Add phone-number exercise (#88)

config.json

@@ -170,6 +170,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "phone-number",
+        "name": "Phone Number",
+        "uuid": "5a7fefe0-1f8e-4d50-8e64-a96989d0e7c8",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "rotational-cipher",
         "name": "Rotational Cipher",

exercises/practice/phone-number/.docs/instructions.append.md

@@ -0,0 +1,4 @@
+# Instructions append
+
+Overwrite the supplied phone number string.
+If the phone number is invalid, replace it with an empty string.

exercises/practice/phone-number/.docs/instructions.md

@@ -0,0 +1,34 @@
+# Instructions
+
+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.
+
+Sometimes they also have the country code (represented as `1` or `+1`) prefixed.
+
+Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code 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.

exercises/practice/phone-number/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "phone_number.s"
+    ],
+    "test": [
+      "phone_number_test.c"
+    ],
+    "example": [
+      ".meta/example.s"
+    ]
+  },
+  "blurb": "Clean up user-entered phone numbers so that they can be sent SMS messages.",
+  "source": "Exercise by the JumpstartLab team for students at The Turing School of Software and Design.",
+  "source_url": "https://turing.edu"
+}

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

@@ -0,0 +1,76 @@
+.text
+.globl clean
+
+/* extern void clean(char *str); */
+clean:
+        mov     x1, x0                  /* address for next write */
+        mov     x2, x0                  /* address for next read */
+
+.read:
+        ldrb    w3, [x2], #1            /* read byte, post-increment */
+        cbz     w3, .validate
+
+        cmp     w3, #' '
+        beq     .read
+
+        cmp     w3, #'('
+        beq     .read
+
+        cmp     w3, #')'
+        beq     .read
+
+        cmp     w3, #'+'
+        beq     .read
+
+        cmp     w3, #'-'
+        beq     .read
+
+        cmp     w3, #'.'
+        beq     .read
+
+        sub     w4, w3, #'0'
+        cmp     w4, #10
+        bhs     .reject                 /* unsigned >= */
+
+        strb    w3, [x1], #1            /* write byte, post-increment */
+        b       .read
+
+.reject:
+        strb    wzr, [x0]               /* write empty string */
+        ret
+
+.validate:
+        strb    wzr, [x1]               /* write null terminator */
+        sub     x1, x1, x0              /* number of digits */
+        cmp     x1, #11
+        beq     .eleven
+
+        cmp     x1, #10
+        bne     .reject
+
+.ten:
+        ldrb    w3, [x0]                /* first digit of exchange code */
+        sub     w4, w3, #'0'
+        cmp     w4, #2
+        blt     .reject
+
+        ldrb    w3, [x0, #3]            /* first digit of subscriber number */
+        sub     w4, w3, #'0'
+        cmp     w4, #2
+        blt     .reject
+
+        ret
+
+.eleven:
+        mov     x1, x0                  /* address for next write */
+        mov     x2, x0                  /* address for next read */
+        ldrb    w3, [x2], #1
+        cmp     w3, #'1'                /* country code */
+        bne     .reject
+
+.move:
+        ldrb    w3, [x2], #1
+        strb    w3, [x1], #1
+        cbnz    w3, .move
+
+        b       .ten

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

@@ -0,0 +1,84 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[79666dce-e0f1-46de-95a1-563802913c35]
+description = "cleans the number"
+
+[c360451f-549f-43e4-8aba-fdf6cb0bf83f]
+description = "cleans numbers with dots"
+
+[08f94c34-9a37-46a2-a123-2a8e9727395d]
+description = "cleans numbers with multiple spaces"
+
+[598d8432-0659-4019-a78b-1c6a73691d21]
+description = "invalid when 9 digits"
+include = false
+
+[2de74156-f646-42b5-8638-0ef1d8b58bc2]
+description = "invalid when 9 digits"
+reimplements = "598d8432-0659-4019-a78b-1c6a73691d21"
+
+[57061c72-07b5-431f-9766-d97da7c4399d]
+description = "invalid when 11 digits does not start with a 1"
+
+[9962cbf3-97bb-4118-ba9b-38ff49c64430]
+description = "valid when 11 digits and starting with 1"
+
+[fa724fbf-054c-4d91-95da-f65ab5b6dbca]
+description = "valid when 11 digits and starting with 1 even with punctuation"
+
+[c6a5f007-895a-4fc5-90bc-a7e70f9b5cad]
+description = "invalid when more than 11 digits"
+include = false
+
+[4a1509b7-8953-4eec-981b-c483358ff531]
+description = "invalid when more than 11 digits"
+reimplements = "c6a5f007-895a-4fc5-90bc-a7e70f9b5cad"
+
+[63f38f37-53f6-4a5f-bd86-e9b404f10a60]
+description = "invalid with letters"
+include = false
+
+[eb8a1fc0-64e5-46d3-b0c6-33184208e28a]
+description = "invalid with letters"
+reimplements = "63f38f37-53f6-4a5f-bd86-e9b404f10a60"
+
+[4bd97d90-52fd-45d3-b0db-06ab95b1244e]
+description = "invalid with punctuations"
+include = false
+
+[065f6363-8394-4759-b080-e6c8c351dd1f]
+description = "invalid with punctuations"
+reimplements = "4bd97d90-52fd-45d3-b0db-06ab95b1244e"
+
+[d77d07f8-873c-4b17-8978-5f66139bf7d7]
+description = "invalid if area code starts with 0"
+
+[c7485cfb-1e7b-4081-8e96-8cdb3b77f15e]
+description = "invalid if area code starts with 1"
+
+[4d622293-6976-413d-b8bf-dd8a94d4e2ac]
+description = "invalid if exchange code starts with 0"
+
+[4cef57b4-7d8e-43aa-8328-1e1b89001262]
+description = "invalid if exchange code starts with 1"
+
+[9925b09c-1a0d-4960-a197-5d163cbe308c]
+description = "invalid if area code starts with 0 on valid 11-digit number"
+
+[3f809d37-40f3-44b5-ad90-535838b1a816]
+description = "invalid if area code starts with 1 on valid 11-digit number"
+
+[e08e5532-d621-40d4-b0cc-96c159276b65]
+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/Makefile

@@ -0,0 +1,36 @@
+AS = aarch64-linux-gnu-as
+CC = aarch64-linux-gnu-gcc
+
+CFLAGS = -g -Wall -Wextra -pedantic -Werror
+LDFLAGS =
+
+ALL_LDFLAGS = -pie -Wl,--fatal-warnings
+
+ALL_CFLAGS = -std=c99 -fPIE $(CFLAGS)
+ALL_LDFLAGS += $(LDFLAGS)
+
+C_OBJS = $(patsubst %.c,%.o,$(wildcard *.c))
+AS_OBJS = $(patsubst %.s,%.o,$(wildcard *.s))
+ALL_OBJS = $(filter-out example.o,$(C_OBJS) $(AS_OBJS) vendor/unity.o)
+
+CC_CMD = $(CC) $(ALL_CFLAGS) -c -o $@ $<
+
+all: tests
+	qemu-aarch64 -L /usr/aarch64-linux-gnu ./$<
+
+tests: $(ALL_OBJS)
+	@$(CC) $(ALL_CFLAGS) $(ALL_LDFLAGS) -o $@ $(ALL_OBJS)
+
+%.o: %.s
+	@$(AS) -o $@ $<
+
+%.o: %.c
+	@$(CC_CMD)
+
+vendor/unity.o: vendor/unity.c vendor/unity.h vendor/unity_internals.h
+	@$(CC_CMD)
+
+clean:
+	@rm -f *.o vendor/*.o tests
+
+.PHONY: all clean

exercises/practice/phone-number/phone_number.s

@@ -0,0 +1,5 @@
+.text
+.globl clean
+
+clean:
+    ret