Correct capital example in README

README.md

@@ -2,20 +2,27 @@
 
 This package was adapted from [romannumeral](https://github.com/brandenc40/romannumeral) to fit my specific minimal use-case.
 
-All functionality except for the ability to convert integers to **lowercase** roman numerals has been removed.
+All functionality except for the ability to convert integers to roman numerals has been removed.
+
+Since I have less functionality to worry about, I was also able to implement vinculum notation support to extend the range of supported integers to 3,999,999.
+I also added the ability to choose between uppercase and lowercase roman numerals (optimized for lowercase due to my personal use-case).
 
 If you need any additional functionality or further documentation, please see the original package.
 
 ### Benchmark Results
 
+Note that the benchmark results of this fork are slower than upstream due to the added vinculum notation support.
+This benchmark tests the highest supported integer (3,999,999) while upstream tests with 3,999.
+
 ```sh
 goos: linux
 goarch: amd64
 pkg: github.com/rwinkhart/convertroman
 cpu: AMD Ryzen 9 3900X 12-Core Processor
-BenchmarkFromInt-24    	61993154	        20.82 ns/op	       0 B/op	       0 allocs/op
+BenchmarkFromInt-24           	 5372720	       237.0 ns/op	      24 B/op	       1 allocs/op
+BenchmarkFromIntCapital-24    	 2117424	       570.9 ns/op	      64 B/op	       3 allocs/op
 PASS
-ok  	github.com/rwinkhart/convertroman	1.827s
+ok  	github.com/rwinkhart/convertroman	4.098s
 ```
 
 ### Example
@@ -28,11 +35,22 @@ import (
 	rom "github.com/rwinkhart/convertroman"
 )
 
-func ExampleFromInt() {
+func main() {
-	roman := FromInt(4)
+	var roman string
+
+	// lowercase
+	roman = rom.FromInt(4)
 	if roman == "OOB" {
-		panic("Input integer is out of bounds")
+		panic("Input integer is out of bounds (greater than 3,999,999)")
 	}
-	fmt.Println(roman == "IV") // True
+	fmt.Println(roman == "iv") // True
+
+	// capital (slightly slower)
+	// this example uses a number in vinculum notation to show that ANSI escape codes are used to provide the overline
+	roman = rom.FromIntCapital(4065)
+	if roman == "OOB" {
+		panic("Input integer is out of bounds (greater than 3,999,999)")
+	}
+	fmt.Println(roman == "\033[53mIV\033[0mLXV") // True
 }
 ```

convertroman.go

@@ -1,8 +1,6 @@
 package convertroman
 
-// Currently only supports Roman Numerals without viniculum (1-3999; "OOB" is returned for values outside this range)
+import "strings"
-// See here for details on viniculum:
-// https://en.wikipedia.org/wiki/Roman_numerals#Large_numbers
 
 var (
 	// lookup arrays used for converting from an int to a roman numeral extremely quickly.
@@ -14,13 +12,48 @@ var (
 )
 
 // FromInt converts an integer value to a roman numeral string.
-// "OOB" is returned if the integer is not between 1 and 3999.
+// The function will return "0" if the input integer is less than 1.
+// The function will return "OOB" if the input integer is greater than
+// or equal to 4,000,000 (the roman numeral vinculum limit).
 func FromInt(input int) string {
-	// ensure provided integer is within the valid range
+	if input < 1 {
-	if input < 1 || input > 3999 {
+		return "0"
+	} else if input < 4000 {
+		return baseRange(input)
+	} else if input < 4000000 {
+		thousands, remainder := separateThousands(input)
+		return vinculumRange(thousands) + baseRange(remainder)
+	} else {
 		return "OOB"
 	}
+}
 
-	// convert the integer to a roman numeral string and return it
+// FromIntCapital very inefficiently converts an integer value to a CAPITAL roman numeral string.
+// Note that this package is optimized for lowercase roman numerals. As such, this function is a slow afterthought.
+func FromIntCapital(input int) string {
+	if input < 4000 {
+		// if below vinculum range, return the translated result
+		return strings.ToUpper(FromInt(input))
+	} else {
+		// if in vinculum range, remove the ANSI escape codes, capitalize the result, and reapply the ANSI escape codes
+		noPrefix := strings.TrimPrefix(FromInt(input), "\033[53m")
+		secondIndex := strings.Index(noPrefix, "\033[0m")
+		capitalPreANSI := strings.ToUpper(noPrefix[:secondIndex] + noPrefix[secondIndex+4:])
+		return "\033[53m" + capitalPreANSI[:secondIndex] + "\033[0m" + capitalPreANSI[secondIndex:]
+	}
+}
+
+// separateThousands separates an integer into two parts: the thousands and the remainder.
+func separateThousands(num int) (int, int) {
+	return num / 1000, num % 1000
+}
+
+// vinculumRange returns a roman numeral string for an integer greater than 3999.
+func vinculumRange(input int) string {
+	return "\033[53m" + baseRange(input) + "\033[0m"
+}
+
+// baseRange returns a roman numeral string for an integer between 1 and 3999.
+func baseRange(input int) string {
 	return r3[input%1e4/1e3] + r2[input%1e3/1e2] + r1[input%100/10] + r0[input%10]
 }

convertroman_test.go

@@ -1,7 +1,6 @@
 package convertroman
 
 import (
-	"fmt"
 	"testing"
 )
 
@@ -22,6 +21,22 @@ var testCases = map[string]int{
 	"dcccxlix": 849, "cmiv": 904, "m": 1000, "mvii": 1007, "mlxvi": 1066,
 	"mccxxxiv": 1234, "mdcclxxvi": 1776, "mmxxi": 2021, "mmdcccvi": 2806,
 	"mmcmxcix": 2999, "mmm": 3000, "mmmcmlxxix": 3979, "mmmcmxcix": 3999,
+	"\033[53miv\033[0m": 4000, "\033[53mv\033[0m": 5000, "\033[53mvi\033[0m": 6000,
+	"\033[53mvii\033[0m": 7000, "\033[53mviii\033[0m": 8000, "\033[53mix\033[0m": 9000, "\033[53mx\033[0m": 10000, "\033[53mxi\033[0m": 11000, "\033[53mxii\033[0m": 12000,
+	"\033[53mxiii\033[0m": 13000, "\033[53mxiv\033[0m": 14000, "\033[53mxv\033[0mxcix": 15099, "\033[53mxvi\033[0m": 16000, "\033[53mxvii\033[0m": 17000,
+	"\033[53mxviii\033[0mi": 18001, "\033[53mxix\033[0m": 19000, "\033[53mxx\033[0m": 20000, "\033[53mxxxi\033[0m": 31000, "\033[53mxxxii\033[0m": 32000,
+	"\033[53mxxxiii\033[0m": 33000, "\033[53mxxxiv\033[0m": 34000, "\033[53mxxxv\033[0m": 35000, "\033[53mxxxvi\033[0m": 36000, "\033[53mxxxvii\033[0m": 37000,
+	"\033[53mxxxviii\033[0m": 38000, "\033[53mxxxix\033[0m": 39000, "\033[53mxl\033[0m": 40000, "\033[53mxli\033[0m": 41000, "\033[53mxlii\033[0m": 42000,
+	"\033[53mxliii\033[0m": 43000, "\033[53mxliv\033[0m": 44000, "\033[53mxlv\033[0mlvi": 45056, "\033[53mxlvi\033[0m": 46000, "\033[53mxlvii\033[0m": 47000,
+	"\033[53mxlviii\033[0m": 48000, "\033[53mxlix\033[0m": 49000, "\033[53ml\033[0m": 50000, "\033[53mlxxxix\033[0mc": 89100, "\033[53mxc\033[0m": 90000,
+	"\033[53mxci\033[0m": 91000, "\033[53mxcii\033[0m": 92000, "\033[53mxciii\033[0m": 93000, "\033[53mxciv\033[0m": 94000, "\033[53mxcv\033[0m": 95000,
+	"\033[53mxcvi\033[0m": 96000, "\033[53mxcvii\033[0m": 97000, "\033[53mxcviii\033[0m": 98000, "\033[53mxcix\033[0m": 99000, "\033[53mc\033[0m": 100000,
+	"\033[53mci\033[0m": 101000, "\033[53mcii\033[0mcxxvii": 102127, "\033[53mciii\033[0m": 103000, "\033[53mciv\033[0m": 104000, "\033[53mcv\033[0m": 105000,
+	"\033[53mcvi\033[0m": 106000, "\033[53mcvii\033[0m": 107000, "\033[53mcviii\033[0m": 108000, "\033[53mcix\033[0m": 109000, "\033[53mcxlix\033[0m": 149000,
+	"\033[53mcccxlix\033[0m": 349000, "\033[53mcdlvi\033[0m": 456000, "\033[53md\033[0m": 500000, "\033[53mdciv\033[0m": 604000, "\033[53mdcclxxxix\033[0m": 789000,
+	"\033[53mdcccxlix\033[0m": 849000, "\033[53mcmiv\033[0m": 904000, "\033[53mm\033[0m": 1000000, "\033[53mmvii\033[0m": 1007000, "\033[53mmlxvi\033[0m": 1066000,
+	"\033[53mmccxxxiv\033[0m": 1234000, "\033[53mmdcclxxvi\033[0m": 1776000, "\033[53mmmxxi\033[0m": 2021000, "\033[53mmmdcccvi\033[0mcdxlii": 2806442,
+	"\033[53mmmcmxcix\033[0m": 2999000, "\033[53mmmm\033[0m": 3000000, "\033[53mmmmcmlxxix\033[0m": 3979000, "\033[53mmmmcmxcix\033[0m": 3999000,
 }
 
 func TestFromInt(t *testing.T) {
@@ -33,27 +48,26 @@ func TestFromInt(t *testing.T) {
 			t.Errorf("FromInt(%d) = %s; want %s", input, out, expected)
 		}
 	}
-	out := FromInt(100000)
+	out := FromInt(4000000)
 	if out != "OOB" {
-		t.Errorf("FromInt(%d) expected an error", 100000)
+		t.Errorf("FromInt(%d) expected an error", 4000000)
 	}
 	out = FromInt(0)
-	if out != "OOB" {
+	if out != "0" {
-		t.Errorf("FromInt(%d) expected an error", 0)
+		t.Errorf("FromInt(%d) something went wrong (0 should resolve to 0)", 0)
 	}
 }
 
 func BenchmarkFromInt(b *testing.B) {
 	b.ReportAllocs()
 	for i := 0; i < b.N; i++ {
-		_ = FromInt(3999)
+		_ = FromInt(3999999)
 	}
 }
 
-func ExampleFromInt() {
+func BenchmarkFromIntCapital(b *testing.B) {
-	roman := FromInt(4)
+	b.ReportAllocs()
-	if roman == "OOB" {
+	for i := 0; i < b.N; i++ {
-		panic("Input integer is out of bounds")
+		_ = FromIntCapital(3999999)
 	}
-	fmt.Println(roman == "IV") // True
 }

go.mod

@@ -1,3 +1,3 @@
 module github.com/rwinkhart/convertroman
 
-go 1.15
+go 1.23