diff --git a/readability.rkt b/readability.rkt deleted file mode 100644 index 219a83b..0000000 --- a/readability.rkt +++ /dev/null @@ -1,343 +0,0 @@ -#lang racket/base -(require racket/contract net/url xml) -(require (only-in racket/list empty? range splitf-at dropf dropf-right)) -(require (only-in racket/format ~a)) -(require (only-in racket/string string-join)) -(require (only-in racket/vector vector-member)) -(require (only-in racket/set set set->list set?)) -(module+ test (require rackunit)) -(require "debug.rkt") - -(provide (all-defined-out)) - -;; general way of coercing to integer -(define/contract (->int x) - (any/c . -> . integer?) - (cond - [(integer? x) x] - [(real? x) (floor x)] - [(and (string? x) (> (len x) 0)) (->int (string->number x))] - [(symbol? x) (->int (->string x))] - [(char? x) (char->integer x)] - [(has-length? x) (len x)] - [else (error "Can't convert to integer:" x)])) - - -;; general way of coercing to string -(define/contract (->string x) - (any/c . -> . string?) - (cond - [(string? x) x] - [(empty? x) ""] - [(symbol? x) (symbol->string x)] - [(number? x) (number->string x)] - [(url? x) (->string (->path x))] ; todo: a url is more than just a path-string ... it has character encoding issues - [(path? x) (path->string x)] - [(char? x) (~a x)] - [(xexpr? x) (xexpr->string x)] ; put this last so other xexprish things don't get caught - [else (error (format "Can't make ~a into string" x))])) - -(module+ test - (check-equal? (->string "foo") "foo") - (check-equal? (->string '()) "") - (check-equal? (->string 'foo) "foo") - (check-equal? (->string 123) "123") - (check-equal? (->string (string->url "foo/bar.html")) "foo/bar.html") - (define file-name-as-text "foo.txt") - (check-equal? (->string (string->path file-name-as-text)) file-name-as-text) - (check-equal? (->string #\¶) "¶") - (check-equal? (->string '(foo "bar")) "bar")) - - -;; general way of coercing to symbol -(define (->symbol thing) - ; todo: on bad input, it will pop a string error rather than symbol error - (string->symbol (->string thing))) - -;; general way of coercing to path -(define/contract (->path thing) - (any/c . -> . path?) - ; todo: on bad input, it will pop a string error rather than path error - (cond - [(url? thing) (apply build-path (map path/param-path (url-path thing)))] - [else (string->path (->string thing))])) - -(module+ test - (check-equal? (->path "foo") (string->path "foo")) - (check-equal? (->path 'foo) (string->path "foo")) - (check-equal? (->path 123) (string->path "123")) - (check-equal? (->path (string->url "foo/bar.html")) (string->path "foo/bar.html"))) - -;; general way of coercing to url -(define/contract (->url thing) - (any/c . -> . url?) - ; todo: on bad input, it will pop a string error rather than url error - (string->url (->string thing))) - -(define (->complete-path thing) - (path->complete-path (->path thing))) - - -;; general way of coercing to a list -(define/contract (->list x) - (any/c . -> . list?) - (cond - [(list? x) x] - [(vector? x) (vector->list x)] - [(set? x) (set->list x)] - [else (list x)])) - -(module+ test - (check-equal? (->list '(1 2 3)) '(1 2 3)) - (check-equal? (->list (list->vector '(1 2 3))) '(1 2 3)) - (check-equal? (->list (set 1 2 3)) '(3 2 1)) - (check-equal? (->list "foo") (list "foo"))) - -;; general way of coercing to vector -(define (->vector x) - (any/c . -> . vector?) - ; todo: on bad input, it will pop a list error rather than vector error - (cond - [(vector? x) x] - [else (list->vector (->list x))])) - - - -;; general way of coercing to boolean -(define/contract (->boolean x) - (any/c . -> . boolean?) - ;; in Racket, everything but #f is true - (if x #t #f)) - -(module+ test - (check-true (->boolean #t)) - (check-false (->boolean #f)) - (check-true (->boolean "#f")) - (check-true (->boolean "foo")) - (check-true (->boolean '())) - (check-true (->boolean '(1 2 3)))) - - -(define/contract (has-length? x) - (any/c . -> . boolean?) - (ormap (λ(proc) (proc x)) (list list? string? symbol? vector? hash? set?))) - -;; general way of asking for length -(define/contract (len x) - (has-length? . -> . integer?) - (cond - [(list? x) (length x)] - [(string? x) (string-length x)] - [(symbol? x) (len (->string x))] - [(vector? x) (len (->list x))] - [(hash? x) (len (hash-keys x))] - [(set? x) (len (->list x))] - [else #f])) - -(module+ test - (check-equal? (len '(1 2 3)) 3) - (check-not-equal? (len '(1 2)) 3) ; len 2 - (check-equal? (len "foo") 3) - (check-not-equal? (len "fo") 3) ; len 2 - (check-equal? (len 'foo) 3) - (check-not-equal? (len 'fo) 3) ; len 2 - (check-equal? (len (list->vector '(1 2 3))) 3) - (check-not-equal? (len (list->vector '(1 2))) 3) ; len 2 - (check-equal? (len (set 1 2 3)) 3) - (check-not-equal? (len (set 1 2)) 3) ; len 2 - (check-equal? (len (make-hash '((a . 1) (b . 2) (c . 3)))) 3) - (check-not-equal? (len (make-hash '((a . 1) (b . 2)))) 3)) ; len 2 - - - -(define/contract (sliceable-container? x) - (any/c . -> . boolean?) - (ormap (λ(proc) (proc x)) (list list? string? symbol? vector?))) - -(define/contract (gettable-container? x) - (any/c . -> . boolean?) - (ormap (λ(proc) (proc x)) (list sliceable-container? hash?))) - - -;; general way of setting an item in a mutable container -(define/contract (change x i value) - ((or/c vector? hash?) any/c any/c . -> . void?) - ; general-purpose mutable data object setter - (cond - [(vector? x) (vector-set! x i value)] - [(hash? x) (hash-set! x i value)] - [else (error "Can't set this datatype using change")])) - - -;; general way of fetching an item from a container -(define/contract (get container start [end #f]) - ((gettable-container? any/c) ((λ(i)(or (integer? i) (and (symbol? i) (equal? i 'end))))) - . ->* . any/c) - - (set! end - (if (sliceable-container? container) - (cond - ;; treat negative lengths as offset from end (Python style) - [(and (integer? end) (< end 0)) (+ (len container) end)] - ;; 'end slices to the end - [(equal? end 'end) (len container)] - ;; default to slice length of 1 (i.e, single-item retrieval) - [(equal? end #f) (add1 start)] - [else end]) - end)) - - (define result (cond - ;; for sliceable containers, make a slice - [(list? container) (for/list ([i (range start end)]) - (list-ref container i))] - [(vector? container) (for/vector ([i (range start end)]) - (vector-ref container i))] - [(string? container) (substring container start end)] - [(symbol? container) (->symbol (get (->string container) start end))] - ;; for hash, just get item - [(hash? container) (hash-ref container start)] - [else #f])) - - ;; don't return single-item results inside a list - (if (and (sliceable-container? container) (= (len result) 1)) - (car (->list result)) - result)) - -(module+ test - (check-equal? (get '(0 1 2 3 4 5) 2) 2) - (check-equal? (get `(0 1 ,(list 2) 3 4 5) 2) (list 2)) - (check-equal? (get '(0 1 2 3 4 5) 0 2) '(0 1)) - (check-equal? (get '(0 1 2 3 4 5) 2 -1) '(2 3 4)) - (check-equal? (get '(0 1 2 3 4 5) 2 'end) '(2 3 4 5)) - (check-equal? (get (list->vector '(0 1 2 3 4 5)) 2) 2) - (check-equal? (get (list->vector'(0 1 2 3 4 5)) 0 2) (list->vector '(0 1))) - (check-equal? (get (list->vector'(0 1 2 3 4 5)) 2 -1) (list->vector '(2 3 4))) - (check-equal? (get (list->vector'(0 1 2 3 4 5)) 2 'end) (list->vector '(2 3 4 5))) - (check-equal? (get "purple" 2) "r") - (check-equal? (get "purple" 0 2) "pu") - (check-equal? (get "purple" 2 -1) "rpl") - (check-equal? (get "purple" 2 'end) "rple") - (check-equal? (get 'purple 2) 'r) - (check-equal? (get 'purple 0 2) 'pu) - (check-equal? (get 'purple 2 -1) 'rpl) - (check-equal? (get 'purple 2 'end) 'rple) - (check-equal? (get (make-hash `((a . ,(list 1)) (b . ,(list 2)) (c . ,(list 3)))) 'a) (list 1))) - -;; general way of testing for membership (à la Python 'in') -;; put item as first arg so function can use infix notation -;; (item . in . container) -(define/contract (in? item container) - (any/c any/c . -> . boolean?) - (->boolean (cond - [(list? container) (member item container)] ; returns #f or sublist beginning with item - [(vector? container) (vector-member item container)] ; returns #f or zero-based item index - [(hash? container) - (and (hash-has-key? container item) (get container item))] ; returns #f or hash value - [(string? container) ((->string item) . in? . (map ->string (string->list container)))] ; returns #f or substring beginning with item - [(symbol? container) ((->string item) . in? . (->string container))] ; returns #f or subsymbol (?!) beginning with item - [else #f]))) - -(module+ test - (check-true (2 . in? . '(1 2 3))) - (check-false (4 . in? . '(1 2 3))) - (check-true (2 . in? . (list->vector '(1 2 3)))) - (check-false (4 . in? . (list->vector '(1 2 3)))) - (check-true ('a . in? . (make-hash '((a . 1) (b . 2) (c . 3))))) - (check-false ('x . in? . (make-hash '((a . 1) (b . 2) (c . 3))))) - (check-true ("o" . in? . "foobar")) - (check-false ("z" . in? . "foobar")) - (check-true ('o . in? . 'foobar)) - (check-false ('z . in? . 'foobar)) - (check-false ("F" . in? . #\F))) - - -;; stringish: data type that can be trivially converted to string -;; todo: merge this with pathish -(define/contract (stringish? x) - (any/c . -> . boolean?) - (with-handlers ([exn:fail? (λ(e) #f)]) - (->boolean (->string x)))) - -;; python-style string testers -(define/contract (starts-with? str starter) - (stringish? stringish? . -> . boolean?) - (let ([str (->string str)] - [starter (->string starter)]) - (and (<= (len starter) (len str)) (equal? (get str 0 (len starter)) starter)))) - -(module+ test - (check-true ("foobar" . starts-with? . "foo")) - (check-true ("foobar" . starts-with? . "f")) - (check-true ("foobar" . starts-with? . "foobar")) - (check-false ("foobar" . starts-with? . "bar"))) - -(define/contract (ends-with? str ender) - (string? string? . -> . boolean?) - (and (<= (len ender) (len str)) (equal? (get str (- (len str) (len ender)) 'end) ender))) - -(module+ test - (check-true ("foobar" . ends-with? . "bar")) - (check-true ("foobar" . ends-with? . "r")) - (check-true ("foobar" . ends-with? . "foobar")) - (check-false ("foobar" . ends-with? . "foo"))) - -;; trim from beginning & end of list -(define (trim items test-proc) - (list? procedure? . -> . list?) - (dropf-right (dropf items test-proc) test-proc)) - -(module+ test - ; (check-equal? (trim (list "\n" " " 1 2 3 "\n") whitespace?) '(1 2 3)) - (check-equal? (trim (list 1 3 2 4 5 6 8 9 13) odd?) '(2 4 5 6 8))) - - - -;; split list into list of sublists using test-proc -(define/contract (splitf-at* xs split-test) - ;; todo: better error message when split-test is not a predicate - (list? predicate/c . -> . (listof list?)) - (define (&splitf-at* xs [acc '()]) ; use acc for tail recursion - (if (empty? xs) - ;; reverse because accumulation is happening backward - ;; (because I'm using cons to push latest match onto front of list) - (reverse acc) - (let-values ([(item rest) - ;; drop matching elements from front - ;; then split on nonmatching - ;; = nonmatching item + other elements (which will start with matching) - (splitf-at (dropf xs split-test) (compose1 not split-test))]) - ;; recurse, and store new item in accumulator - (&splitf-at* rest (cons item acc))))) - - ;; trim off elements matching split-test - (&splitf-at* (trim xs split-test))) - -(module+ test - ; (check-equal? (splitf-at* '("foo" " " "bar" "\n" "\n" "ino") whitespace?) '(("foo")("bar")("ino"))) - (check-equal? (splitf-at* '(1 2 3 4 5 6) even?) '((1)(3)(5)))) - - -;; convert a bytecount into a string -(define/contract (bytecount->string bytecount) - (integer? . -> . string?) - (define (format-with-threshold threshold suffix) - ;; upconvert by factor of 100 to get two digits after decimal - (format "~a ~a" (exact->inexact (/ (round ((* bytecount 100) . / . threshold)) 100)) suffix)) - - (define threshold-kilobyte 1000) - (define threshold-megabyte (threshold-kilobyte . * . threshold-kilobyte)) - (define threshold-gigabyte (threshold-megabyte . * . threshold-kilobyte)) - (define threshold-terabyte (threshold-gigabyte . * . threshold-kilobyte)) - - (cond - [(bytecount . >= . threshold-terabyte) (format-with-threshold threshold-terabyte "TB")] - [(bytecount . >= . threshold-gigabyte) (format-with-threshold threshold-gigabyte "GB")] - [(bytecount . >= . threshold-megabyte) (format-with-threshold threshold-megabyte "MB")] - [(bytecount . >= . threshold-kilobyte) (format-with-threshold threshold-kilobyte "KB")] - [else (format "~a bytes" bytecount)])) - - -;; for use inside quasiquote -;; instead of ,(when ...) use ,@(when/splice ...) -;; to avoid voids -(define-syntax-rule (when/splice test body) (if test (list body) '()))