StringsBuilder => strings.Builder; strings.repeat()

vlib/builtin/array.v

@@ -25,6 +25,12 @@ fn new_array(mylen, cap, elm_size int) array {
 	return arr
 }
 
+
+// TODO 
+pub fn _make(len, cap, elm_size int) array {
+	return new_array(len, cap, elm_size) 
+} 
+
 // Private function, used by V (`nums := [1, 2, 3]`)
 fn new_array_from_c_array(len, cap, elm_size int, c_array voidptr) array {
 	arr := array {

vlib/builtin/string.v

@@ -795,18 +795,6 @@ pub fn (c byte) is_white() bool {
 	return i == 10 || i == 32 || i == 9 || i == 13 || c == `\r`
 }
 
-// TODO move this to strings.repeat()
-pub fn repeat_char(c byte, n int) string {
-	if n <= 0 {
-		return ''
-	}
-	mut arr := malloc(n + 1)
-	for i := 0; i < n; i++ {
-		arr[i] = c
-	}
-	arr[n] = `\0`
-	return tos(arr, n)
-}
 
 pub fn (s string) hash() int {
 	mut hash := int(0)

vlib/strings/builder.v

@@ -2,38 +2,39 @@
 // Use of this source code is governed by an MIT license
 // that can be found in the LICENSE file.
 
-module builtin
+module strings 
 
-struct StringBuilder {
+struct Builder {
+mut: 
 	buf []byte
 	len int
 }
 
-pub fn new_string_builder(initial_size int) StringBuilder {
-	return StringBuilder {
-		buf: new_array(0, initial_size, sizeof(byte))
+pub fn new_builder(initial_size int) Builder {
+	return Builder {
+		buf: _make(0, initial_size, sizeof(byte))
 	}
 }
 
-pub fn (b mut StringBuilder) write(s string) {
+pub fn (b mut Builder) write(s string) {
 	b.buf._push_many(s.str, s.len)
 	b.len += s.len
 }
 
-pub fn (b mut StringBuilder) writeln(s string) {
+pub fn (b mut Builder) writeln(s string) {
 	b.buf._push_many(s.str, s.len)
 	b.buf << `\n`
 	b.len += s.len + 1
 }
 
-pub fn (b StringBuilder) str() string {
+pub fn (b Builder) str() string {
 	return tos(b.buf.data, b.len)
 }
 
-pub fn (b StringBuilder) cut(n int) {
+pub fn (b Builder) cut(n int) {
 	b.len -= n
 }
 
-pub fn (b mut StringBuilder) free() {
+pub fn (b mut Builder) free() {
 	C.free(b.buf.data)
 }

vlib/strings/builder_test.v

@@ -0,0 +1,15 @@
+import strings
+ 
+fn test_sb() {
+	mut sb := strings.Builder{}
+	sb.write('hi')
+	sb.write('!')
+	sb.write('hello')
+	assert sb.str() == 'hi!hello'
+	sb = strings.new_builder(10)
+	sb.write('a')
+	sb.write('b')
+	println(sb.str())
+	assert sb.str() == 'ab'
+}
+

vlib/strings/strings.v

@@ -0,0 +1,13 @@
+module strings 
+
+pub fn repeat(c byte, n int) string {
+	if n <= 0 {
+		return ''
+	}
+	mut arr := malloc(n + 1)
+	for i := 0; i < n; i++ {
+		arr[i] = c
+	}
+	arr[n] = `\0`
+	return tos(arr, n)
+}

vlib/strings/strings_test.v

@@ -0,0 +1,6 @@
+import strings
+
+fn test_repeat() {
+	assert strings.repeat(`x`, 10) == 'xxxxxxxxxx' 
+	assert strings.repeat(`a`, 1) == 'a' 
+}