{"id":"language--compute-dispatch","name":"Dispatch and computeTask","owner":"yeho","package":"language","kind":"language","signature":"computeTask job = dispatch Kernel(arguments)\nwait job\nwait until job.finished","description":"dispatch launches a compute function and returns a computeTask whose finished, failed, and error state can be inspected.","context":"Keep the task handle whenever later work depends on completion, failure, or measured execution.","parameters":[],"returns":"","members":[],"tags":["compute","computeTask","cpu","dispatch","error","failed","finished","gameplay","gpu","hybrid","language","pipeline","wait","yeho"],"updated":"2026-09-09","source":{"repository":"yeho","path":"parser_expressions.cpp parseDispatchStartExpression; accelerator runtime fixtures"},"status":"experimental","notes":["Compute dispatch shape and backend admission are validated.","A completed task can still represent a failed kernel; inspect failed when correctness depends on it."],"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.language__compute_dispatch\"\nversion = \"0.1.0\"\nlanguageEdition = \"yeho-core-2026.1\"\n\n[app]\nkind = \"headless\"\n","verification":"executed","sha256":"63da4f3f328e6d1c4f82afb54141936d76e04c5a5adc097461e5a41b48cea3fb","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.language__compute_dispatch\"\nversion = \"0.1.0\"\nlanguageEdition = \"yeho-core-2026.1\"\n\n[app]\nkind = \"headless\"\n","verification":"executed","sha256":"99561407893737681481c84de494d4808c0bbbc67c3765e855f0b75b494dfe30","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.language__compute_dispatch\"\nversion = \"0.1.0\"\nlanguageEdition = \"yeho-core-2026.1\"\n\n[app]\nkind = \"headless\"\n","verification":"executed","sha256":"dccdb19acc3dd74339210513eeeb8b926fc569959057acdb05fb1526991ff6fa","checked":"2026-09-09","diagnostic":"","observedOutput":"200","checkedBackend":"metal"}],"searchTerms":[],"url":"https://demonhunterlabs.com/academy/api?item=language--compute-dispatch","json":"https://demonhunterlabs.com/reference/items/language--compute-dispatch.json","markdown":"https://demonhunterlabs.com/reference/text/language--compute-dispatch.md"}