29 lines
965 B
Scheme
29 lines
965 B
Scheme
#lang scheme/base
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(provide nest)
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;; A form that makes it easy to combine many "right-drifting" nested
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;; expressions into a single one, sort of like a generalized version of the `*'
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;; from `let*' and similar forms.
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(define-syntax nest
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(syntax-rules ()
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[(nest () body0 body ...)
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(let () body0 body ...)]
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;; this allows putting definitions in the body
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[(nest ([form forms ...]) body0 body ...)
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(form forms ... (let () body0 body ...))]
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[(nest ([form forms ...] . more) body0 body ...)
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(form forms ... (nest more body0 body ...))]))
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;; using this instead will allow splicing body expressions in the last form
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;; whatever it happens to be, which can be (ab)used in strange ways
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#;
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(define-syntax nest
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(syntax-rules ()
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[(nest () body ...)
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(begin body ...)]
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[(nest ([form forms ...]) body ...)
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(form forms ... body ...)]
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[(nest ([form forms ...] . more) body ...)
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(form forms ... (nest more body ...))]))
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