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0956f1839f
When I hit 999 exercises, I will finally have reached the ultimate state of soteriological release and no more exercises will be needed. The cycle will be complete. All that will be left is perfect quietude, freedom, and highest happiness.
55 lines
2.4 KiB
Zig
55 lines
2.4 KiB
Zig
//
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// You can also make pointers to multiple items without using a slice.
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//
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// var foo: [4]u8 = [4]u8{ 1, 2, 3, 4 };
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// var foo_slice: []u8 = foo[0..];
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// var foo_ptr: [*]u8 = &foo;
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//
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// The difference between foo_slice and foo_ptr is that the slice has
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// a known length. The pointer doesn't. It is up to YOU to keep track
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// of the number of u8s foo_ptr points to!
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//
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const std = @import("std");
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pub fn main() void {
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// Take a good look at the array type to which we're coercing
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// the zen12 string (the REAL nature of strings will be
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// revealed when we've learned some additional features):
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const zen12: *const [21]u8 = "Memory is a resource.";
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//
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// It would also have been valid to coerce to a slice:
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// const zen12: []const u8 = "...";
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//
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// Now let's turn this into a "many pointer":
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const zen_manyptr: [*]const u8 = zen12;
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// It's okay to access zen_manyptr just like an array or slice as
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// long as you keep track of the length yourself!
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//
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// A "string" in Zig is a pointer to an array of const u8 values
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// or a slice of const u8 values, into one, as we saw above). So,
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// we could treat a "many pointer" of const u8 a string as long
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// as we can CONVERT IT TO A SLICE. (Hint: we do know the length!)
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//
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// Please fix this line so the print below statement can print it:
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const zen12_string: []const u8 = zen_manyptr;
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// Here's the moment of truth!
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std.debug.print("{s}\n", .{zen12_string});
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}
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//
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// Are all of these pointer types starting to get confusing?
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//
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// FREE ZIG POINTER CHEATSHEET! (Using u8 as the example type.)
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// +---------------+----------------------------------------------+
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// | u8 | one u8 |
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// | *u8 | pointer to one u8 |
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// | [2]u8 | two u8s |
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// | [*]u8 | pointer to unknown number of u8s |
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// | [2]const u8 | two immutable u8s |
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// | [*]const u8 | pointer to unknown number of immutable u8s |
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// | *[2]u8 | pointer to an array of 2 u8s |
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// | *const [2]u8 | pointer to an immutable array of 2 u8s |
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// | []u8 | slice of u8s |
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// | []const u8 | slice of immutable u8s |
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// +---------------+----------------------------------------------+
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