to people. It's not like I came up with the idea this morning. I've been reading hundred-thousand line codebases for many, many years this…

That's why you use a plugin that integrates ag or ripgrep into your editor so that you can see the context in your editor as you search.

Re: Ask HN: How do you learn new libraries without much documentation?

#23

Post by vbsteven »

sillysaurusx wrote: post #17
izacus wrote: post #14

Earlier quoted context omitted.

This sounds like trying to create a poor man's IDE with go to definition / find usages functionality. Is there an IntelliJ product for JS yet?

I regularly read and understand 50,000+ line codebases with this technique. Again, I suggest trying it before dismissing the idea. A good IDE is nice, when they work, but this fallback has worked 100% of the time. CLion is for C++. PyCharm is for Python. Webstorm is for JS. But Vim is for everything. To put it differently: how often do you use ripgrep on a large codebase? If the answer is "often," then every time you…

No argument against the one code file thing because I think it’s a great idea. But a quick comment on the JetBrains suite:

With the right plugins Intellij Ultimate is also for everything (just like Vim uses language plugins) and then you get all the benefits of the modern IDE. Intellisense, search, replace, refactor, find usage, type inference, etc

I’m not saying vim cannot do this but Intellij is now my preference for everything and I don’t feel the need for merging everything in one file for analysis because I can jump around to definitions/usages easily.

Re: Ask HN: How do you learn new libraries without much documentation?

#24

Post by quanticle »

thinkingemote wrote: post #5

Look at the library's tests. It's quicker and better for learning functionality than "just read the source code". If it's proprietary and closed and obfuscated then you need to familiarise yourself with reverse engineering toolsets.

The corollary to this is, "If there aren't tests, start by writing some unit tests on your own that exercise the library's functionality."

Re: Ask HN: How do you learn new libraries without much documentation?

#25

Post by [deleted] »

sillysaurusx wrote: post #17
izacus wrote: post #14

Earlier quoted context omitted.

This sounds like trying to create a poor man's IDE with go to definition / find usages functionality. Is there an IntelliJ product for JS yet?

I regularly read and understand 50,000+ line codebases with this technique. Again, I suggest trying it before dismissing the idea. A good IDE is nice, when they work, but this fallback has worked 100% of the time. CLion is for C++. PyCharm is for Python. Webstorm is for JS. But Vim is for everything. To put it differently: how often do you use ripgrep on a large codebase? If the answer is "often," then every time you…

[deleted]

Re: Ask HN: How do you learn new libraries without much documentation?

#27

Post by xadoc »

If the code has tests, I would start by looking at those tests.

If it has no tests, then I would slowly try to build tests to document the functionality that I need. In your case being Angular that might be having simple html pages with the smallest module that you need.

How to find things? If you're on Windows try AstroGrep http://astrogrep.sourceforge.net/ to quickly search and jump around in the code or in any system I use VS Code for a similar functionality. Also learn to use command line find/grep.

The book "Working Effectively with Legacy Code" also helped me be more comfortable navigating and changing large code bases, in a long term view I recommend this book to every developer https://www.amazon.co.uk/Working-Effectively-Legacy-Michael-...

Lastly, I would raise this because the company might not be aware they are buying a low quality framework that maybe ticks all the boxes in the contract but is in effect impossible to use by their current developers (you), it might be there's other people with more experience in said niche that might be able to help. In the private community maybe some people would be able to accept a short contract to help train you.

Re: Ask HN: How do you learn new libraries without much documentation?

#28

Post by sillysaurusx »

quanticle wrote: post #22
sillysaurusx wrote: post #21

Earlier quoted context omitted.

This recommendation often leads to confusion. Every time you search for something using ag or rg, you're losing all the context around the code. And yeah, -C 10 is a thing, but it's a shadow of having the actual code in an actual editor. It's remarkable how offensive this idea is to people. It's not like I came up with the idea this morning. I've been reading hundred-thousand line codebases for many, many years this…

That's why you use a plugin that integrates ag or ripgrep into your editor so that you can see the context in your editor as you search.

Sure, that's fine. Personally, I hate dealing with vim plugin nonsense, and especially with getting vim environments working on a remote server inside tmux. But whatever works.

Re: Ask HN: How do you learn new libraries without much documentation?

#29

Post by lawik »

When I've been using open source libraries without significant docs I've mostly benefitted from actually reading the code. Assuming you have the source. This can be incredibly varying in complexity. I've found a large Elixir codebase, as a functional paradigm easier to grasp compared to a single library in heavy OOP style in Python. Python not enforcing much structure and this particular library doing a lot of inheritance which complicates the state and modelling in my head a lot. So it varies a lot per code base and experience. But if you have the code, that's what I'd use.

Re: Ask HN: How do you learn new libraries without much documentation?

#30

Post by sillysaurusx »

vbsteven wrote: post #23
sillysaurusx wrote: post #17

Earlier quoted context omitted.

I regularly read and understand 50,000+ line codebases with this technique. Again, I suggest trying it before dismissing the idea. A good IDE is nice, when they work, but this fallback has worked 100% of the time. CLion is for C++. PyCharm is for Python. Webstorm is for JS. But Vim is for everything. To put it differently: how often do you use ripgrep on a large codebase? If the answer is "often," then every time you…

No argument against the one code file thing because I think it’s a great idea. But a quick comment on the JetBrains suite: With the right plugins Intellij Ultimate is also for everything (just like Vim uses language plugins) and then you get all the benefits of the modern IDE. Intellisense, search, replace, refactor, find usage, type inference, etc I’m not saying vim cannot do this but Intellij is now my preference f…

Yeah, that's valid. `idea .` seemed to work occasionally back when I tried. But what I ran into was, you often want to install specific plugins for JS, and specific plugins for Python, etc. On my laptop, the result was that IDEA started taking like ... 4 minutes to fully load a codebase. So I just gave up.

But IntelliJ is wonderful in general. Maybe others will have more luck.

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