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41 lines
992 B
Racket
41 lines
992 B
Racket
#lang br/quicklang
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(require brag/support)
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(module+ reader
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(provide read-syntax))
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(define lex
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(lexer
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["#$" null]
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["%" 'taco]
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[any-char (lex input-port)]))
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(define (tokenize ip)
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(for/list ([tok (in-port lex ip)])
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tok))
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(define (parse src toks)
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(define heptatoks
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(let loop ([toks toks][acc null])
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(if (empty? toks)
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(reverse acc)
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(loop (drop toks 7) (cons (take toks 7) acc)))))
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(for/list ([heptatok (in-list heptatoks)])
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(integer->char
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(for/sum ([val (in-list heptatok)]
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[power (in-naturals)]
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#:when (eq? val 'taco))
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(expt 2 power)))))
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(define (read-syntax src ip)
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(define toks (tokenize ip))
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(define parse-tree (parse src toks))
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(strip-context
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(with-syntax ([PT parse-tree])
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#'(module taco-mod tacopocalypse-demo
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PT))))
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(define-macro (my-module-begin PT)
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#'(#%module-begin
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(display (list->string 'PT))))
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(provide (rename-out [my-module-begin #%module-begin])) |