| ... | ... | @@ -2355,11 +2355,18 @@ fn eventuallyErrorSequence() error!u32 { |
| 2355 | 2355 | break :blk numbers_left; |
| 2356 | 2356 | }; |
| 2357 | 2357 | } |
| 2358 | {#code_end#} |
| 2359 | |
| 2360 | {#header_open|inline while#} |
| 2361 | <p> |
| 2362 | While loops can be inlined. This causes the loop to be unrolled, which |
| 2363 | allows the code to do some things which only work at compile time, |
| 2364 | such as use types as first class values. |
| 2365 | </p> |
| 2366 | {#code_begin|test#} |
| 2367 | const assert = @import("std").debug.assert; |
| 2358 | 2368 | |
| 2359 | 2369 | test "inline while loop" { |
| 2360 | | // While loops can be inlined. This causes the loop to be unrolled, which |
| 2361 | | // allows the code to do some things which only work at compile time, |
| 2362 | | // such as use types as first class values. |
| 2363 | 2370 | comptime var i = 0; |
| 2364 | 2371 | var sum: usize = 0; |
| 2365 | 2372 | inline while (i < 3) : (i += 1) { |
| ... | ... | @@ -2378,6 +2385,16 @@ fn typeNameLength(comptime T: type) usize { |
| 2378 | 2385 | return @typeName(T).len; |
| 2379 | 2386 | } |
| 2380 | 2387 | {#code_end#} |
| 2388 | <p> |
| 2389 | It is recommended to use <code>inline</code> loops only for one of these reasons: |
| 2390 | </p> |
| 2391 | <ul> |
| 2392 | <li>You need the loop to execute at {#link|comptime#} for the semantics to work.</li> |
| 2393 | <li> |
| 2394 | You have a benchmark to prove that forcibly unrolling the loop in this way is measurably faster. |
| 2395 | </li> |
| 2396 | </ul> |
| 2397 | {#header_close#} |
| 2381 | 2398 | {#see_also|if|Optionals|Errors|comptime|unreachable#} |
| 2382 | 2399 | {#header_close#} |
| 2383 | 2400 | {#header_open|for#} |
| ... | ... | @@ -2445,15 +2462,20 @@ test "for else" { |
| 2445 | 2462 | break :blk sum; |
| 2446 | 2463 | }; |
| 2447 | 2464 | } |
| 2448 | | |
| 2465 | {#code_end#} |
| 2466 | {#header_open|inline for#} |
| 2467 | <p> |
| 2468 | For loops can be inlined. This causes the loop to be unrolled, which |
| 2469 | allows the code to do some things which only work at compile time, |
| 2470 | such as use types as first class values. |
| 2471 | The capture value and iterator value of inlined for loops are |
| 2472 | compile-time known. |
| 2473 | </p> |
| 2474 | {#code_begin|test#} |
| 2475 | const assert = @import("std").debug.assert; |
| 2449 | 2476 | |
| 2450 | 2477 | test "inline for loop" { |
| 2451 | 2478 | const nums = []i32{2, 4, 6}; |
| 2452 | | // For loops can be inlined. This causes the loop to be unrolled, which |
| 2453 | | // allows the code to do some things which only work at compile time, |
| 2454 | | // such as use types as first class values. |
| 2455 | | // The capture value and iterator value of inlined for loops are |
| 2456 | | // compile-time known. |
| 2457 | 2479 | var sum: usize = 0; |
| 2458 | 2480 | inline for (nums) |i| { |
| 2459 | 2481 | const T = switch (i) { |
| ... | ... | @@ -2471,6 +2493,16 @@ fn typeNameLength(comptime T: type) usize { |
| 2471 | 2493 | return @typeName(T).len; |
| 2472 | 2494 | } |
| 2473 | 2495 | {#code_end#} |
| 2496 | <p> |
| 2497 | It is recommended to use <code>inline</code> loops only for one of these reasons: |
| 2498 | </p> |
| 2499 | <ul> |
| 2500 | <li>You need the loop to execute at {#link|comptime#} for the semantics to work.</li> |
| 2501 | <li> |
| 2502 | You have a benchmark to prove that forcibly unrolling the loop in this way is measurably faster. |
| 2503 | </li> |
| 2504 | </ul> |
| 2505 | {#header_close#} |
| 2474 | 2506 | {#see_also|while|comptime|Arrays|Slices#} |
| 2475 | 2507 | {#header_close#} |
| 2476 | 2508 | {#header_open|if#} |
| ... | ... | @@ -4222,13 +4254,8 @@ pub fn main() void { |
| 4222 | 4254 | task in userland. It does so without introducing another language on top of Zig, such as |
| 4223 | 4255 | a macro language or a preprocessor language. It's Zig all the way down. |
| 4224 | 4256 | </p> |
| 4225 | | <p>TODO: suggestion to not use inline unless necessary</p> |
| 4226 | | {#header_close#} |
| 4227 | 4257 | {#header_close#} |
| 4228 | | {#header_open|inline#} |
| 4229 | | <p>TODO: inline while</p> |
| 4230 | | <p>TODO: inline for</p> |
| 4231 | | <p>TODO: suggestion to not use inline unless necessary</p> |
| 4258 | {#see_also|inline while|inline for#} |
| 4232 | 4259 | {#header_close#} |
| 4233 | 4260 | {#header_open|Assembly#} |
| 4234 | 4261 | <p>TODO: example of inline assembly</p> |
Andrew Kelley <andrew@ziglang.org> 2018-06-19 17:21:08-04:00