| 1 | #include "generator.h" |
| 2 | #include "coroutine.h" |
| 3 | #include <stdlib.h> |
| 4 | #include <stdio.h> |
| 5 | #include <assert.h> |
| 6 | |
| 7 | enum { |
| 8 | Generator_Running, |
| 9 | Generator_Deleting, |
| 10 | Generator_Complete |
| 11 | }; |
| 12 | |
| 13 | struct Generator { |
| 14 | Coroutine *coroutine; |
| 15 | Coroutine *caller; |
| 16 | void *(*start)(void *); |
| 17 | void *param; |
| 18 | char state; |
| 19 | }; |
| 20 | |
| 21 | static void on_yield(void *this){ |
| 22 | Generator *gen = (Generator *)this; |
| 23 | Coroutine_Continue(gen->caller, Coroutine_GetValue(gen->coroutine), true); |
| 24 | } |
| 25 | |
| 26 | static void *do_start(void *this){ |
| 27 | Generator *gen = (Generator *)this; |
| 28 | assert(gen->state == Generator_Running || gen->state == Generator_Deleting); |
| 29 | void *value; |
| 30 | if (gen->state == Generator_Running){ |
| 31 | value = gen->start(gen->param); |
| 32 | } else { |
| 33 | // we are being deleted |
| 34 | value = NULL; |
| 35 | } |
| 36 | gen->state = Generator_Complete; |
| 37 | Coroutine_Continue(gen->caller, value, true); |
| 38 | return value; |
| 39 | } |
| 40 | |
| 41 | Generator *Generator_New(void *(*start)(void *), void *param){ |
| 42 | Generator *gen = malloc(sizeof(Generator)); |
| 43 | gen->start = start; |
| 44 | gen->param = param; |
| 45 | gen->coroutine = Coroutine_New(gen, on_yield, do_start); |
| 46 | gen->state = Generator_Running; |
| 47 | return gen; |
| 48 | } |
| 49 | |
| 50 | void Generator_Delete(Generator *gen){ |
| 51 | assert(gen->state != Generator_Deleting); |
| 52 | if (gen->state == Generator_Running){ |
| 53 | gen->state = Generator_Deleting; |
| 54 | gen->caller = Coroutine_GetActive(); |
| 55 | Coroutine_Continue(gen->coroutine, gen, true); |
| 56 | Coroutine_Yield(NULL); |
| 57 | } |
| 58 | assert(gen->state == Generator_Complete); |
| 59 | Coroutine_Delete(gen->coroutine); |
| 60 | free(gen); |
| 61 | } |
| 62 | |
| 63 | bool Generator_Next(Generator *gen, void **value){ |
| 64 | assert(gen->state != Generator_Deleting); |
| 65 | if (gen->state == Generator_Complete){ |
| 66 | return false; |
| 67 | } |
| 68 | gen->caller = Coroutine_GetActive(); |
| 69 | Coroutine_Continue(gen->coroutine, gen, true); |
| 70 | *value = Coroutine_Yield(NULL); |
| 71 | return Coroutine_IsRunning(gen->coroutine); |
| 72 | } |
| 73 | |
| 74 | bool Generator_Yield(void *value) |
| 75 | { |
| 76 | Generator *gen = Coroutine_Yield(value); |
| 77 | return gen->state == Generator_Running; |
| 78 | } |
| 79 | |