Rewrite main.scm so it does not read the whole wordlist at once

main.scm

@@ -1,34 +1,40 @@
-(import (chicken io)
+(import (chicken condition)
+        (chicken io)
         (chicken process-context)
         (chicken random)
         (chicken format))
 
 (define *api-url* (get-environment-variable "MASTODON_API_URL"))
 (define *access-token* (get-environment-variable "MASTODON_ACCESS_TOKEN"))
+(define file "./words.txt")
 
-(define (file-lines file-path)
+(define (file-num-lines file-path)
   (let ((file (open-input-file file-path)))
-    (let loop ((lines '())
-               (cur (read-line file)))
-      (if (eof-object? cur)
+    (let loop ((num-lines 0))
+      (if (eof-object? (read-line file))
         (begin (close-input-port file)
-               (reverse lines))
-        (loop (cons cur lines)
-              (read-line file))))))
+               num-lines)
+        (loop (+ 1 num-lines))))))
 
-(define lines (file-lines "./words.txt"))
+(define (file-line-at file-path n)
+  (let ((file (open-input-file file-path)))
+    (let loop ((m 0)
+               (cur (read-line file)))
+      (cond
+        ((= m n)
+         (begin
+           (close-input-port file)
+           cur))
 
-(define (list-nth ls n)
-  (if (zero? n)
-    (car ls)
-    (list-nth (cdr ls) (- n 1))))
+        ((eof-object? cur)
+         (begin
+           (close-input-port file)
+           (signal (format "~s is greater than the number of lines in ~s" n file-path))))
+        
+        (else (loop (+ 1 m) (read-line file)))))))
 
-(define (list-remove-nth ls n)
-  (if (zero? n)
-    (cdr ls)
-    (cons (car ls) (list-remove-nth (cdr ls) (- n 1)))))
-
-(let ((nth (pseudo-random-integer (length lines))))
+(let* ((n (pseudo-random-integer (file-num-lines file)))
+       (line (file-line-at file n)))
   (display "Seize the means of ")
-  (display (list-nth lines nth))
+  (display line)
   (display "\n"))