53 lines
1.5 KiB
Nim
53 lines
1.5 KiB
Nim
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import # system libs
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tables
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import # deps
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uuids
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type
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Args* = ref object of RootObj # ...args
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Handler* = proc (args: Args) {.closure.} # callback function type
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EventEmitter* = ref object
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events: Table[string, Table[UUID, Handler]]
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proc createEventEmitter*(): EventEmitter =
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result.new
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result.events = initTable[string, Table[UUID, Handler]]()
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proc on(this: EventEmitter, name: string, handlerId: UUID, handler: Handler): void =
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if this.events.hasKey(name):
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this.events[name].add handlerId, handler
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return
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this.events[name] = [(handlerId, handler)].toTable
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proc on*(this: EventEmitter, name: string, handler: Handler): void =
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var uuid: UUID
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this.on(name, uuid, handler)
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proc once*(this:EventEmitter, name:string, handler:Handler): void =
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var handlerId = genUUID()
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this.on(name, handlerId) do(a: Args):
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handler(a)
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this.events[name].del handlerId
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proc emit*(this:EventEmitter, name:string, args:Args): void =
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if this.events.hasKey(name):
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for (id, handler) in this.events[name].pairs:
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handler(args)
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when isMainModule:
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block:
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type ReadyArgs = ref object of Args
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text: string
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var evts = createEventEmitter()
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evts.on("ready") do(a: Args):
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var args = ReadyArgs(a)
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echo args.text, ": from [1st] handler"
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evts.once("ready") do(a: Args):
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var args = ReadyArgs(a)
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echo args.text, ": from [2nd] handler"
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evts.emit("ready", ReadyArgs(text:"Hello, World"))
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evts.emit("ready", ReadyArgs(text:"Hello, World"))
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