25 lines
892 B
Plaintext
25 lines
892 B
Plaintext
module desugar
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imports libstrategolib signatures/-
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rules
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/* ISequence() and Prior() are just noise for more expressions in sequence,
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put in to get the layout rules right. So we remove them and collapse
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all occurrence of them into one big Sequence() call on a list.
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This is slightly tricky because there might not be any Sequence() call
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at the top level, but yet an ISequence(). So we do it in two passes,
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first converting ISequence()s to Sequence()s, and then collapsing
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Sequence()s.
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*/
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deISe: ISequence(Prior(l),x) -> Sequence(<conc>(l, [x]))
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seqFlatten: Sequence(l) -> Sequence(<mapconcat(?Sequence(<id>) <+ ![<id>])>l)
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defStream: DefGets(x) -> Gets(Stream(), x)
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defStream: DefTo(x) -> To(x, Stream())
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defStream: DefEmits() -> Emits(Stream())
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strategies
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desugar-fostr = bottomup(try(defStream <+ deISe <+ seqFlatten))
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