Refactor Guile version of day 04

1 files changed, 32 insertions, 0 deletions

diff --git a/util.scm b/util.scm
new file mode 100644
index 0000000..44a9fa8
--- /dev/null
+++ b/util.scm
@@ -0,0 +1,32 @@
+(define-module (util)
+  #:use-module (ice-9 rdelim)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-9)
+  #:use-module (srfi srfi-26)
+  #:use-module (srfi srfi-41)
+  #:export (point point? point-i point-j square array-point point-add read-map))
+
+(define-record-type <point> (point i j) point?
+                    (i point-i)
+                    (j point-j))
+
+(define (square i1 j1 i2 j2)
+  (define (row i)
+    (stream-map (cut point i <>) (stream-range j1 j2)))
+  (stream-concat (stream-map row (stream-range i1 i2))))
+
+(define (array-point arr pt)
+  (array-ref arr (point-i pt) (point-j pt)))
+
+(define (point-add pt i j)
+  (point (+ (point-i pt) i) (+ (point-j pt) j)))
+
+(define* (read-map #:optional (port (current-input-port)))
+  (define (read-lines acc)
+    (define line (read-line port))
+    (if (and (not (eof-object? line)) (> (string-length line) 0))
+        (read-lines (cons line acc))
+        acc))
+  (define strings (reverse! (read-lines '())))
+  (define string->char-codes (compose (cut map char->integer <>) string->list))
+  (list->typed-array 'u8 2 (map string->char-codes strings)))