cgen: treat the main module like any other v module

vlib/strings/builder.v

@@ -49,21 +49,26 @@ pub fn (mut b Builder) go_back(n int) {
 	b.len -= n
 }
 
+fn bytes2string(b []byte) string {
+	mut copy := b.clone()
+	copy << `\0`
+	res := tos(copy.data, copy.len-1)
+	return res
+}
+
 pub fn (mut b Builder) cut_last(n int) string {
-	buf := b.buf[b.len-n..]
-	s := string(buf.clone())
+	res := bytes2string( b.buf[b.len-n..] )
 	b.buf.trim(b.buf.len-n)
 	b.len -= n
-	return s
+	return res
 }
 
 /*
 pub fn (mut b Builder) cut_to(pos int) string {
-	buf := b.buf[pos..]
-	s := string(buf.clone())
+	res := bytes2string( b.buf[pos..] )
 	b.buf.trim(pos)
 	b.len = pos
-	return s
+	return res
 }
 */
 
@@ -88,8 +93,7 @@ pub fn (b &Builder) last_n(n int) string {
 	if n > b.len {
 		return ''
 	}
-	buf := b.buf[b.len-n..]
-	return string(buf.clone())
+	return bytes2string( b.buf[b.len-n..] )
 }
 
 // buf == 'hello world'
@@ -98,10 +102,7 @@ pub fn (b &Builder) after(n int) string {
 	if n >= b.len {
 		return ''
 	}
-	buf := b.buf[n..]
-	mut copy := buf.clone()
-	copy << `\0`
-	return string(copy)
+	return bytes2string( b.buf[n..] )
 }
 
 // NB: in order to avoid memleaks and additional memory copies, after a call to b.str(),

vlib/strings/builder_test.v

@@ -6,7 +6,8 @@ fn test_sb() {
 	sb.write('!')
 	sb.write('hello')
 	assert sb.len == 8
-	assert sb.str() == 'hi!hello'
+	sb_end := sb.str()
+	assert sb_end == 'hi!hello'
 	assert sb.len == 0
 	///
 	sb = strings.new_builder(10)
@@ -19,39 +20,33 @@ fn test_sb() {
 		// TODO msvc bug
 		sb = strings.new_builder(10)
 		sb.write('123456')
-		assert sb.cut_last(2) == '56'
-		assert sb.str() == '1234'
+		last_2 := sb.cut_last(2)
+		assert last_2 == '56'
+		final_sb := sb.str()
+		assert final_sb == '1234'
 	}
-	///
-	/*
-	sb = strings.new_builder(10)
-	sb.write('123456')
-	x := sb.cut_to(2)
-	assert x == '456'
-	assert sb.str() == '123'
-	*/
 }
 
 const (
-	n = 100000
+	maxn = 100000
 )
 
 fn test_big_sb() {
 	mut sb := strings.new_builder(100)
 	mut sb2 := strings.new_builder(10000)
-	for i in 0..n {
+	for i in 0..maxn {
 		sb.writeln(i.str())
 		sb2.write('+')
 	}
 	s := sb.str()
 	lines := s.split_into_lines()
-	assert lines.len == n
+	assert lines.len == maxn
 	assert lines[0] == '0'
 	assert lines[1] == '1'
 	assert lines[777] == '777'
 	assert lines[98765] == '98765'
 	println(sb2.len)
-	assert sb2.len == n
+	assert sb2.len == maxn
 
 }
 
@@ -64,5 +59,6 @@ fn test_byte_write() {
 		count++
 		assert count == sb.len
 	}
-	assert sb.str() == temp_str
+	sb_final := sb.str()
+	assert sb_final == temp_str
 }