From 36116fc1ba8edc32b344607f4c6aa0c47d27f88d Mon Sep 17 00:00:00 2001 From: Basti Ortiz <39114273+BastiDood@users.noreply.github.com> Date: Tue, 22 Oct 2024 07:16:17 +0800 Subject: [PATCH] docs(effect): clarify example on dynamic dependency tracking --- documentation/docs/02-runes/04-$effect.md | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/documentation/docs/02-runes/04-$effect.md b/documentation/docs/02-runes/04-$effect.md index eedca52d9d43..aeaa31d6b2d7 100644 --- a/documentation/docs/02-runes/04-$effect.md +++ b/documentation/docs/02-runes/04-$effect.md @@ -125,7 +125,11 @@ An effect only reruns when the object it reads changes, not when a property insi

{state.value} doubled is {derived.value}

``` -An effect only depends on the values that it read the last time it ran. If `a` is true, changes to `b` will [not cause this effect to rerun](/playground/untitled#H4sIAAAAAAAAE3WQ0WrDMAxFf0U1hTow1vcsMfQ7lj3YjlxEXTvEymC4_vfFC6Ewtidxde8RkrJw5DGJ9j2LoO8oWnGZJvEi-GuqIn2iZ1x1istsa6dLdqaJ1RAG9sigoYdjYs0onfYJm7fdMX85q3dE59CylA30CnJtDWxjSNHjq49XeZqXEChcT9usLUAOpIbHA0yzM78oColGhDVofLS3neZSS6mqOz-XD51ZmGOAGKwne-vztk-956CL0kAJsi7decupf4l658EUZX4I8yTWt93jSI5wFC3PC5aP8g0Aje5DcQEAAA==): +An effect only depends on the values that it read the last time it ran. This implementation detail has interesting implications for effects that have conditional short-circuiting code. + +For instance, if `a` is `false` in the code snippet below, the `a || b` operation will proceed to read `a` and _then_ `b`. This double read causes the effect to depend on both `a` and `b`, which in turn causes the effect to rerun whenever any of `a` or `b` change. + +On the other hand, if `a` is `true`, changes to `b` will [not cause this effect to rerun](/#H4sIAAAAAAAAE3WQ0WrDMAxFf0U1hTow1vcsMfQ7lj3YjlxEXTvEymC4_vfFC6Ewtidxde8RkrJw5DGJ9j2LoO8oWnGZJvEi-GuqIn2iZ1x1istsa6dLdqaJ1RAG9sigoYdjYs0onfYJm7fdMX85q3dE59CylA30CnJtDWxjSNHjq49XeZqXEChcT9usLUAOpIbHA0yzM78oColGhDVofLS3neZSS6mqOz-XD51ZmGOAGKwne-vztk-956CL0kAJsi7decupf4l658EUZX4I8yTWt93jSI5wFC3PC5aP8g0Aje5DcQEAAA==) because the `a || b` operation _exits early_ as soon as it encounters the first truthy operand. By exiting early, the effect will have only read `a`, which causes the effect to _only_ depend on `a`, not `b`. ```ts let a = false;