Alecs P. Hacker
@bisimulation.bsky.social
liquid type in liquid type connoisseur
alecsferra.github.io
alecsferra.github.io
Pinned
Alecs P. Hacker
@bisimulation.bsky.social
· Sep 25
The computational interpretation is the only thing that matters
Independent type theory
November 12, 2025 at 8:58 PM
Independent type theory
Calculus of explicit substitution where you have the notion of 700 different kind of substitutions
November 12, 2025 at 1:10 PM
Calculus of explicit substitution where you have the notion of 700 different kind of substitutions
Cit. Some anarchist
"make invalid states unrepresentable" pales in comparison to my strategy of assuming the state will always be valid
November 12, 2025 at 6:03 AM
Cit. Some anarchist
Why is mechanizing models so hard?? And why is 4 now? Two mins ago it was 22
November 12, 2025 at 3:00 AM
Why is mechanizing models so hard?? And why is 4 now? Two mins ago it was 22
The rust vs filc war on twitter is reaching new levels of cringed
November 11, 2025 at 10:58 PM
The rust vs filc war on twitter is reaching new levels of cringed
Name resolution broke again award
November 11, 2025 at 7:30 PM
Name resolution broke again award
Ind-Rec in Liquid Haskell before GTA 6
data Code where
...
CPi :: Code -> (ElCode -> Code) -> Code
...
{-@ stratified ElCode @-}
data ElCode where
...
{-@ EPi :: d:Code -> m:(Ix ElCode d -> Code)
-> (z:Ix ElCode d -> Ix ElCode (m z))
-> Ix ElCode (CPi d m) @-}
...
data Code where
...
CPi :: Code -> (ElCode -> Code) -> Code
...
{-@ stratified ElCode @-}
data ElCode where
...
{-@ EPi :: d:Code -> m:(Ix ElCode d -> Code)
-> (z:Ix ElCode d -> Ix ElCode (m z))
-> Ix ElCode (CPi d m) @-}
...
November 11, 2025 at 7:04 PM
Ind-Rec in Liquid Haskell before GTA 6
data Code where
...
CPi :: Code -> (ElCode -> Code) -> Code
...
{-@ stratified ElCode @-}
data ElCode where
...
{-@ EPi :: d:Code -> m:(Ix ElCode d -> Code)
-> (z:Ix ElCode d -> Ix ElCode (m z))
-> Ix ElCode (CPi d m) @-}
...
data Code where
...
CPi :: Code -> (ElCode -> Code) -> Code
...
{-@ stratified ElCode @-}
data ElCode where
...
{-@ EPi :: d:Code -> m:(Ix ElCode d -> Code)
-> (z:Ix ElCode d -> Ix ElCode (m z))
-> Ix ElCode (CPi d m) @-}
...
Reposted by Alecs P. Hacker
> default value
> look inside
>
> look inside
>
November 11, 2025 at 5:58 PM
> default value
> look inside
>
> look inside
>
TW: French language
November 11, 2025 at 5:43 PM
TW: French language
Clearly the terms shallow and deep embedding got swapped around
November 11, 2025 at 1:38 PM
Clearly the terms shallow and deep embedding got swapped around
Github copilot agent attempt 2
November 7, 2025 at 2:47 PM
Github copilot agent attempt 2
0.5 multiplicity
November 7, 2025 at 9:27 AM
0.5 multiplicity
Reposted by Alecs P. Hacker
haskell is just so nice to write
November 6, 2025 at 6:02 PM
haskell is just so nice to write
Reposted by Alecs P. Hacker
call me an arrow with choice the way i ||| when i see you 😳
November 6, 2025 at 5:28 PM
call me an arrow with choice the way i ||| when i see you 😳
Computer scientist apparently love to pove that substitution respect everything else every single time
November 6, 2025 at 1:02 PM
Computer scientist apparently love to pove that substitution respect everything else every single time
Implementations of C have had to become increasingly complex to maintain the illusion that C maps easily to the underlying hardware and gives fast code
queue.acm.org/detail.cfm?i...
queue.acm.org/detail.cfm?i...
C Is Not a Low-level Language - ACM Queue
queue.acm.org
November 6, 2025 at 8:35 AM
Implementations of C have had to become increasingly complex to maintain the illusion that C maps easily to the underlying hardware and gives fast code
queue.acm.org/detail.cfm?i...
queue.acm.org/detail.cfm?i...
"-fno-plt" disables programming language theory in the compiler
What the heck is a trampoline, anyway?
The blog post is now live! Come one, come all - enjoy this deep dive that commemorates going down the compiler rabbit hole (twice! in the Paris airport!)
savannah.dev/posts/what-t...
The blog post is now live! Come one, come all - enjoy this deep dive that commemorates going down the compiler rabbit hole (twice! in the Paris airport!)
savannah.dev/posts/what-t...
November 5, 2025 at 8:29 AM
"-fno-plt" disables programming language theory in the compiler
Code code code code code code code code code
November 4, 2025 at 8:48 PM
Code code code code code code code code code
Just be more predicative bro
November 4, 2025 at 5:08 PM
Just be more predicative bro
Why should I care about the type of type?
November 4, 2025 at 4:40 PM
Why should I care about the type of type?
Experience report, I was using the default model offered by gh in a code space, the task was pretty easy:
- Add a new type declaration in the standard library
- Update the documentation and error messages to use the new type instead of the one we were using before
And it was able to fail miserably
- Add a new type declaration in the standard library
- Update the documentation and error messages to use the new type instead of the one we were using before
And it was able to fail miserably
Im trying out vscode online and agentic coding
November 3, 2025 at 3:51 PM
Experience report, I was using the default model offered by gh in a code space, the task was pretty easy:
- Add a new type declaration in the standard library
- Update the documentation and error messages to use the new type instead of the one we were using before
And it was able to fail miserably
- Add a new type declaration in the standard library
- Update the documentation and error messages to use the new type instead of the one we were using before
And it was able to fail miserably
What a waste of time, I'll do it on my own
Im trying out vscode online and agentic coding
November 3, 2025 at 1:12 PM
What a waste of time, I'll do it on my own
Im trying out vscode online and agentic coding
November 3, 2025 at 12:37 PM
Im trying out vscode online and agentic coding
Using github from inside emacs!
November 3, 2025 at 11:52 AM
Using github from inside emacs!