bytes: add function to get indexes of word in string

Unlike Indexes, the word parameter must be separated by space or placed
at beginning or end of string.

4 files changed, 47 insertions, 0 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 8e24d10c..5d0d29d8 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -9,6 +9,8 @@ This library is released each month, usually at the first week of month.
 
 ===  New Features
 
+*  bytes: add function to get all indexes of word in string
+
 *  bytes: add function to take snippets from string by indexes
 
 *  bytes: add function to get all indexes of token in string
diff --git a/CHANGELOG.html b/CHANGELOG.html
index b4795591..9703b9ad 100644
--- a/CHANGELOG.html
+++ b/CHANGELOG.html
@@ -115,6 +115,9 @@
 <div class="ulist">
 <ul>
 <li>
+<p>bytes: add function to get all indexes of word in string</p>
+</li>
+<li>
 <p>bytes: add function to take snippets from string by indexes</p>
 </li>
 <li>
diff --git a/lib/bytes/bytes.go b/lib/bytes/bytes.go
index 4db067a0..54a7856a 100644
--- a/lib/bytes/bytes.go
+++ b/lib/bytes/bytes.go
@@ -9,6 +9,7 @@ import (
 	"bytes"
 	"fmt"
 	"reflect"
+	"unicode"
 )
 
 //
@@ -510,6 +511,37 @@ func TokenFind(line, token []byte, startat int) (at int) {
 }
 
 //
+// WordIndexes returns the index of the all instance of word in s as long as
+// word is separated by space or at the beginning or end of s.
+//
+func WordIndexes(s []byte, word []byte) (idxs []int) {
+	tmp := Indexes(s, word)
+	if len(tmp) == 0 {
+		return nil
+	}
+
+	for _, idx := range tmp {
+		x := idx - 1
+		if x >= 0 {
+			if !unicode.IsSpace(rune(s[x])) {
+				continue
+			}
+		}
+		x = idx + len(word)
+		if x >= len(s) {
+			idxs = append(idxs, idx)
+			continue
+		}
+		if !unicode.IsSpace(rune(s[x])) {
+			continue
+		}
+		idxs = append(idxs, idx)
+	}
+
+	return idxs
+}
+
+//
 // WriteUint16 into slice of byte.
 //
 func WriteUint16(data *[]byte, x uint, v uint16) {
diff --git a/lib/bytes/bytes_example_test.go b/lib/bytes/bytes_example_test.go
index 06b96146..dcb0e1ec 100644
--- a/lib/bytes/bytes_example_test.go
+++ b/lib/bytes/bytes_example_test.go
@@ -128,3 +128,13 @@ func ExampleTokenFind() {
 	fmt.Printf("%d\n", at)
 	// Output: 7
 }
+
+func ExampleWordIndexes() {
+	s := []byte("moo moomoo moo")
+	token := []byte("moo")
+
+	idxs := WordIndexes(s, token)
+	fmt.Println(idxs)
+	// Output:
+	// [0 11]
+}