39 lines
1.1 KiB
Nim
39 lines
1.1 KiB
Nim
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# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
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# SPDX-License-Identifier: Unlicense
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import std/tables
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from std/macros import hasCustomPragma, getCustomPragmaVal
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import preserves
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import ../syndicate/protocols/[dataspacePatterns]
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from ./actors import Ref
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type
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Pattern* = dataspacePatterns.Pattern[Ref]
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proc bindDiscard(): Pattern =
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Pattern(
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orKind: PatternKind.DBind,
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dbind: DBind[Ref](
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pattern: Pattern(
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orKind: PatternKind.DDiscard)))
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proc toPattern*(T: typedesc): Pattern =
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when T.hasCustomPragma(preservesRecord):
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let label = tosymbol(T.getCustomPragmaVal(preservesRecord), Ref)
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var
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arity: BiggestInt
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members: Table[BiggestInt, Pattern]
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t: ptr T # a hack to iterate the fields of a non-existent instance
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for _ in fields(t[]):
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members[arity] = bindDiscard()
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inc arity
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result = Pattern(
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orKind: PatternKind.DCompound,
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dcompound: DCompound[Ref](
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orKind: DCompoundKind.rec,
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rec: DCompoundRec[Ref](
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ctor: CRec[Ref](label: label, arity: arity),
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members: members)))
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