I may have finally finished clirenesance.

content/posts/cli-renaissance/index.md

@@ -213,8 +213,84 @@ but its an extremely usable IDE out of the box thanks to having all of its featu
 ### Helpful error messages
 
 <!-- look at nushells error messages -->
+When the user does do something wrong, it is vital to let them know exactly what, where, and how it went wrong,
+and if at all possible, what action the user can do to fix it.
+`Operation Failed`, `Error` or `syntax error` on their own are horrible error messages.
+They tell you that something *somewhere* failed, giving almost no information the user can use to troubleshoot.
+In the worst case, they can even point you in a completely different direction than what is actually needed to fix things.
+Git is a good example of this. As much as I love git, sometimes its error messages are the  opposite of helpful.
+To borrow an example from [Julia Evans](https://jvns.ca/blog/2024/04/10/notes-on-git-error-messages/#git-checkout-asdf),
+if you run `git checkout SomeNonExistantBranch`, you get:
+`error: pathspec 'SomeNonexistantBranch` did not match any file(s) known to git`.
+This is confusing because you are trying to checkout a branch, you arent thinking about files.
 
-TODO [before](../nushell)
+Another example, I covered [before](../nushell) is the contrast between Bash and Nushell.
+Consider the following script:
+{{<highlight sh "linenos=false">}}
+$ for i in $(ls -l | tr -s " " | cut --fields=5 --delimiter=" "); do
+echo "$i / 1000" | bc
+done
+{{</highlight>}}
+
+This gets the sizes of all the files in KiB. But what if we typo the cut field?
+
+{{<highlight sh "linenos=false">}}
+$ for i in $(ls -l | tr -s " " | cut --fields=6 --delimiter=" "); do
+echo "$i / 1000" | bc
+done
+
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+(standard_in) 1: syntax error
+{{</highlight>}}
+
+Due to the syntax error coming from bc rather than bash directly,
+even the line number it gives you is misleading,
+and in order to have the slightest clue whats going on,
+you have to start print debugging.
+
+The equivalent in nushell would be:
+
+{{<highlight sh "linenos=false">}}
+> ls | get size | each {|item| $item / 1000}
+{{</highlight>}}
+
+and the equivilant error would be:
+{{<highlight sh "linenos=false">}}
+> ls | get type | each {|item| $item / 1000}
+Error: nu::shell::eval_block_with_input
+
+  × Eval block failed with pipeline input
+   ╭─[entry #5:1:1]
+ 1 │ ls | get type | each {|item| $item / 1000}
+   · ─┬
+   ·  ╰── source value
+   ╰────
+
+Error: nu::shell::type_mismatch
+
+  × Type mismatch during operation.
+   ╭─[entry #5:1:30]
+ 1 │ ls | get type | each {|item| $item / 1000}
+   ·                              ──┬── ┬ ──┬─
+   ·                                │   │   ╰── int
+   ·                                │   ╰── type mismatch for operator
+   ·                                ╰── string
+   ╰────
+
+{{</highlight>}}
+
+Though the first error isnt helpful, the second one tells us right away that `$item` is not what we expect it to be,
+hopefully pointing us to the `get type` mistake.
+Nushells error messages are miles ahead of other shells just...
+being useful, helping you find where you made an error,
+rather than just telling you theres an error *somewhere*.
 
 ### Concise and discoverable documentation
 
@@ -325,9 +401,25 @@ allowing for more people to experiment with the design and ergonomics of CLI too
 
 ## Conclusion
 
-TODO
-<!-- emphasize that the new tools are not 'better' just because they are new,
-but because they take the old tools and learn what did and did not work for them. -->
+> If I have seen further than others, it is by standing on the shoulders of giants.
+
+-- Isaac Newton, 1675
+
+Once again, Id like to state that I am not advocating for shiny new tools *because* they are shiny and new.
+Likewise, I dont think the old tools are *bad*, nor does their age alone count against them.
+However, new tools have the opportunity to learn from their predecessors and build upon them.
+In this way, the new tools are a tribute to those tools that came before;
+a recognition of their strengths, an acknowledgement of their weaknesses.
+
+Now, these new tools are not the be-all end-all of the command line interface.
+Just because this new generation of tools improve on the old ones,
+it does not mean they are themselves perfect.
+As we use these tools, we will become familiar with them,
+and we will discover their sharp edges,
+or their common usecase will change,
+or we develop a new usecase entirely.
+And when these things happen, we will develop yet another generation of tools,
+one further polished and adapted to new usecases.
 
 ## Appendix: the tools