Implemented all "Phone Number" problems from the canonical test data. (#465)

config.json

@@ -287,19 +287,6 @@
           "number_theory"
         ]
       },
-      {
-        "slug": "phone-number",
-        "name": "Phone Number",
-        "uuid": "c211045e-da97-479d-9df4-5d812573e2d0",
-        "practices": [],
-        "prerequisites": [],
-        "difficulty": 2,
-        "topics": [
-          "interfaces",
-          "parsing",
-          "strings"
-        ]
-      },
       {
         "slug": "queen-attack",
         "name": "Queen Attack",
@@ -942,6 +929,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 2
+      },
+      {
+        "slug": "phone-number",
+        "name": "Phone Number",
+        "uuid": "c211045e-da97-479d-9df4-5d812573e2d0",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
       }
     ]
   },

exercises/practice/phone-number/.meta/example.el

@@ -2,32 +2,81 @@
 
 ;;; Commentary:
 
-;;; Code:
+(defun char-digit-p (x)
+  (<= ?0 x ?9))
 
+(defun char-lowercase-p (x)
+  (<= ?a x ?z))
 
-(defun numbers (num)
-  (let ((number (replace-regexp-in-string "[^0-9]+" "" num)))
-    (cond
-     ((= (length number) 10) number)
-     ((and (= (length number) 11)
-           (string-equal (substring number 0 1) "1")) (substring number 1))
-     (t "0000000000"))))
-
-
-(defun area-code (num)
-  (substring (numbers num) 0 3))
+(defun char-uppercase-p (x)
+  (<= ?A x ?Z))
 
+(defun char-alphabetic-p (x)
+  (or (char-lowercase-p x)
+      (char-uppercase-p x)))
 
-(defun prefix (num)
-  (substring (numbers num) 3 6))
+(defun char-punctuation-p (x)
+  (or (<= 33 x 39)
+      (= x 42)
+      (= x 44)
+      (= x 47)
+      (<= 58 x 64)
+      (<= 91 x 96)
+      (<= 123 x 126)))
 
+(defun negate (pred)
+  (lambda (&rest args) (apply pred args)))
 
-(defun line-number (num)
-  (substring (numbers num) 6))
+(defun string-remove (s pred)
+  (let* ((n (length s))
+         (to-str (make-string n ?\0))
+         (k 0))
+    (dotimes (i n)
+      (let ((x (aref s i)))
+        (when (funcall pred x)
+          (setf (aref to-str k) x)
+          (cl-incf k))))
+    (substring to-str 0 k)))
 
+(defun numbers (num)
+  "Converts a num string into a string of digits."
+  (cond
+   ((cl-find-if #'char-alphabetic-p num)
+    (error "letters not permitted"))
+   ((cl-find-if #'char-punctuation-p num)
+    (error "punctuations not permitted")))
+  (let* ((digits (string-remove num (negate #'char-digit-p)))
+         (n (length digits)))
+    (cond
+     ((< n 10) (error "must not be fewer than 10 digits"))
+     ((> n 11) (error "must not be greater than 11 digits")))
+    (if (= n 11)
+        (if (= (aref digits 0) ?1)
+            (setf digits (substring digits 1))
+          (error "11 digits must start with 1")))
+    (let ((y (aref digits 0)))
+      (cond
+       ((= y ?0)
+        (error "area code cannot start with zero"))
+       ((= y ?1)
+        (error "area code cannot start with one"))))
+    (let ((y (aref digits 3)))
+      (cond
+       ((= y ?0)
+        (error "exchange code cannot start with zero"))
+       ((= y ?1)
+        (error "exchange code cannot start with one"))))
+    digits))
+
+(defun area-code (num)
+  (let ((digits (numbers num)))
+    (substring digits 0 3)))
 
 (defun pprint (num)
-  (format "(%s) %s-%s" (area-code num) (prefix num) (line-number num)))
+  (let ((digits (numbers num)))
+    (format "(%s) %s-%s" (substring digits 0 3)
+            (substring digits 3 6)
+            (substring digits 6 10))))
 
 
 (provide 'phone-number)

exercises/practice/phone-number/.meta/tests.toml

@@ -82,3 +82,4 @@ description = "invalid if exchange code starts with 0 on valid 11-digit number"
 
 [57b32f3d-696a-455c-8bf1-137b6d171cdf]
 description = "invalid if exchange code starts with 1 on valid 11-digit number"
+

exercises/practice/phone-number/phone-number-test.el

@@ -1,4 +1,4 @@
-;;; phone-number-test.el --- Tests for phone-number (exercism)  -*- lexical-binding: t; -*-
+;;; phone-number-test.el --- Phone Number (exercism)  -*- lexical-binding: t; -*-
 
 ;;; Commentary:
 
@@ -9,35 +9,72 @@
 (declare-function area-code "phone-number.el" (num))
 (declare-function pprint "phone-number.el" (num))
 
-(ert-deftest cleans-number-test ()
-  (should (equal (numbers "(223) 456-7890") "2234567890")))
+(ert-deftest cleans-the-number ()
+  (should (string= (numbers "(223) 456-7890") "2234567890")))
 
+(ert-deftest cleans-numbers-with-dots ()
+  (should (string= (numbers "223.456.7890") "2234567890")))
 
-(ert-deftest cleans-numbers-with-dots-test ()
-  (should (equal (numbers "223.456.7890") "2234567890")))
+(ert-deftest cleans-numbers-with-multiple-spaces ()
+  (should (string= (numbers "223 456   7890   ") "2234567890")))
 
+(ert-deftest invalid-when-9-digits ()
+  (should (string= (cadr (should-error (numbers "123456789")))
+                   "must not be fewer than 10 digits")))
 
-(ert-deftest valid-when-11-digits-and-first-is-1-test ()
-  (should (equal (numbers "12234567890") "2234567890")))
+(ert-deftest invalid-when-11-digits-does-not-start-with-a-1 ()
+  (should (string= (cadr (should-error (numbers "22234567890")))
+                   "11 digits must start with 1")))
 
+(ert-deftest valid-when-11-digits-and-starting-with-1 ()
+  (should (string= (numbers "12234567890") "2234567890")))
 
-(ert-deftest invalid-when-11-digits-test ()
-  (should (equal (numbers "21234567890") "0000000000")))
+(ert-deftest valid-when-11-digits-and-starting-with-1-even-with-punctuation ()
+  (should (string= (numbers "+1 (223) 456-7890") "2234567890")))
 
+(ert-deftest invalid-when-more-than-11-digits ()
+  (should (string= (cadr (should-error (numbers "321234567890")))
+                   "must not be greater than 11 digits")))
 
-(ert-deftest invalid-when-9-digits-test ()
-  (should (equal (numbers "123456789") "0000000000")))
+(ert-deftest invalid-with-letters ()
+  (should (string= (cadr (should-error (numbers "523-abc-7890")))
+                   "letters not permitted")))
 
-(ert-deftest invalid-when-more-than-11-digits-test ()
-  (should (equal (numbers "321234567890") "0000000000")))
+(ert-deftest invalid-with-punctuations ()
+  (should (string= (cadr (should-error (numbers "523-@:!-7890")))
+                   "punctuations not permitted")))
 
-(ert-deftest invalid-with-letters ()
-  (should (equal (numbers "523-abc-7890") "0000000000")))
+(ert-deftest invalid-if-area-code-starts-with-0 ()
+  (should (string= (cadr (should-error (numbers "(023) 456-7890")))
+                   "area code cannot start with zero")))
 
+(ert-deftest invalid-if-area-code-starts-with-1 ()
+  (should (string= (cadr (should-error (numbers "(123) 456-7890")))
+                   "area code cannot start with one")))
 
-(ert-deftest invalid-with-punctuations ()
-  (should (equal (numbers "523-@:!-7890") "0000000000")))
+(ert-deftest invalid-if-exchange-code-starts-with-0 ()
+  (should (string= (cadr (should-error (numbers "(223) 056-7890")))
+                   "exchange code cannot start with zero")))
+
+(ert-deftest invalid-if-exchange-code-starts-with-1 ()
+  (should (string= (cadr (should-error (numbers "(223) 156-7890")))
+                   "exchange code cannot start with one")))
 
+(ert-deftest invalid-if-area-code-starts-with-0-on-valid-11-digit-number ()
+  (should (string= (cadr (should-error (numbers "1 (023) 456-7890")))
+                   "area code cannot start with zero")))
+
+(ert-deftest invalid-if-area-code-starts-with-1-on-valid-11-digit-number ()
+  (should (string= (cadr (should-error (numbers "1 (123) 456-7890")))
+                   "area code cannot start with one")))
+
+(ert-deftest invalid-if-exchange-code-starts-with-0-on-valid-11-digit-number ()
+  (should (string= (cadr (should-error (numbers "1 (223) 056-7890")))
+                   "exchange code cannot start with zero")))
+
+(ert-deftest invalid-if-exchange-code-starts-with-1-on-valid-11-digit-number ()
+  (should (string= (cadr (should-error (numbers "1 (223) 156-7890")))
+                   "exchange code cannot start with one")))
 
 (ert-deftest area-code-test ()
   (should (equal (area-code "2234567890") "223")))
@@ -50,6 +87,6 @@
 (ert-deftest pprint-full-us-phone-number-test ()
   (should (equal (pprint "12234567890") "(223) 456-7890")))
 
-
-(provide 'phone-number)
+(provide 'phone-number-test)
 ;;; phone-number-test.el ends here
+

exercises/practice/phone-number/phone-number.el

@@ -1,4 +1,4 @@
-;;; phone-number.el --- phone-number Exercise (exercism)  -*- lexical-binding: t; -*-
+;;; phone-number.el --- phone-number (exercism)  -*- lexical-binding: t; -*-
 
 ;;; Commentary: