Implement exercise 'diamond'

config.json

@@ -340,6 +340,14 @@
         "prerequisites": [],
         "difficulty": 5
       },
+      {
+        "slug": "diamond",
+        "name": "Diamond",
+        "uuid": "b907e51b-3272-4fb7-b43c-09bcf2005fbd",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
+      },
       {
         "slug": "matching-brackets",
         "name": "Matching Brackets",

config.yaml

@@ -310,6 +310,13 @@ exercises:
     prerequisites: []
     difficulty: 5
 
+  - slug: diamond
+    name: Diamond
+    uuid: b907e51b-3272-4fb7-b43c-09bcf2005fbd
+    practices: []
+    prerequisites: []
+    difficulty: 5
+
   - slug: matching-brackets
     name: Matching Brackets
     uuid: a6c79db6-925c-45c3-8a59-aa9d96a4740b

exercises/practice/diamond/.docs/instructions.md

@@ -0,0 +1,52 @@
+# Instructions
+
+The diamond kata takes as its input a letter, and outputs it in a diamond shape.
+Given a letter, it prints a diamond starting with 'A', with the supplied letter at the widest point.
+
+## Requirements
+
+- The first row contains one 'A'.
+- The last row contains one 'A'.
+- All rows, except the first and last, have exactly two identical letters.
+- All rows have as many trailing spaces as leading spaces. (This might be 0).
+- The diamond is horizontally symmetric.
+- The diamond is vertically symmetric.
+- The diamond has a square shape (width equals height).
+- The letters form a diamond shape.
+- The top half has the letters in ascending order.
+- The bottom half has the letters in descending order.
+- The four corners (containing the spaces) are triangles.
+
+## Examples
+
+In the following examples, spaces are indicated by `·` characters.
+
+Diamond for letter 'A':
+
+```text
+A
+```
+
+Diamond for letter 'C':
+
+```text
+··A··
+·B·B·
+C···C
+·B·B·
+··A··
+```
+
+Diamond for letter 'E':
+
+```text
+····A····
+···B·B···
+··C···C··
+·D·····D·
+E·······E
+·D·····D·
+··C···C··
+···B·B···
+····A····
+```

exercises/practice/diamond/.meta/.yamlscript/exercise.mk

@@ -0,0 +1 @@
+YS_VERSION := 0.1.76

exercises/practice/diamond/.meta/Makefile

@@ -0,0 +1,28 @@
+SHELL := bash
+
+BASE := $(shell pwd)
+
+export YS_VERSION := 0.1.76
+
+YS_LOCAL_PREFIX := ../../../../.local/v$(YS_VERSION)
+
+YS_LOCAL_BIN := $(YS_LOCAL_PREFIX)/bin
+
+YS_BIN := $(YS_LOCAL_BIN)/ys-$(YS_VERSION)
+
+TEST_FILE ?= $(wildcard *-test.ys)
+
+
+export PATH := $(YS_LOCAL_BIN):$(PATH)
+
+export YSPATH := $(BASE)
+
+
+default:
+
+test: $(YS_BIN)
+	prove -v $(TEST_FILE)
+
+$(YS_BIN):
+	curl -s https://yamlscript.org/install | \
+	  BIN=1 VERSION=$(YS_VERSION) PREFIX=$(YS_LOCAL_PREFIX) bash >/dev/null

exercises/practice/diamond/.meta/config.json

@@ -0,0 +1,23 @@
+{
+  "authors": [
+    "ingydotnet"
+  ],
+  "files": {
+    "solution": [
+      "diamond.ys"
+    ],
+    "test": [
+      "diamond-test.ys",
+      "GNUmakefile",
+      "Makefile",
+      ".yamlscript/exercise.mk",
+      ".yamlscript/exercism-ys-installer"
+    ],
+    "example": [
+      ".meta/diamond.ys"
+    ]
+  },
+  "blurb": "Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.",
+  "source": "Seb Rose",
+  "source_url": "https://web.archive.org/web/20220807163751/http://claysnow.co.uk/recycling-tests-in-tdd/"
+}

exercises/practice/diamond/.meta/diamond-test.ys

@@ -0,0 +1,100 @@
+#!/usr/bin/env ys-0
+
+require ys::taptest: :all
+
+use: diamond
+
+test::
+- name: Degenerate case with a single 'a' row
+  code: rows("A")
+  want: |2
+    A
+  uuid: 202fb4cc-6a38-4883-9193-a29d5cb92076
+
+- name: Degenerate case with no row containing 3 distinct groups of spaces
+  code: rows("B")
+  want: |2
+     A 
+    B B
+     A 
+  uuid: bd6a6d78-9302-42e9-8f60-ac1461e9abae
+
+- name: Smallest non-degenerate case with odd diamond side length
+  code: rows("C")
+  want: |2
+      A  
+     B B 
+    C   C
+     B B 
+      A  
+  uuid: af8efb49 14ed-447f-8944-4cc59ce3fd76
+
+- name: Smallest non-degenerate case with even diamond side length
+  code: rows("D")
+  want: |2
+       A   
+      B B  
+     C   C 
+    D     D
+     C   C 
+      B B  
+       A   
+  uuid: e0c19a95 9888-4d05-86a0-fa81b9e70d1d
+
+- name: Largest possible diamond
+  code: rows("Z")
+  want: |2
+                             A                         
+                            B B                        
+                           C   C                       
+                          D     D                      
+                         E       E                     
+                        F         F                    
+                       G           G                   
+                      H             H                  
+                     I               I                 
+                    J                 J                
+                   K                   K               
+                  L                     L              
+                 M                       M             
+                N                         N            
+               O                           O           
+              P                             P          
+             Q                               Q         
+            R                                 R        
+           S                                   S       
+          T                                     T      
+         U                                       U     
+        V                                         V    
+       W                                           W   
+      X                                             X  
+     Y                                               Y 
+    Z                                                 Z
+     Y                                               Y 
+      X                                             X  
+       W                                           W   
+        V                                         V    
+         U                                       U     
+          T                                     T      
+           S                                   S       
+            R                                 R        
+             Q                               Q         
+              P                             P          
+               O                           O           
+                N                         N            
+                 M                       M             
+                  L                     L              
+                   K                   K               
+                    J                 J                
+                     I               I                 
+                      H             H                  
+                       G           G                   
+                        F         F                    
+                         E       E                     
+                          D     D                      
+                           C   C                       
+                            B B                        
+                             A                         
+  uuid: 82ea9aa9 4c0e-442a-b07e-40204e925944
+
+done: 5

exercises/practice/diamond/.meta/diamond.ys

@@ -0,0 +1,7 @@
+!yamlscript/v0
+
+defn rows(letter):
+  loop C letter.0, I (' ' * (((-64 + C) * 2) - 3)), O '', dmnd '':
+    line =: if(I.? "$O$C$I$C$O\n" "$O$C$O\n")
+    dmnd =: if(dmnd.? "$line$dmnd$line" line)
+    if I.?: recur(C.--, I.drop(2).join(), "$O ", dmnd), dmnd

exercises/practice/diamond/.meta/tests.toml

@@ -0,0 +1,25 @@
+# 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.
+
+[202fb4cc-6a38-4883-9193-a29d5cb92076]
+description = "Degenerate case with a single 'A' row"
+
+[bd6a6d78-9302-42e9-8f60-ac1461e9abae]
+description = "Degenerate case with no row containing 3 distinct groups of spaces"
+
+[af8efb49-14ed-447f-8944-4cc59ce3fd76]
+description = "Smallest non-degenerate case with odd diamond side length"
+
+[e0c19a95-9888-4d05-86a0-fa81b9e70d1d]
+description = "Smallest non-degenerate case with even diamond side length"
+
+[82ea9aa9-4c0e-442a-b07e-40204e925944]
+description = "Largest possible diamond"

exercises/practice/diamond/.yamlscript/exercise.mk

@@ -0,0 +1 @@
+YS_VERSION := 0.1.75