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49 lines
1.4 KiB
Racket
49 lines
1.4 KiB
Racket
8 years ago
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#lang racket/base
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(require (for-syntax racket/base syntax/parse))
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(provide #%module-begin
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;; We reuse Racket's treatment of raw datums, specifically
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;; for strings and numbers:
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#%datum
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;; And otherwise, we provide definitions of these three forms.
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;; During compiliation, Racket uses these definitions to
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;; rewrite into for loops, displays, and newlines.
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drawing rows chunk)
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;; Define a few compile-time functions to do the syntax rewriting:
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(begin-for-syntax
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(define (compile-drawing drawing-stx)
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(syntax-parse drawing-stx
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[({~literal drawing} row-stxs ...)
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(syntax/loc drawing-stx
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(begin row-stxs ...))]))
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(define (compile-rows row-stx)
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(syntax-parse row-stx
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[({~literal rows}
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({~literal repeat} repeat-number)
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chunks ...
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";")
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(syntax/loc row-stx
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(for ([i repeat-number])
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chunks ...
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(newline)))]))
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(define (compile-chunk chunk-stx)
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(syntax-parse chunk-stx
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[({~literal chunk} chunk-size chunk-string)
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(syntax/loc chunk-stx
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(for ([k chunk-size])
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(display chunk-string)))])))
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;; Wire up the use of "drawing", "rows", and "chunk" to these
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;; transformers:
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(define-syntax drawing compile-drawing)
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(define-syntax rows compile-rows)
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(define-syntax chunk compile-chunk)
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