From 6fab6530048ce8268098c5ef39c193028c5947ec Mon Sep 17 00:00:00 2001
From: Nathan Baulch <nathan.baulch@gmail.com>
Date: Sun, 16 Aug 2020 23:02:43 +1000
Subject: [PATCH] Remove problematic numbers regexp

---
 camel.go      |  6 ++++--
 numbers.go    | 38 --------------------------------------
 snake.go      |  7 ++++---
 snake_test.go |  6 ++++++
 4 files changed, 14 insertions(+), 43 deletions(-)
 delete mode 100644 numbers.go

diff --git a/camel.go b/camel.go
index ab2d261..f31646e 100644
--- a/camel.go
+++ b/camel.go
@@ -38,7 +38,6 @@ func toCamelInitCase(s string, initCase bool) string {
 		s = a
 	}
 
-	s = addWordBoundariesToNumbers(s)
 	n := strings.Builder{}
 	n.Grow(len(s))
 	capNext := initCase
@@ -56,9 +55,12 @@ func toCamelInitCase(s string, initCase bool) string {
 				v -= 'A'
 			}
 		}
-		if vIsCap || vIsLow || (v >= '0' && v <= '9') {
+		if vIsCap || vIsLow {
 			n.WriteByte(v)
 			capNext = false
+		} else if vIsNum := v >= '0' && v <= '9'; vIsNum {
+			n.WriteByte(v)
+			capNext = true
 		} else {
 			capNext = v == '_' || v == ' ' || v == '-' || v == '.'
 		}
diff --git a/numbers.go b/numbers.go
deleted file mode 100644
index fdf07cb..0000000
--- a/numbers.go
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2015 Ian Coleman
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, Subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or Substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package strcase
-
-import (
-	"regexp"
-)
-
-var numberSequence = regexp.MustCompile(`([a-zA-Z])(\d+)([a-zA-Z]?)`)
-var numberReplacement = []byte(`$1 $2 $3`)
-
-func addWordBoundariesToNumbers(s string) string {
-	b := []byte(s)
-	b = numberSequence.ReplaceAll(b, numberReplacement)
-	return string(b)
-}
diff --git a/snake.go b/snake.go
index fa1f8f4..b849a58 100644
--- a/snake.go
+++ b/snake.go
@@ -64,7 +64,6 @@ func ToDelimited(s string, delimiter uint8) string {
 // or delimited.snake.case
 // (in this case `delimiter = '.'; screaming = false`)
 func ToScreamingDelimited(s string, delimiter uint8, ignore uint8, screaming bool) string {
-	s = addWordBoundariesToNumbers(s)
 	n := strings.Builder{}
 	n.Grow(len(s) + 2) // nominal 2 bytes of extra space for inserted delimiters
 	start := true
@@ -99,10 +98,12 @@ func ToScreamingDelimited(s string, delimiter uint8, ignore uint8, screaming boo
 		// treat acronyms as words, eg for JSONData -> JSON is a whole word
 		if i+1 < len(s) {
 			next := s[i+1]
+			vIsNum := v >= '0' && v <= '9'
 			nextIsCap := next >= 'A' && next <= 'Z'
 			nextIsLow := next >= 'a' && next <= 'z'
+			nextIsNum := next >= '0' && next <= '9'
 			// add underscore if next letter case type is changed
-			if (vIsCap && nextIsLow) || (vIsLow && nextIsCap) {
+			if (vIsCap && (nextIsLow || nextIsNum)) || (vIsLow && (nextIsCap || nextIsNum)) || (vIsNum && (nextIsCap || nextIsLow)) {
 				if prevIgnore := ignore > 0 && i > 0 && s[i-1] == ignore; !prevIgnore {
 					if vIsCap && nextIsLow {
 						if prevIsCap := i > 0 && s[i-1] >= 'A' && s[i-1] <= 'Z'; prevIsCap {
@@ -110,7 +111,7 @@ func ToScreamingDelimited(s string, delimiter uint8, ignore uint8, screaming boo
 						}
 					}
 					n.WriteByte(v)
-					if vIsLow {
+					if vIsLow || vIsNum || nextIsNum {
 						n.WriteByte(delimiter)
 					}
 					continue
diff --git a/snake_test.go b/snake_test.go
index 5482999..2e34372 100644
--- a/snake_test.go
+++ b/snake_test.go
@@ -48,6 +48,12 @@ func toSnake(tb testing.TB) {
 		{"JSONData", "json_data"},
 		{"userID", "user_id"},
 		{"AAAbbb", "aa_abbb"},
+		{"1A2", "1_a_2"},
+		{"A1B", "a_1_b"},
+		{"A1A2A3", "a_1_a_2_a_3"},
+		{"A1 A2 A3", "a_1_a_2_a_3"},
+		{"AB1AB2AB3", "ab_1_ab_2_ab_3"},
+		{"AB1 AB2 AB3", "ab_1_ab_2_ab_3"},
 	}
 	for _, i := range cases {
 		in := i[0]