Rename approx-equal to more accurate approx=

* dev/dash-defs.el (approx-equal): Rename...
(approx=): ...to this, to more accurately reflect its function.
All references changed.

* dev/examples.el (-fixfn): Clean up examples.
* README.md:
* dash.texi: Regenerate docs.

README.md

@@ -2997,9 +2997,9 @@ cdr the final output from `halt-test`.
 In types: (a -> a) -> a -> a.
 
 ```el
-(funcall (-fixfn 'cos 'approx-equal) 0.7) ;; ~> 0.7390851332151607
+(funcall (-fixfn #'cos #'approx=) 0.7) ;; ~> 0.7390851332151607
 (funcall (-fixfn (lambda (x) (expt (+ x 10) 0.25))) 2.0) ;; => 1.8555845286409378
-(funcall (-fixfn 'sin 'approx-equal) 0.1) ;; => (halted . t)
+(funcall (-fixfn #'sin #'approx=) 0.1) ;; => (halted . t)
 ```
 
 #### -prodfn `(&rest fns)`

dash.texi

@@ -4527,7 +4527,7 @@ In types: (a -> a) -> a -> a.
 
 @example
 @group
-(funcall (-fixfn 'cos 'approx-equal) 0.7)
+(funcall (-fixfn #'cos #'approx=) 0.7)
     @result{} 0.7390851332151607
 @end group
 @group
@@ -4535,7 +4535,7 @@ In types: (a -> a) -> a -> a.
     @result{} 1.8555845286409378
 @end group
 @group
-(funcall (-fixfn 'sin 'approx-equal) 0.1)
+(funcall (-fixfn #'sin #'approx=) 0.1)
     @result{} (halted . t)
 @end group
 @end example

dev/dash-defs.el

@@ -35,14 +35,14 @@ EXPECTED should be the result of evaluating ACTUAL, and OP is one
 of the following comparison operators:
 
 -  `=>' ACTUAL should be `equal' to EXPECTED.
--  `~>' ACTUAL should be `approx-equal' to EXPECTED.
+-  `~>' ACTUAL should be `approx=' to EXPECTED.
 - `!!>' ACTUAL should signal the EXPECTED error,
         either an error symbol or an error object.")
 
 (defvar dash--epsilon 1e-15
-  "Epsilon used in `approx-equal'.")
+  "Epsilon used in `approx='.")
 
-(defun approx-equal (u v)
+(defun approx= (u v)
   "Like `=', but compares floats within `dash--epsilon'.
 This allows approximate comparison of floats to work around
 differences in implementation between systems.  Used in place of
@@ -56,7 +56,7 @@ differences in implementation between systems.  Used in place of
   "Return an ERT assertion form based on EXAMPLE."
   (pcase example
     (`(,actual => ,expected) `(should (equal ,actual ,expected)))
-    (`(,actual ~> ,expected) `(should (approx-equal ,actual ,expected)))
+    (`(,actual ~> ,expected) `(should (approx= ,actual ,expected)))
     (`(,actual !!> ,(and (pred symbolp) expected))
      ;; FIXME: Tests fail on Emacs 24-25 without `eval' for some reason.
      `(should-error (eval ',actual ,lexical-binding) :type ',expected))

dev/examples.el

@@ -21,7 +21,7 @@
 ;; so make those good.
 ;;
 ;; Use the `~>' symbol instead of `=>' to test the expected and actual
-;; values with `approx-equal'.
+;; values with `approx='.
 
 ;;; Code:
 
@@ -1710,12 +1710,14 @@ for historical reasons, and will soon be absorbed by `dash'."
                     (-last-item (-iterate fn init (1+ 5)))))) => t)
 
     (defexamples -fixfn
-      ;; Find solution to cos(x) = x (may not converge without fuzzy comparison)
+      ;; Solve cos(x) = x (may not converge without fuzzy comparison).
-      (funcall (-fixfn 'cos 'approx-equal) 0.7) ~> 0.7390851332151607
+      (funcall (-fixfn #'cos #'approx=) 0.7) ~> 0.7390851332151607
-      ;; Find solution to x^4 - x - 10 = 0 (converges using 'equal comparison)
+      ;; Solve x^4 - x - 10 = 0 (converges using `equal' comparison).
-      (funcall (-fixfn (lambda (x) (expt (+ x 10) 0.25))) 2.0) => 1.8555845286409378
+      (funcall (-fixfn (lambda (x) (expt (+ x 10) 0.25))) 2.0)
-      ;; The sin function has a fixpoint at zero, but it converges too slowly and is halted
+      => 1.8555845286409378
-      (funcall (-fixfn 'sin 'approx-equal) 0.1) => '(halted . t))
+      ;; The sin function has a fixpoint at zero, but it converges too
+      ;; slowly and is halted.
+      (funcall (-fixfn #'sin #'approx=) 0.1) => '(halted . t))
 
     (defexamples -prodfn
       (funcall (-prodfn '1+ '1- 'number-to-string) '(1 2 3)) => '(2 1 "3")