From acc561366f3fe6ec0377103f52ef0f7e923711c9 Mon Sep 17 00:00:00 2001
From: Rose Hogenson <rhogenson@posteo.net>
Date: Mon, 1 Aug 2022 19:35:19 -0700
Subject: Modify the project structure.

Now the lib directory contains what will eventually end up on the
user's /usr/lib/csc. When I write make install, it will copy all of
the .csc files from lib into the destination lib directory. This means I
can start working on the standard library in lib/scheme.
---
 lib/csc/vec.csc | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 lib/csc/vec.csc

(limited to 'lib/csc/vec.csc')

diff --git a/lib/csc/vec.csc b/lib/csc/vec.csc
new file mode 100644
index 0000000..2730c39
--- /dev/null
+++ b/lib/csc/vec.csc
@@ -0,0 +1,65 @@
+(define-library (csc vec)
+  (export
+    list->vec
+    vec
+    vec->list
+    vec-append
+    vec-length
+    vec-ref
+    vec?)
+  (import (scheme base))
+  (begin
+
+
+    (define-record-type <vec>
+      (make-vec len arr)
+      vec?
+      (len vec-length)
+      (arr vec-arr))
+
+
+    (define (list->vec l)
+      (let ((arr (list->vector l)))
+        (make-vec (vector-length arr) arr)))
+
+
+    (define (vec->list v)
+      (vector->list (vec-arr v) 0 (vec-length v)))
+
+
+    (define (vec . xs)
+      (list->vec xs))
+
+
+    (define (vec-ref v k)
+      (if (>= k (vec-length v))
+          (error "index out of bounds" k)
+        (vector-ref (vec-arr v) k)))
+
+
+    (define (append-one v x)
+      (let ((new-v (if (> (vector-length (vec-arr v)) (vec-length v))
+                       v
+                     (let ((new-arr (make-vector (max 1 (* 2 (vec-length v))))))
+                       (vector-copy! new-arr 0 (vec-arr v))
+                       (make-vec (vec-length v) new-arr)))))
+        (vector-set! (vec-arr new-v) (vec-length new-v) x)
+        (make-vec (+ 1 (vec-length new-v)) (vec-arr new-v))))
+
+
+    (define (append2 v1 v2)
+      (if (vec? v2)
+        (let loop ((i 0)
+                   (v v1))
+          (if (< i (vec-length v2))
+            (loop (+ 1 i) (append-one v (vec-ref v2 i)))
+            v))
+        (append-one v1 v2)))
+
+
+    (define (vec-append v . xs)
+      (let loop ((xs xs)
+                 (v v))
+        (if (null? xs)
+          v
+          (loop (cdr xs) (append2 v (car xs))))))))
-- 
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