Make "Reverse Polish Notation" live

JRaspass · JRaspass · commit 71cad3760e77 · 2022-02-12T21:34:14.000Z
diff --git a/config/holes.toml b/config/holes.toml
@@ -1730,16 +1730,22 @@ preamble = '''
 <p>For each Roman numeral argument print the same number in Arabic numerals.
 '''
 
-['RPN Evaluator']
+['Reverse Polish Notation']
 category = 'Computing'
-experiment = -1
 links = [
     { name = 'Rosetta Code', url = '//rosettacode.org/wiki/Parsing/RPN_calculator_algorithm' },
     { name = 'Wikipedia',    url = '//www.wikipedia.org/wiki/Reverse_Polish_notation' },
 ]
 preamble = '''
-<p>Evaluate each RPN (Reverse Polish notation) expression.
-<p>The result of each operation is a non-negative integer not exceeding 32,767.
+<p>Evaluate each Reverse Polish notation expression.
+
+<p>
+    All given numbers and the result of each operation are positive integers
+    not exceeding <b>32,767</b>.
+
+<p>
+    Only the operators <code><b>+</b></code>, <code><b>-</b></code>,
+    <code><b>*</b></code>, and <code><b>/</b></code> are used.
 '''
 
 ['Rule 110']
diff --git a/db/a-schema.sql b/db/a-schema.sql
@@ -30,11 +30,12 @@ CREATE TYPE hole AS ENUM (
     'morse-encoder', 'musical-chords', 'niven-numbers', 'number-spiral',
     'odious-numbers', 'ordinal-numbers', 'pangram-grep', 'pascals-triangle',
     'pernicious-numbers', 'poker', 'prime-numbers', 'prime-numbers-long',
-    'qr-decoder', 'quine', 'recamán', 'rock-paper-scissors-spock-lizard',
-    'roman-to-arabic', 'rule-110', 'seven-segment', 'sierpiński-triangle',
-    'smith-numbers', 'spelling-numbers', 'star-wars-opening-crawl', 'sudoku',
-    'sudoku-v2', 'ten-pin-bowling', 'tongue-twisters', 'united-states',
-    'vampire-numbers', 'van-eck-sequence', 'λ', 'π', 'τ', 'φ', '√2', '𝑒'
+    'qr-decoder', 'quine', 'recamán', 'reverse-polish-notation',
+    'rock-paper-scissors-spock-lizard', 'roman-to-arabic', 'rule-110',
+    'seven-segment', 'sierpiński-triangle', 'smith-numbers',
+    'spelling-numbers', 'star-wars-opening-crawl', 'sudoku', 'sudoku-v2',
+    'ten-pin-bowling', 'tongue-twisters', 'united-states', 'vampire-numbers',
+    'van-eck-sequence', 'λ', 'π', 'τ', 'φ', '√2', '𝑒'
 );
 
 CREATE TYPE keymap AS ENUM ('default', 'vim');
diff --git a/hole/play.go b/hole/play.go
@@ -95,8 +95,8 @@ func getAnswer(holeID, code string) (args []string, answer string) {
 		answer = code
 	case "rock-paper-scissors-spock-lizard":
 		args, answer = rockPaperScissorsSpockLizard()
-	case "rpn-evaluator":
-		args, answer = rpnEvaluator()
+	case "reverse-polish-notation":
+		args, answer = reversePolishNotation()
 	case "seven-segment":
 		args, answer = sevenSegment()
 	case "spelling-numbers":
diff --git a/hole/reverse-polish-notation.go b/hole/reverse-polish-notation.go
@@ -32,8 +32,7 @@ func expand(node *Node) {
 	val := node.value
 	op := "+-*/"[rand.Intn(4)]
 
-	var leftVal int
-	var rightVal int
+	var leftVal, rightVal int
 
 	switch op {
 	case '+':
@@ -119,32 +118,32 @@ func genExpr(initVal int, expander func(*Node, int), expandCount int) *Node {
 	return init
 }
 
-func rpnEvaluator() ([]string, string) {
-	const TestsCount = 20
+func reversePolishNotation() ([]string, string) {
+	const tests = 20
 
-	exprs := [TestsCount]*Node{
+	exprs := [tests]*Node{
 		genExpr(randInt(1, MaxInt), expandLeft, randInt(16, 31)),
 		genExpr(randInt(1, MaxInt), expandRight, randInt(16, 31)),
 		genExpr(randInt(1, MaxInt), expandRight, 0),
 		genExpr(0, expandRand, randInt(16, 31)),
 	}
 
-	for i := 4; i < TestsCount; i++ {
+	for i := 4; i < tests; i++ {
 		exprs[i] = genExpr(randInt(1, MaxInt), expandRand, randInt(1, 31))
 	}
 
 	rand.Shuffle(len(exprs), func(i, j int) {
 		exprs[i], exprs[j] = exprs[j], exprs[i]
 	})
 
-	args := make([]string, TestsCount)
+	args := make([]string, tests)
 	var answer strings.Builder
 
-	for k, expr := range exprs {
+	for i, expr := range exprs {
 		var arg strings.Builder
 		printNode(&arg, expr)
-		args[k] = arg.String()
-		if k > 0 {
+		args[i] = arg.String()
+		if i > 0 {
 			answer.WriteByte('\n')
 		}
 		answer.WriteString(strconv.Itoa(expr.value))
