Getting the manual going

bin/pre.slime

@@ -5,26 +5,12 @@
 (define-syntax (unless condition :rest body)
   `(if ,condition nil ,(pair begin body)))
 
-;; (define-syntax defun (name arguments :rest body)
-;;   ;; (type-assert arguments :pair)
-;;   ;; `(define ,name (lambda ,arguments ,body))
-;;   ;; TODO(Felix: I think we do not need to wrap the body of the lamba
-;;   ;; in a begin
-
-;;   ;; see if we have a docstring
-;;   (if (and (= (type (first body)) :string) (not (= (type (rest body)) :nil)))
-;;       (list 'define name (list 'lambda arguments (first body) (pair 'begin (rest body))))
-;;     (list 'define name (list 'lambda arguments (pair 'begin body)))))
-
-
-;; (define-syntax defspecial (name arguments :rest body)
-;;   ;; (type-assert arguments :pair)
-;;   ;; `(define ,name (lambda ,arguments ,body))
-
-;;   ;; see if we have a docstring
-;;   (if (and (= (type (first body)) :string) (not (= (type (rest body)) :nil)))
-;;       (list 'define name (list 'special-lambda arguments (first body) (pair 'begin (rest body))))
-;;     (list 'define name (list 'special-lambda arguments (pair 'begin body)))))
+(define-syntax (n-times times action)
+  "Executes action times times."
+  (define (repeat times elem)
+    (unless (> 1 times)
+      (pair elem (repeat (- times 1) elem))))
+  (pair 'begin (repeat times action)))
 
 ;; (define (fib n))
 ;; (define-syntax define (name :rest value)
@@ -41,7 +27,6 @@
 ;;      (print "\nbb\n")
 ;;      (pair 'define (pair name value)))))
 
-;; TODO(Felix): else symbol
 (define-syntax (cond :rest clauses)
   (define (rec clauses)
     (if (= nil clauses)
@@ -122,13 +107,6 @@ the (rest) of the last element of the sequence."
 with (pair elem nil)."
   (extend seq (pair elem nil)))
 
-(define-syntax (extend! seq elem)
-  "test"
-  `(mutate ,seq (extend ,seq ,elem)))
-
-(define-syntax (append! seq elem)
-  `(mutate ,seq (append ,seq ,elem)))
-
 (define (length seq)
   "Returns the length of the given sequence."
   (if (nil? seq)
@@ -143,11 +121,6 @@ with (pair elem nil)."
   "Subtracts one from the argument."
   (- val 1))
 
-;; (defmacro n-times (@times @action)
-;;   "Executes @action @times times."
-;;   (unless (<= (eval @times) 0)
-;;     (eval @action)
-;;     (apply n-times (list (list - @times 1) @action))))
 
 ;; (defmacro for (@symbol @from @to :rest @for-body)
 ;;   "Designed to resemble a C style for loop. It takes a symbol as
@@ -226,6 +199,14 @@ added to a list, which in the end is returned."
       nil
     (pair (list (first l1) (first l2)) (zip (rest l1) (rest l2)))))
 
+(define (enumerate seq)
+  (define (enumerate-inner seq next-num)
+    (when seq
+      (pair (list (first seq) next-num)
+            (enumerate-inner (rest seq) (+ 1 next-num)))))
+  (enumerate-inner seq 0))
+
+
 (define (printf :keys sep :defaults-to " " end :defaults-to "\n" :rest args)
   "A wrapper for the built-in (print) that accepts a variable number
 of arguments and also provides keywords for specifying the printed
@@ -244,4 +225,4 @@ las argument."
   (eval (pair printf-quoted (extend (list :@sep (eval sep) :@end (eval end)) args))))
 
 (define-syntax (pe expr)
-  `(printf ',expr "evaluates to" ,(eval expr)))
+  `(printf ',expr "evaluates to" ,expr))