{"id":"word--buffer","name":"buffer","owner":"yeho","package":"runtime","kind":"runtime","signature":"buffer","description":"buffer in a complete program.","context":"CPU and GPU data processing with explicit ownership and completion.","parameters":[],"returns":"","members":[],"tags":["compute","cpu","gameplay","gpu","hybrid","pipeline","yeho"],"updated":"2026-09-09","source":{"repository":"yeho","path":"docs/runtime/execution-boundaries.md; docs/runtime/metal-compute-v1.md"},"status":"experimental","notes":[],"examples":[{"id":"cpu","title":"CPU · [cpu]","description":"Apply damage to a small batch of health values on the explicit CPU route. Each invocation owns one element.","code":"[cpu]\ncompute ApplyDamage(buffer of int health, int damage)\n{\n    int index = compute.index\n    if index >= health.count { return }\n    health[index] = health[index] - damage\n}\n\nbuffer of int health\nhealth.Add(100)\nhealth.Add(80)\nhealth.Add(60)\ncomputeTask job = dispatch ApplyDamage(health, 10)\nwait job\nif job.failed { Console.Error(job.error.message) Process.Exit(1) }\nfor index from 0 < health.count { Console.Log(Text.From(health[index])) }\n","tags":["cpu","compute","gameplay"],"run":"cpu-oracle","expected":"90\n70\n50","verifyRun":true,"manifest":"manifestVersion = \"2\"\npackage = \"api.example.word__buffer\"\nversion = \"0.1.0\"\nlanguageEdition = \"yeho-core-2026.1\"\n\n[app]\nkind = \"headless\"\n","verification":"executed","sha256":"a8c8621b356c4b34b3735f343bd93a775663fad789b2b0d568dccbd6b517dccc","checked":"2026-09-09","diagnostic":"","observedOutput":"90\n70\n50","checkedBackend":"cpu-oracle"},{"id":"gpu","title":"GPU · [gpu]","description":"Double a batch of reward values on native Metal. The [gpu] tag requires an accelerator backend; CPU oracle cannot silently satisfy it.","code":"[gpu]\ncompute DoubleRewards(buffer of int rewards, int multiplier)\n{\n    int index = compute.index\n    if index >= rewards.count { return }\n    rewards[index] = rewards[index] * multiplier\n}\n\nbuffer of int rewards\nrewards.Add(100)\nrewards.Add(80)\nrewards.Add(60)\ncomputeTask job = dispatch DoubleRewards(rewards, 2)\nwait job\nif job.failed { Console.Error(job.error.message) Process.Exit(1) }\nfor index from 0 < rewards.count { Console.Log(Text.From(rewards[index])) }\n","tags":["gpu","compute","gameplay"],"run":"metal","expected":"200\n160\n120","verifyRun":true,"manifest":"manifestVersion = \"2\"\npackage = \"api.example.word__buffer\"\nversion = \"0.1.0\"\nlanguageEdition = \"yeho-core-2026.1\"\n\n[app]\nkind = \"headless\"\n","verification":"executed","sha256":"940d73a7779dee386461a2a261cfad45c5b987cca30a050987c0315a42f9684e","checked":"2026-09-09","diagnostic":"","observedOutput":"200\n160\n120","checkedBackend":"metal"},{"id":"hybrid","title":"CPU + GPU · one pipeline","description":"The CPU prepares rewards, the GPU doubles them, then the CPU totals the finished buffer. There is no [both] tag. Ordinary host code and a [gpu] kernel cooperate explicitly.","code":"[gpu]\ncompute DoubleRewards(buffer of int rewards)\n{\n    int index = compute.index\n    if index >= rewards.count { return }\n    rewards[index] = rewards[index] * 2\n}\n\n// CPU: prepare a small game reward batch.\nbuffer of int rewards\nfor level from 1 <= 4 { rewards.Add(level * 10) }\n\n// GPU: process independent elements.\ncomputeTask job = dispatch DoubleRewards(rewards)\nwait job\nif job.failed { Console.Error(job.error.message) Process.Exit(1) }\n\n// CPU: consume only after the GPU has finished.\nint total = 0\nfor index from 0 < rewards.count { total = total + rewards[index] }\nConsole.Log(Text.From(total))\n","tags":["hybrid","cpu","gpu","compute","pipeline"],"run":"metal","expected":"200","verifyRun":true,"manifest":"manifestVersion = \"2\"\npackage = \"api.example.word__buffer\"\nversion = \"0.1.0\"\nlanguageEdition = \"yeho-core-2026.1\"\n\n[app]\nkind = \"headless\"\n","verification":"executed","sha256":"b534b6ac2692e5ee20a34183547e29bcbea3bf36d575780366086b0533931965","checked":"2026-09-09","diagnostic":"","observedOutput":"200","checkedBackend":"metal"}],"searchTerms":[],"url":"https://demonhunterlabs.com/academy/api?item=word--buffer","json":"https://demonhunterlabs.com/reference/items/word--buffer.json","markdown":"https://demonhunterlabs.com/reference/text/word--buffer.md"}