diff options
| author | Chris Boesch <chrboesch@noreply.codeberg.org> | 2026-06-21 16:16:31 +0200 |
|---|---|---|
| committer | Chris Boesch <chrboesch@noreply.codeberg.org> | 2026-06-21 16:16:31 +0200 |
| commit | cbcb570248a5297a0644fc22357bf81aac54545a (patch) | |
| tree | eb0e8ab53bfd9b8d65d24337c4193a48b88823c3 | |
| parent | f3df08d8e05dc0543137ae9866b389df178b97c6 (diff) | |
expanded explanation about self vs *self
| -rw-r--r-- | exercises/047_methods.zig | 18 | ||||
| -rw-r--r-- | patches/patches/047_methods.patch | 6 |
2 files changed, 21 insertions, 3 deletions
diff --git a/exercises/047_methods.zig b/exercises/047_methods.zig index 3221ca2..3e88719 100644 --- a/exercises/047_methods.zig +++ b/exercises/047_methods.zig @@ -37,6 +37,24 @@ // self, others use a lowercase version of the type name, but feel // free to use whatever is most appropriate. // +// "But hold on," you say, eyeing a() and b() suspiciously, "why +// does one take 'self' and another take '*self'?" Sharp eye! +// +// It all comes down to a single question: does the function need +// to CHANGE the struct? +// +// * Needs to change it? Take a pointer (*Bar). Without it you'd +// be scribbling on a COPY, and your changes would evaporate the +// instant the function returns. Poof. +// * Only reads it? Plain Bar is just fine. +// (For a big, bulky struct you might still write *const Bar to +// avoid copying it around, but for small ones a copy is cheap.) +// +// You'll see this below: zap() takes 'self: HeatRay' by value +// because it only reads the ray's damage, but it takes the alien +// as '*Alien' because zapping is supposed to HURT - and that means +// changing the alien's health for real, not on a throwaway copy. +// // Okay, you're armed. // // Now, please zap the alien structs until they're all gone or diff --git a/patches/patches/047_methods.patch b/patches/patches/047_methods.patch index a7e8a26..4755ecb 100644 --- a/patches/patches/047_methods.patch +++ b/patches/patches/047_methods.patch @@ -1,6 +1,6 @@ ---- exercises/047_methods.zig 2023-10-03 22:15:22.122241138 +0200 -+++ answers/047_methods.zig 2023-10-05 20:04:07.056100214 +0200 -@@ -88,7 +88,7 @@ +--- exercises/047_methods.zig 2026-06-21 16:11:59.110876971 +0200 ++++ answers/047_methods.zig 2026-06-21 16:13:07.066363558 +0200 +@@ -106,7 +106,7 @@ for (&aliens) |*alien| { // *** Zap the alien with the heat ray here! *** |