diff --git a/exercises/028_defer2.zig b/exercises/028_defer2.zig index 35c1326..b490a89 100644 --- a/exercises/028_defer2.zig +++ b/exercises/028_defer2.zig @@ -10,6 +10,8 @@ pub fn main() void { for (animals) |a| printAnimal(a); std.debug.print("done.\n", .{}); + + std.debug.print("Answer to everything? {d}\n", .{calculateTheUltimateQuestionOfLife()}); } // This function is _supposed_ to print an animal name in parentheses @@ -35,3 +37,24 @@ fn printAnimal(animal: u8) void { std.debug.print("Unknown", .{}); } + +// This function is supposed to calculate the answer to the +// ultimate question of life, the universe, and everything, +// but it needs to be deferred as far in the future as possible, +// in order to gather more data. +// +// When there are multiple defers in a single block, they are executed in reverse order. +// This example might seem silly, but it's important to know when e.g. +// deinitializing containers whose elements need to be deinitialized first. +fn calculateTheUltimateQuestionOfLife() u32 { + var x: u32 = 100; + + // Try reordering the statements to get the answer 42 + { + defer x = x / 10; + defer x = x + 11; + defer x = x * 2; + } + + return x; +} diff --git a/patches/patches/028_defer2.patch b/patches/patches/028_defer2.patch index f09b1e5..28eb806 100644 --- a/patches/patches/028_defer2.patch +++ b/patches/patches/028_defer2.patch @@ -1,6 +1,6 @@ ---- exercises/028_defer2.zig 2023-10-03 22:15:22.122241138 +0200 -+++ answers/028_defer2.zig 2023-10-05 20:04:06.966098530 +0200 -@@ -18,7 +18,7 @@ +--- exercises/028_defer2.zig 2026-06-02 06:08:12.713672612 +0200 ++++ answers/028_defer2.zig 2026-06-02 06:08:43.262234023 +0200 +@@ -20,7 +20,7 @@ fn printAnimal(animal: u8) void { std.debug.print("(", .{}); @@ -9,3 +9,15 @@ if (animal == 'g') { std.debug.print("Goat", .{}); +@@ -51,9 +51,9 @@ + + // Try reordering the statements to get the answer 42 + { +- defer x = x / 10; +- defer x = x + 11; + defer x = x * 2; ++ defer x = x + 11; ++ defer x = x / 10; + } + + return x; diff --git a/src/elrond.zig b/src/elrond.zig index 35c8857..716f546 100644 --- a/src/elrond.zig +++ b/src/elrond.zig @@ -693,7 +693,10 @@ const exercises = [_]Exercise{ }, .{ .main_file = "028_defer2.zig", - .output = "(Goat) (Cat) (Dog) (Dog) (Goat) (Unknown) done.", + .output = + \\(Goat) (Cat) (Dog) (Dog) (Goat) (Unknown) done. + \\Answer to everything? 42 + , // pay attention to the comma }, .{ .main_file = "029_errdefer.zig",