50 lines
1.3 KiB
Scheme
50 lines
1.3 KiB
Scheme
#lang scheme/base
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(provide (all-defined-out))
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; just some stuff which is probably defined in standard schemish somewhere
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(define (assoc-remove k l)
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(cond
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((null? l) '())
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((eq? (car (car l)) k)
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(assoc-remove k (cdr l)))
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(else
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(cons (car l) (assoc-remove k (cdr l))))))
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(define (choose l)
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(list-ref l (random (length l))))
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(define (list-contains k l)
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(cond
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((null? l) #f)
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((eq? (car l) k) #t)
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(else (list-contains k (cdr l)))))
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(define (string-split s c)
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(define (_ sl tl cl)
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(cond
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((null? sl) (if (null? cl) tl (append tl (list (list->string cl)))))
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((eq? (car sl) c)
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(_ (cdr sl) (append tl (list (list->string cl))) '()))
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(else
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(_ (cdr sl) tl (append cl (list (car sl)))))))
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(_ (string->list s) '() '()))
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(define (list-string-concat l t)
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(cond
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((null? l) "")
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(else
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(string-append (car l) t (list-string-concat (cdr l) t)))))
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; returns a list of items in a but not in b
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(define (list-remainder a b)
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(cond
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((null? a) '())
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((not (list-contains (car a) b)) (cons (car a) (list-remainder (cdr a) b)))
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(else (list-remainder (cdr a) b))))
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(define (which-element k l n)
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(cond
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((null? l) #f)
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((eq? (car l) k) n)
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(else (which-element k (cdr l) (+ n 1))))) |