ocaml: phase 1/5/6 float arithmetic +./-./*./. (+5 tests, 372 total)

Tokenizer: +. -. *. /. (with -. avoiding clash with negative float
literals). Parser table places dotted ops at int-precedence levels.
Eval routes to host SX +/-/*//. HM types them Float->Float->Float;
literal floats now infer as Float (was Int).

OCaml-style 1.5 +. 2.5 : Float works end-to-end through tokenize +
parse + eval + infer.

lib/ocaml/eval.sx

@@ -328,6 +328,10 @@
       ((= op "-")    (- lhs rhs))
       ((= op "*")    (* lhs rhs))
       ((= op "/")    (/ lhs rhs))
+      ((= op "+.")   (+ lhs rhs))
+      ((= op "-.")   (- lhs rhs))
+      ((= op "*.")   (* lhs rhs))
+      ((= op "/.")   (/ lhs rhs))
       ((= op "mod")  (mod lhs rhs))
       ((= op "%")    (mod lhs rhs))
       ((= op "**")   (pow lhs rhs))

lib/ocaml/infer.sx

@@ -37,9 +37,15 @@
          "true" (hm-monotype (hm-bool))
          "false" (hm-monotype (hm-bool))}))))
 
+;; Float type isn't in the kit; use a named ctor.
+(define ocaml-hm-float (fn () (hm-con "Float" (list))))
+
 (define ocaml-hm-builtin-env
   (fn ()
     (let ((int-int-int (hm-arrow (hm-int) (hm-arrow (hm-int) (hm-int))))
+          (float-float-float
+            (hm-arrow (ocaml-hm-float)
+              (hm-arrow (ocaml-hm-float) (ocaml-hm-float))))
           (int-int-bool (hm-arrow (hm-int) (hm-arrow (hm-int) (hm-bool))))
           (bool-bool-bool (hm-arrow (hm-bool) (hm-arrow (hm-bool) (hm-bool))))
           (str-str-str (hm-arrow (hm-string) (hm-arrow (hm-string) (hm-string))))
@@ -66,6 +72,10 @@
        "-"  (hm-monotype int-int-int)
        "*"  (hm-monotype int-int-int)
        "/"  (hm-monotype int-int-int)
+       "+." (hm-monotype float-float-float)
+       "-." (hm-monotype float-float-float)
+       "*." (hm-monotype float-float-float)
+       "/." (hm-monotype float-float-float)
        "mod" (hm-monotype int-int-int)
        "%"  (hm-monotype int-int-int)
        "**" (hm-monotype int-int-int)
@@ -444,7 +454,7 @@
               (else
                 {:subst {} :type (hm-fresh-tv counter)}))))
         ((= tag "int")    {:subst {} :type (hm-int)})
-        ((= tag "float")  {:subst {} :type (hm-int)})  ;; treat float as int for now
+        ((= tag "float")  {:subst {} :type (ocaml-hm-float)})
         ((= tag "string") {:subst {} :type (hm-string)})
         ((= tag "char")   {:subst {} :type (hm-string)})
         ((= tag "bool")   {:subst {} :type (hm-bool)})
@@ -572,5 +582,6 @@
               (let ((a (ocaml-hm-format-type (nth args 0)))
                     (b (ocaml-hm-format-type (nth args 1))))
                 (str "(" a ", " b ") result")))
+            ((= head "Float") "Float")
             (else head))))
       (else (str t)))))

lib/ocaml/parser.sx

@@ -67,8 +67,12 @@
     (list "::" 6 :right)
     (list "+" 7 :left)
     (list "-" 7 :left)
+    (list "+." 7 :left)
+    (list "-." 7 :left)
     (list "*" 8 :left)
     (list "/" 8 :left)
+    (list "*." 8 :left)
+    (list "/." 8 :left)
     (list "%" 8 :left)
     (list "mod" 8 :left)
     (list "land" 8 :left)

lib/ocaml/test.sh

@@ -910,6 +910,18 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 2203)
 (eval "(ocaml-run \"List.map2 (fun a b -> a + b) [1;2;3] [10;20;30]\")")
 
+;; ── Float arithmetic ───────────────────────────────────────────
+(epoch 2300)
+(eval "(ocaml-run \"1.5 +. 2.5\")")
+(epoch 2301)
+(eval "(ocaml-run \"3.0 *. 2.0\")")
+(epoch 2302)
+(eval "(ocaml-run \"10.0 /. 4.0\")")
+(epoch 2303)
+(eval "(ocaml-type-of \"1.5 +. 2.5\")")
+(epoch 2304)
+(eval "(ocaml-type-of \"fun x y -> x +. y\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 180 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -1439,6 +1451,13 @@ check 2201 "List.split"                   '("tuple" (1 2) ("a" "b"))'
 check 2202 "List.fold_left2"              '66'
 check 2203 "List.map2"                    '(11 22 33)'
 
+# ── Float arithmetic ────────────────────────────────────────────
+check 2300 "1.5 +. 2.5"                   '4'
+check 2301 "3.0 *. 2.0"                   '6'
+check 2302 "10.0 /. 4.0"                  '2.5'
+check 2303 "type 1.5 +. 2.5"              '"Float"'
+check 2304 "type fun x y -> x +. y"       '"Float -> Float -> Float"'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL OCaml-on-SX tests passed"

lib/ocaml/tokenizer.sx

@@ -294,6 +294,14 @@
             (cond
               ((and (= c ";") (= c1 ";"))
                 (begin (advance! 2) (push! "op" ";;" start) true))
+              ((and (= c "+") (= c1 "."))
+                (begin (advance! 2) (push! "op" "+." start) true))
+              ((and (= c "-") (= c1 ".") (not (and (not (= c2 nil)) (ocaml-digit? c2))))
+                (begin (advance! 2) (push! "op" "-." start) true))
+              ((and (= c "*") (= c1 "."))
+                (begin (advance! 2) (push! "op" "*." start) true))
+              ((and (= c "/") (= c1 "."))
+                (begin (advance! 2) (push! "op" "/." start) true))
               ((and (= c "-") (= c1 ">"))
                 (begin (advance! 2) (push! "op" "->" start) true))
               ((and (= c "<") (= c1 "-"))