From 0168afd25005b4a3555d2212d2a099cbad344e2b Mon Sep 17 00:00:00 2001 From: Dave Gauer Date: Sun, 7 Mar 2021 10:08:07 -0500 Subject: "Multi pointers" are now "many pointers" TypeInfo.Pointer.Size says "many", so there we are! --- README.md | 2 +- build.zig | 2 +- exercises/54_manypointers.zig | 53 ++++++++++++++++++++++++++++++++++ exercises/54_multipointers.zig | 53 ---------------------------------- patches/patches/54_manypointers.patch | 4 +++ patches/patches/54_multipointers.patch | 4 --- 6 files changed, 59 insertions(+), 59 deletions(-) create mode 100644 exercises/54_manypointers.zig delete mode 100644 exercises/54_multipointers.zig create mode 100644 patches/patches/54_manypointers.patch delete mode 100644 patches/patches/54_multipointers.patch diff --git a/README.md b/README.md index 73793c8..cd4f397 100644 --- a/README.md +++ b/README.md @@ -129,7 +129,7 @@ Planned exercises: * [x] Optionals * [x] Struct methods * [x] Slices -* [x] Multi pointers +* [x] Many pointers * [ ] Unions * [ ] Numeric types (integers, floats) * [ ] Labelled blocks and loops diff --git a/build.zig b/build.zig index 789024b..75fa9a9 100644 --- a/build.zig +++ b/build.zig @@ -277,7 +277,7 @@ const exercises = [_]Exercise{ .output = "'all your base are belong to us.' 'for great justice.'", }, .{ - .main_file = "54_multipointers.zig", + .main_file = "54_manypointers.zig", .output = "Memory is a resource.", }, }; diff --git a/exercises/54_manypointers.zig b/exercises/54_manypointers.zig new file mode 100644 index 0000000..05edd3b --- /dev/null +++ b/exercises/54_manypointers.zig @@ -0,0 +1,53 @@ +// +// You can also make pointers to multiple items without using a slice. +// +// var foo: [4]u8 = [4]u8{ 1, 2, 3, 4 }; +// var foo_slice: []u8 = foo[0..]; +// var foo_ptr: [*]u8 = &foo; +// +// The difference between foo_slice and foo_ptr is that the slice has +// a known length. The pointer doesn't. It is up to YOU to keep track +// of the number of u8s foo_ptr points to! +// +const std = @import("std"); + +pub fn main() void { + // Take a good look at the type of the zen12 string: + const zen12: *const [21]u8 = "Memory is a resource."; + // It would also have been valid to coerce this to a slice: + // + // const zen12: []const u8 = "..."; + // + // Now let's turn this into a "many pointer": + const zen_manyptr: [*]const u8 = zen12; + + // It's okay to access zen_manyptr just like an array or slice as + // long as you keep track of the length yourself! + // + // A "string" in Zig is a pointer to an array of const u8 values + // or a slice of const u8 values, into one, as we saw above). So, + // we could treat a "many pointer" of const u8 a string as long + // as we can CONVERT IT TO A SLICE. (Hint: we do know the length!) + // + // Please fix this line so the print below statement can print it: + const zen12_string: []const u8 = zen_manyptr; + + // Here's the moment of truth! + std.debug.print("{s}\n", .{zen12_string}); +} +// +// Are all of these pointer types starting to get confusing? +// +// FREE ZIG POINTER CHEATSHEET! (Using u8 as the example type.) +// +---------------+----------------------------------------------+ +// | u8 | one u8 | +// | *u8 | pointer to one u8 | +// | [2]u8 | two u8s | +// | [*]u8 | pointer to unknown number of u8s | +// | [2]const u8 | two immutable u8s | +// | [*]const u8 | pointer to unknown number of immutable u8s | +// | *[2]u8 | pointer to an array of 2 u8s | +// | *const [2]u8 | pointer to an immutable array of 2 u8s | +// | []u8 | slice of u8s | +// | []const u8 | slice of immutable u8s | +// +---------------+----------------------------------------------+ diff --git a/exercises/54_multipointers.zig b/exercises/54_multipointers.zig deleted file mode 100644 index b6fb1f7..0000000 --- a/exercises/54_multipointers.zig +++ /dev/null @@ -1,53 +0,0 @@ -// -// You can also make pointers to multiple items without using a slice. -// -// var foo: [4]u8 = [4]u8{ 1, 2, 3, 4 }; -// var foo_slice: []u8 = foo[0..]; -// var foo_ptr: [*]u8 = &foo; -// -// The difference between foo_slice and foo_ptr is that the slice has -// a known length. The pointer doesn't. It is up to YOU to keep track -// of the number of u8s foo_ptr points to! -// -const std = @import("std"); - -pub fn main() void { - // Take a good look at the type of the zen12 string: - const zen12: *const [21]u8 = "Memory is a resource."; - // It would also have been valid to coerce this to a slice: - // - // const zen12: []const u8 = "..."; - // - // Now let's turn this into a "multi pointer": - const zen_multiptr: [*]const u8 = zen12; - - // It's okay to access zen_multiptr just like an array or slice as - // long as you keep track of the length yourself! - // - // A "string" in Zig is a pointer to an array of const u8 values - // or a slice of const u8 values, into one, as we saw above). So, - // we could treat a "multi pointer" of const u8 a string as long - // as we can CONVERT IT TO A SLICE. (Hint: we do know the length!) - // - // Please fix this line so the print below statement can print it: - const zen12_string: []const u8 = zen_multiptr; - - // Here's the moment of truth! - std.debug.print("{s}\n", .{zen12_string}); -} -// -// Are all of these pointer types starting to get confusing? -// -// FREE ZIG POINTER CHEATSHEET! (Using u8 as the example type.) -// +---------------+----------------------------------------------+ -// | u8 | one u8 | -// | *u8 | pointer to one u8 | -// | [2]u8 | two u8s | -// | [*]u8 | pointer to unknown number of u8s | -// | [2]const u8 | two immutable u8s | -// | [*]const u8 | pointer to unknown number of immutable u8s | -// | *[2]u8 | pointer to an array of 2 u8s | -// | *const [2]u8 | pointer to an immutable array of 2 u8s | -// | []u8 | slice of u8s | -// | []const u8 | slice of immutable u8s | -// +---------------+----------------------------------------------+ diff --git a/patches/patches/54_manypointers.patch b/patches/patches/54_manypointers.patch new file mode 100644 index 0000000..82824e8 --- /dev/null +++ b/patches/patches/54_manypointers.patch @@ -0,0 +1,4 @@ +33c33 +< const zen12_string: []const u8 = zen_manyptr; +--- +> const zen12_string: []const u8 = zen_manyptr[0..21]; diff --git a/patches/patches/54_multipointers.patch b/patches/patches/54_multipointers.patch deleted file mode 100644 index 84d3f14..0000000 --- a/patches/patches/54_multipointers.patch +++ /dev/null @@ -1,4 +0,0 @@ -33c33 -< const zen12_string: []const u8 = zen_multiptr; ---- -> const zen12_string: []const u8 = zen_multiptr[0..21]; -- cgit v1.2.3-ZIG