This repository is a collection of D modules written by Ali Çehreli.
The package name alid is a combination of "Ali" and "D".
It started with cached which was based on an old idea of
Ali's that rested
for more than ten years. Ali decided to revisit the idea when a piece of D
code--written by Janis, a friend and colleague--produced surprising results. The
surprises were due to side effects in a generator function similar to the map
lambda in the following code:
auto r = iota(n)
.map!((i) {
arr ~= i; // <-- A side effect (adds to an array)
return i;
})
.filter!(i => true); // <-- The side effect is repeatedEvery access to the generated "element" down the execution chain repeats the side effect, adding one more element to the array in the code above.
cached is for executing elements only once while not holding on to old
elements for too long; the elements that have been popFronted by all ranges
are dropped from the cache according some heuristics.
cached was the main topic of Ali's DConf 2022 lightning
talk.
It caches the elements of its source range to ensure that the side effect of each generated element is applied only once:
auto r = iota(n)
.map!((i) {
arr ~= i; // <-- A side effect (adds to an array)
return i;
})
.cached // <-- Caches the generated elements
.filter!(i => true); // <-- The side effect is NOT repeatedcached provides a ForwardRange interface as well as random access to
elements even when the source range is an InputRange.
circularblocks was written for storing range elements of cached. It can be
used independently.
blockreusable was written as storage blocks for circularblocks. It can be
used independently.
errornogc was needed for throwing Errors from @nogc code. It can be used
independently.
test contains some helper utilities for unit testing.