(calc-convert-units): Make units a local variable.

(calc-num-units, calc-den-units): New variables.
(calc-explain-units, calc-explain-units-rec): Replace variables
num-units and den-units by declared variables.
(math-cu-unit-list): New variable.
(math-build-units-table, math-compare-unit-names)
(math-convert-units, math-convert-units-rec): Replace variable
unit-list by declared variable.
(math-fbu-base, math-fbu-entry): New variables.
(math-find-base-units, math-find-base-units-rec): Replace variables
base and entry by declared variables.
(math-which-standard): New variable.
(math-to-standard-units, math-to-standard-rec): Replace variable
which-standard by declared variable.
(math-fcu-u): New variable.
(math-find-compatible-unit, math-find-compatible-unit-rec):
Replace variable u by declared variable.
(math-cu-new-units, math-cu-pure): New variables.
(math-convert-units, math-convert-units-rec): Replace variables
new-units and pure by declared variables.
(math-try-cancel-units): New variable.
(math-simplify-units-quotient): Replace variable try-cancel-units by
declared variable.

diff --git a/lisp/calc/calc-units.el b/lisp/calc/calc-units.el
index f0c2913479938d29376060168ab389d088a1fc36..03864ce3f0798516e03bee0ae895ebfb973862b0 100644 (file)
--- a/lisp/calc/calc-units.el
+++ b/lisp/calc/calc-units.el
@@ -313,7 +313,8 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
   (calc-slow-wrapper
    (let ((expr (calc-top-n 1))
         (uoldname nil)
-        unew)
+        unew
+         units)
      (unless (math-units-in-expr-p expr t)
        (let ((uold (or old-units
                       (progn
@@ -409,20 +410,26 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
    (calc-enter-result 1 "rmun" (math-simplify-units
                                (math-extract-units (calc-top-n 1))))))
 
+;; The variables calc-num-units and calc-den-units are local to 
+;; calc-explain-units, but are used by calc-explain-units-rec,
+;; which is called by calc-explain-units.
+(defvar calc-num-units)
+(defvar calc-den-units)
+
 (defun calc-explain-units ()
   (interactive)
   (calc-wrapper
-   (let ((num-units nil)
-        (den-units nil))
+   (let ((calc-num-units nil)
+        (calc-den-units nil))
      (calc-explain-units-rec (calc-top-n 1) 1)
-     (and den-units (string-match "^[^(].* .*[^)]$" den-units)
-         (setq den-units (concat "(" den-units ")")))
-     (if num-units
-        (if den-units
-            (message "%s per %s" num-units den-units)
-          (message "%s" num-units))
-       (if den-units
-          (message "1 per %s" den-units)
+     (and calc-den-units (string-match "^[^(].* .*[^)]$" calc-den-units)
+         (setq calc-den-units (concat "(" calc-den-units ")")))
+     (if calc-num-units
+        (if calc-den-units
+            (message "%s per %s" calc-num-units calc-den-units)
+          (message "%s" calc-num-units))
+       (if calc-den-units
+          (message "1 per %s" calc-den-units)
         (message "No units in expression"))))))
 
 (defun calc-explain-units-rec (expr pow)
@@ -463,11 +470,11 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
                 (setq name (concat name "^"
                                    (math-format-number (math-abs pow))))))
          (if (math-posp pow)
-             (setq num-units (if num-units
-                                 (concat num-units " " name)
+             (setq calc-num-units (if calc-num-units
+                                 (concat calc-num-units " " name)
                                name))
-           (setq den-units (if den-units
-                               (concat den-units " " name)
+           (setq calc-den-units (if calc-den-units
+                               (concat calc-den-units " " name)
                              name))))
       (cond ((eq (car-safe expr) '*)
             (calc-explain-units-rec (nth 1 expr) pow)
@@ -615,12 +622,18 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
      (save-buffer))))
 
 
+;; The variable math-cu-unit-list is local to math-build-units-table,
+;; but is used by math-compare-unit-names, which is called (indirectly)
+;; by math-build-units-table.
+;; math-cu-unit-list is also local to math-convert-units, but is used
+;; by math-convert-units-rec, which is called by math-convert-units.
+(defvar math-cu-unit-list)
 
 (defun math-build-units-table ()
   (or math-units-table
       (let* ((combined-units (append math-additional-units
                                     math-standard-units))
-            (unit-list (mapcar 'car combined-units))
+            (math-cu-unit-list (mapcar 'car combined-units))
             tab)
        (message "Building units table...")
        (setq math-units-table-buffer-valid nil)
@@ -646,6 +659,12 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
        (message "Building units table...done")
        (setq math-units-table tab))))
 
+;; The variables math-fbu-base and math-fbu-entry are local to
+;; math-find-base-units, but are used by math-find-base-units-rec,
+;; which is called by math-find-base-units.
+(defvar math-fbu-base)
+(defvar math-fbu-entry)
+
 (defun math-find-base-units (entry)
   (if (eq (nth 4 entry) 'boom)
       (error "Circular definition involving unit %s" (car entry)))
@@ -667,7 +686,7 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
        base)))
 
 (defun math-compare-unit-names (a b)
-  (memq (car b) (cdr (memq (car a) unit-list))))
+  (memq (car b) (cdr (memq (car a) math-cu-unit-list))))
 
 (defun math-find-base-units-rec (expr pow)
   (let ((u (math-check-unit-name expr)))
@@ -751,8 +770,12 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
                           (assq (intern (substring name 3))
                                 math-units-table))))))))
 
+;; The variable math-which-standard is local to math-to-standard-units,
+;; but is used by math-to-standard-rec, which is called by
+;; math-to-standard-units.
+(defvar math-which-standard)
 
-(defun math-to-standard-units (expr which-standard)
+(defun math-to-standard-units (expr math-which-standard)
   (math-to-standard-rec expr))
 
 (defun math-to-standard-rec (expr)
@@ -763,7 +786,7 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
            (progn
              (if (nth 1 u)
                  (setq expr (math-to-standard-rec (nth 1 u)))
-               (let ((st (assq (car u) which-standard)))
+               (let ((st (assq (car u) math-which-standard)))
                  (if st
                      (setq expr (nth 1 st))
                    (setq expr (list 'var (car u)
@@ -842,9 +865,14 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
                                                unit nil))
                          t)))
 
+;; The variable math-fcu-u is local to math-find-compatible-unit,
+;; but is used by math-find-compatible-rec which is called by
+;; math-find-compatible-unit.
+(defvar math-fcu-u)
+
 (defun math-find-compatible-unit (expr unit)
-  (let ((u (math-check-unit-name unit)))
-    (if u
+  (let ((math-fcu-u (math-check-unit-name unit)))
+    (if math-fcu-u
        (math-find-compatible-unit-rec expr 1))))
 
 (defun math-find-compatible-unit-rec (expr pow)
@@ -859,39 +887,47 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
         (math-find-compatible-unit-rec (nth 1 expr) (* pow (nth 2 expr))))
        (t
         (let ((u2 (math-check-unit-name expr)))
-          (if (equal (nth 4 u) (nth 4 u2))
+          (if (equal (nth 4 math-fcu-u) (nth 4 u2))
               (cons expr pow))))))
 
-(defun math-convert-units (expr new-units &optional pure)
+;; The variables math-cu-new-units and math-cu-pure are local to 
+;; math-convert-units, but are used by math-convert-units-rec, 
+;; which is called by math-convert-units.
+(defvar math-cu-new-units)
+(defvar math-cu-pure)
+
+(defun math-convert-units (expr math-cu-new-units &optional math-cu-pure)
   (math-with-extra-prec 2
-    (let ((compat (and (not pure) (math-find-compatible-unit expr new-units)))
-         (unit-list nil)
+    (let ((compat (and (not math-cu-pure) 
+                       (math-find-compatible-unit expr math-cu-new-units)))
+         (math-cu-unit-list nil)
          (math-combining-units nil))
       (if compat
          (math-simplify-units
           (math-mul (math-mul (math-simplify-units
                                (math-div expr (math-pow (car compat)
                                                         (cdr compat))))
-                              (math-pow new-units (cdr compat)))
+                              (math-pow math-cu-new-units (cdr compat)))
                     (math-simplify-units
                      (math-to-standard-units
-                      (math-pow (math-div (car compat) new-units)
+                      (math-pow (math-div (car compat) math-cu-new-units)
                                 (cdr compat))
                       nil))))
-       (when (setq unit-list (math-decompose-units new-units))
-         (setq new-units (nth 2 (car unit-list))))
+       (when (setq math-cu-unit-list (math-decompose-units math-cu-new-units))
+         (setq math-cu-new-units (nth 2 (car math-cu-unit-list))))
        (when (eq (car-safe expr) '+)
          (setq expr (math-simplify-units expr)))
        (if (math-units-in-expr-p expr t)
            (math-convert-units-rec expr)
          (math-apply-units (math-to-standard-units
-                            (list '/ expr new-units) nil)
-                           new-units unit-list pure))))))
+                            (list '/ expr math-cu-new-units) nil)
+                           math-cu-new-units math-cu-unit-list math-cu-pure))))))
 
 (defun math-convert-units-rec (expr)
   (if (math-units-in-expr-p expr nil)
-      (math-apply-units (math-to-standard-units (list '/ expr new-units) nil)
-                       new-units unit-list pure)
+      (math-apply-units (math-to-standard-units 
+                         (list '/ expr math-cu-new-units) nil)
+                       math-cu-new-units math-cu-unit-list math-cu-pure)
     (if (Math-primp expr)
        expr
       (cons (car expr)
@@ -1026,10 +1062,12 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
                       (setcar unitp pname)
                       math-simplify-expr)))))))
 
+(defvar math-try-cancel-units)
+
 (math-defsimplify /
   (and math-simplifying-units
        (let ((np (cdr math-simplify-expr))
-            (try-cancel-units 0)
+            (math-try-cancel-units 0)
             n nn)
         (setq n (if (eq (car-safe (nth 2 math-simplify-expr)) '*)
                     (cdr (nth 2 math-simplify-expr))
@@ -1044,7 +1082,7 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
           (math-simplify-units-divisor (cdr n) (cdr (cdr math-simplify-expr)))
           (setq np (cdr (cdr n))))
         (math-simplify-units-divisor np (cdr (cdr math-simplify-expr)))
-        (if (eq try-cancel-units 0)
+        (if (eq math-try-cancel-units 0)
             (let* ((math-simplifying-units nil)
                    (base (math-simplify 
                            (math-to-standard-units math-simplify-expr nil))))
@@ -1089,8 +1127,8 @@ Entries are (SYMBOL EXPR DOC-STRING TEMP-TYPE BASE-UNITS).")
                 (setq ud1 ud)
                 (while ud1
                   (and (eq (car (car un)) (car (car ud1)))
-                       (setq try-cancel-units
-                             (+ try-cancel-units
+                       (setq math-try-cancel-units
+                             (+ math-try-cancel-units
                                 (- (* (cdr (car un)) pow1)
                                    (* (cdr (car ud)) pow2)))))
                   (setq ud1 (cdr ud1)))