#functor — Public Fediverse posts

C++OnSea 2025 SESSION ANNOUNCEMENT: Safe and Readable Code: Monadic Operations in C++23 by @asperamanca

https://cpponsea.uk/2025/session/safe-and-readable-code-monadic-operations-in-cpp23

Register now at https://cpponsea.uk/tickets/

#expected #functor #monad #optional #ranges

Recall that a #colimit of a #diagram in a #category C, that is, of a #functor F:J→C, is #given by a #universal [[#cocone]] for F. A [[#co #cone]] for F is a #natural #transformation from F to a #constant diagram,

Δ(c)=(J→1→cC),

so that a cocone for F is an #object of a #comma category,

F↓Δ,

where Δ:C1→CJ is the #diagonal functor #obtained by #pulling #back #along the #unique functor J→1. A universal cocone is #simply an #initial object of F↓Δ.

Recall that a #colimit of a #diagram in a #category C, that is, of a #functor F:J→C, is #given by a #universal [[#cocone]] for F. A [[#co #cone]] for F is a #natural #transformation from F to a #constant diagram,

Δ(c)=(J→1→cC),

so that a cocone for F is an #object of a #comma category,

F↓Δ,

where Δ:C1→CJ is the #diagonal functor #obtained by #pulling #back #along the #unique functor J→1. A universal cocone is #simply an #initial object of F↓Δ.