Moved things around (pt 2)

1 files changed, 138 insertions, 0 deletions

@@ -0,0 +1,138 @@
+;;; Extras
+(display "EXTRAS!\n")
+(define list-append append)
+(define list-for-each for-each)
+(define list-map map)
+
+(define (map proc . collections)
+  (let ((first (car collections)))    ; we only need to check the first one
+    (cond
+     ((list? first)
+      (apply list-map proc collections))
+     ((vector? first)
+      (apply vector-map proc collections))
+     ((string? first)
+      (apply string-map proc collections))
+     (else (error "Bad datatype" first)))))
+
+(define (for-each proc . collections)
+  (let ((first (car collections)))    ; we only need to check the first one
+    (cond
+     ((list? first)
+      (apply list-for-each proc collections))
+     ((vector? first)
+      (apply vector-for-each proc collections))
+     ((string? first)
+      (apply string-for-each proc collections))
+     (else (error "Bad datatype" first)))))
+
+(define (append . collections)
+  (let ((first (car collections)))    ; we only need to check the first one
+    (cond
+     ((list? first)
+      (apply list-append collections))
+     ((vector? first)
+      (apply vector-append collections))
+     ((string? first)
+      (apply string-append collections))
+     ((bytevector? first)
+      (apply bytevector-append collections))
+     (else (error "Bad datatype" first)))))
+
+;;; Extended generic functions.
+;; These functions already have a list- version defined, but no non-prefixed
+;; one.  So I'm fixing that.
+(define (ref collection k)
+  (cond
+   ((list? collection)
+    (list-ref collection k))
+   ((vector? collection)
+    (vector-ref collection k))
+   ((string? collection)
+    (string-ref collection k))
+   ((bytevector? collection)
+    (bytevector-u8-ref collection k))
+   (else (error "Bad datatype" collection))))
+
+;; I'm not going to generalize -copy! because I don't think it's a great idea,
+;; really.
+(define (copy collection)
+  (cond
+   ((list? collection)
+    (list-copy collection))
+   ((vector? collection)
+    (vector-copy collection))
+   ((string? collection)
+    (string-copy collection))
+   ((bytevector? collection)
+    (bytevector-copy collection))
+   (else (error "Bad datatype" collection))))
+
+;;; Definitions that should be in scheme
+;; This sections should be as small as possible
+
+(define (atom? x)
+  (and (not (pair? x))
+       (not (null? x))))
+
+(define read-port-chunk-size
+  (make-parameter 512))
+
+(define (%read-port port)
+  (let ((chunk-size (read-port-chunk-size)))
+    (let loop ((next (read-string chunk-size port))
+               (blank? #f)
+               (acc '()))
+      (cond
+       ((or (eof-object? next)
+            (and blank? (equal? next "")))
+        (apply string-append (reverse acc)))
+       ((equal? next "")
+        (loop (read-string chunk-size port)
+              #t
+              (cons next acc)))
+       (else
+        (loop (read-string chunk-size port)
+              blank?
+              (cons next acc)))))))
+
+(define read-port
+  (case-lambda
+    (() (%read-port (current-input-port)))
+    ((p) (%read-port p))))
+
+(define (defined? sym)
+  (call-with-current-continuation
+   (lambda (k)
+     (with-exception-handler
+         (lambda (e) (k #f))
+       (lambda ()
+         (eval sym (interaction-environment))
+         #t)))))
+
+(define (with-output-to-string thunk)
+  (call-with-port (open-output-string)
+    (lambda (port)
+      (parameterize ((current-output-port port))
+        (thunk))
+      (get-output-string port))))
+
+(define (with-input-from-string s thunk)
+  (call-with-port (open-input-string s)
+    (lambda (port)
+      (parameterize ((current-input-port port))
+        (thunk)))))
+
+(define (displayed x)
+  (with-output-to-string
+    (lambda () (display x))))
+
+(define (written x)
+  (with-output-to-string
+    (lambda () (write x))))
+
+(define (print . xs)
+  (for-each display xs)
+  (newline))
+
+(define ->string displayed)