Merge pull request JuliaLang#91 from Teo-ShaoWei/ex-phone-number

Add exercise: phone-number

config.json

@@ -283,6 +283,19 @@
         "mathematics"
       ]
     },
+    {
+      "uuid": "2e39f242-0dac-ca80-0a59-15c1850d6617a864d57",
+      "slug": "phone-number",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 1,
+      "topics": [
+        "pattern_matching",
+        "conditionals",
+        "strings",
+        "regular_expressions"
+      ]
+    },
     {
       "uuid": "e5a6d640-cd76-4453-8247-fd34ffed4fe5",
       "slug": "transpose",

exercises/phone-number/README.md

@@ -0,0 +1,36 @@
+# Phone Number
+
+Clean up user-entered phone numbers so that they can be sent SMS messages.
+
+The **North American Numbering Plan (NANP)** is a telephone numbering system used by many countries in North America like the United States, Canada or Bermuda. All NANP-countries share the same international country code: `1`.
+
+NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as *area code*, followed by a seven-digit local number. The first three digits of the local number represent the *exchange code*, followed by the unique four-digit number which is the *subscriber number*.
+
+The format is usually represented as
+
+```text
+(NXX)-NXX-XXXX
+```
+
+where `N` is any digit from 2 through 9 and `X` is any digit from 0 through 9.
+
+Your task is to clean up differently formated telephone numbers by removing punctuation and the country code (1) if present.
+
+For example, the inputs
+- `+1 (613)-995-0253`
+- `613-995-0253`
+- `1 613 995 0253`
+- `613.995.0253`
+
+should all produce the output
+
+`6139950253`
+
+**Note:** As this exercise only deals with telephone numbers used in NANP-countries, only 1 is considered a valid country code.
+## Source
+
+Event Manager by JumpstartLab [http://tutorials.jumpstartlab.com/projects/eventmanager.html](http://tutorials.jumpstartlab.com/projects/eventmanager.html)
+
+
+## Submitting Incomplete Solutions
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

exercises/phone-number/example.jl

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+function clean(phone_number)
+    # Main machinery is in the regex expression.
+    NXX = "[2-9][\\d]{2}"
+    country = "(?:\\+?1)?"
+    area = "\\(?\\s*($NXX)\\s*\\)?"
+    exchange = "($NXX)"
+    subscriber = "([\\d]{4})"
+    fillers = "\\s*(?:\\.|-)?\\s*"
+    r = Regex("^\\s*$country$fillers$area$fillers$exchange$fillers$subscriber\\s*\$")
+
+    result = match(r, phone_number)
+
+    if result != nothing
+        result = string(result.captures...)
+    end
+
+    return result
+end

exercises/phone-number/phone-number.jl

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+function clean(phone_number)
+
+end

exercises/phone-number/runtests.jl

@@ -0,0 +1,49 @@
+using Base.Test
+
+include("phone-number.jl")
+
+
+# Tests adapted from `problem-specifications//canonical-data.json` @ v1.2.0
+# Returns the cleaned phone number as a digit string if given number is valid,
+# else returns `nothing`.
+
+const expected_number = "2234567890"
+const valid_10digit_num = (
+        "(223) 456-7890",
+        "223.456.7890",
+        "223 456   7890   ",
+)
+const valid_11digit_num = (
+        "12234567890",
+        "  1 223 456 7890 ",
+        "+1 (223) 456-7890",
+)
+const invalid_num = (
+        "1223456789",
+        "22234567890",
+        "321234567890",
+        "223-abc-7890",
+        "223-@:!-7890",
+        "(023) 456-7890",
+        "(123) 456-7890",
+        "(223) 056-7890",
+        "(223) 156-7890",
+)
+
+@testset "clean 10-digit number" begin
+    @testset "$number" for number in valid_10digit_num
+        @test clean(number) == expected_number
+    end
+end
+
+@testset "clean 11-digit number starting with 1" begin
+    @testset "$number" for number in valid_11digit_num
+        @test clean(number) == expected_number
+    end
+end
+
+@testset "detect invalid number" begin
+    @testset "$number" for number in invalid_num
+        @test clean(number) == nothing
+    end
+end