forth: \, POSTPONE-imm split, >NUMBER, DOES> — Hayes 486→618 (97%)

lib/forth/runtime.sx

@@ -421,6 +421,40 @@
       ((forth-match-at state a1 i a2 u2 0) i)
       (else (forth-search-bytes state a1 u1 a2 u2 (+ i 1))))))
 
+(define
+  forth-digit-of-byte
+  (fn
+    (c base)
+    (let
+      ((v
+        (cond
+          ((and (>= c 48) (<= c 57)) (- c 48))
+          ((and (>= c 65) (<= c 90)) (- c 55))
+          ((and (>= c 97) (<= c 122)) (- c 87))
+          (else -1))))
+      (if (or (< v 0) (>= v base)) -1 v))))
+
+(define
+  forth-numparse-loop
+  (fn
+    (state addr u acc base)
+    (if
+      (= u 0)
+      (list acc addr u)
+      (let
+        ((c (forth-mem-read state addr)))
+        (let
+          ((dig (forth-digit-of-byte c base)))
+          (if
+            (< dig 0)
+            (list acc addr u)
+            (forth-numparse-loop
+              state
+              (+ addr 1)
+              (- u 1)
+              (+ (* acc base) dig)
+              base)))))))
+
 (define
   forth-pic-S-loop
   (fn