From e109c255ad28591a40b994d1d38c6816443e4aa4 Mon Sep 17 00:00:00 2001
From: Peter McGoron <code@mcgoron.com>
Date: Sun, 22 Sep 2024 00:00:26 -0400
Subject: [PATCH] read: vectors

---
 read.scm | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/read.scm b/read.scm
index 004bd9e..d9ea7f7 100644
--- a/read.scm
+++ b/read.scm
@@ -139,6 +139,11 @@
                         (map:val node))))
         (action table char acc port)))))
 
+;;; Run the action in TABLE with the next character from PORT.
+(define readtable:next
+  (lambda (table acc port)
+    (readtable:act table (port 'read) acc port)))
+
 ;;; Return a new readtable where CHAR is bound to ACTION.
 (define readtable:update
   (lambda (table char action)
@@ -196,6 +201,13 @@
     (lambda (oldtable char acc port)
       (readtable:act newtable char acc port))))
 
+;;; Jump to a new readtable, reading the new character, with the old
+;;; readtable as ACC.
+(define readtable:next/old-as-acc
+  (lambda (newtable)
+    (lambda (oldtable __ _ port)
+      (readtable:next newtable oldtable port))))
+
 ;;; ;;;;;;;;;;;;;;;;;
 ;;; Identifier reader
 ;;; ;;;;;;;;;;;;;;;;;
@@ -339,7 +351,29 @@
                                readtable:read-improper-cdr)
                               port)))
 
+(define readtable:read-proper-list
+  (lambda (table port)
+    (readtable:read-list-loop (readtable:table-for-list
+                               table
+                               (readtable:error "expected proper list"))
+                              port)))
+
+;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; Reader for datum that start with "#"
+;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(define readtable:vector
+  (lambda (_ __ toplevel port)
+    (list 'vector (readtable:read-proper-list toplevel port))))
+
+(define readtable:hash
+  (readtable:process
+   (readtable:empty/default (readtable:error "unimplemented"))
+   (list readtable:update %bol readtable:vector)))
+
+;;; ;;;;;;;;;;;;;;;;
 ;;; Toplevel reader.
+;;; ;;;;;;;;;;;;;;;;
 ;;; This is defined as a function so that it dynamically loads each
 ;;; sub-readtable.
 (define readtable:top
@@ -350,6 +384,8 @@
      (list readtable:update #f (readtable:return 'eof))
      (list readtable:update %bol readtable:read-list)
      (list readtable:update %eol (readtable:error "unbalanced list"))
+     (list readtable:update #\# (readtable:next/old-as-acc
+                                 readtable:hash))
      (list readtable:update #\;
            (readtable:jump-discard readtable:read-to-newline)))))
 
@@ -387,4 +423,4 @@
 (read-all "(a   b    c     def (ghi j)  k    )")
 (read-all "(      a . b   )")
 (read-all "(   a .b . c)")
-
+(read-all "#( a b y)")