builtin: string.index_after() ?int

.gitignore

@@ -155,3 +155,4 @@ bench/vectors/obj
 
 autofuzz.log
 .project.gf
+.aider*

cmd/tools/changelog_helper.v

@@ -311,7 +311,7 @@ fn (l Line) write_at_category(txt string) ?string {
 	title := category_map[l.category]
 	title_pos := txt.index(title)?
 	// Find the position of the ### category title
-	pos := txt.index_after('\n', title_pos + 1)
+	pos := txt.index_after('\n', title_pos + 1) or { return none }
 	first_half := txt[..pos]
 	second_half := txt[pos..]
 	if txt.contains(l.text) {

cmd/tools/vpm/common.v

@@ -104,24 +104,18 @@ fn get_all_modules() []string {
 		mut start_token := "<a href='/mod"
 		end_token := '</a>'
 		// get the start index of the module entry
-		mut start_index := s.index_after(start_token, read_len)
+		mut start_index := s.index_after(start_token, read_len) or { -1 }
 		if start_index == -1 {
 			start_token = '<a href="/mod'
-			start_index = s.index_after(start_token, read_len)
+			start_index = s.index_after(start_token, read_len) or { break }
-			if start_index == -1 {
-				break
-			}
 		}
 		// get the index of the end of anchor (a) opening tag
 		// we use the previous start_index to make sure we are getting a module and not just a random 'a' tag
 		start_token = '>'
-		start_index = s.index_after(start_token, start_index) + start_token.len
+		start_index = s.index_after(start_token, start_index) or { break } + start_token.len
 
 		// get the index of the end of module entry
-		end_index := s.index_after(end_token, start_index)
+		end_index := s.index_after(end_token, start_index) or { break }
-		if end_index == -1 {
-			break
-		}
 		modules << s[start_index..end_index]
 		read_len = end_index
 		if read_len >= s.len {

examples/links_scraper.v

@@ -4,11 +4,8 @@ fn main() {
 	html := http.get_text('https://news.ycombinator.com')
 	mut pos := 0
 	for {
-		pos = html.index_after('https://', pos + 1)
+		pos = html.index_after('https://', pos + 1) or { break }
-		if pos == -1 {
+		end := html.index_after('"', pos) or { break }
-			break
-		}
-		end := html.index_after('"', pos)
 		println(html[pos..end])
 	}
 }

vlib/builtin/js/string.js.v

@@ -707,7 +707,7 @@ pub fn (s string) replace_each(vals []string) string {
 		with_ = with_
 
 		for {
-			idx = s_.index_after(rep, idx)
+			idx = s_.index_after_(rep, idx)
 			if idx == -1 {
 				break
 			}
@@ -817,7 +817,37 @@ pub fn (s string) trim_space() string {
 	return res
 }
 
-pub fn (s string) index_after(p string, start int) int {
+pub fn (s string) index_after(p string, start int) ?int {
+	if p.len > s.len {
+		return none
+	}
+
+	mut strt := start
+	if start < 0 {
+		strt = 0
+	}
+	if start >= s.len {
+		return none
+	}
+	mut i := strt
+
+	for i < s.len {
+		mut j := 0
+		mut ii := i
+		for j < p.len && s[ii] == p[j] {
+			j++
+			ii++
+		}
+
+		if j == p.len {
+			return i
+		}
+		i++
+	}
+	return none
+}
+
+pub fn (s string) index_after_(p string, start int) int {
 	if p.len > s.len {
 		return -1
 	}

vlib/builtin/string.v

@@ -392,7 +392,7 @@ pub fn (s string) replace(rep string, with string) string {
 	}
 	mut idx := 0
 	for {
-		idx = s.index_after(rep, idx)
+		idx = s.index_after_(rep, idx)
 		if idx == -1 {
 			break
 		}
@@ -463,7 +463,7 @@ pub fn (s string) replace_each(vals []string) string {
 		with := vals[rep_i + 1]
 
 		for {
-			idx = s_.index_after(rep, idx)
+			idx = s_.index_after_(rep, idx)
 			if idx == -1 {
 				break
 			}
@@ -1352,7 +1352,36 @@ fn (s string) index_last_(p string) int {
 
 // index_after returns the position of the input string, starting search from `start` position.
 @[direct_array_access]
-pub fn (s string) index_after(p string, start int) int {
+pub fn (s string) index_after(p string, start int) ?int {
+	if p.len > s.len {
+		return none
+	}
+	mut strt := start
+	if start < 0 {
+		strt = 0
+	}
+	if start >= s.len {
+		return none
+	}
+	mut i := strt
+	for i < s.len {
+		mut j := 0
+		mut ii := i
+		for j < p.len && unsafe { s.str[ii] == p.str[j] } {
+			j++
+			ii++
+		}
+		if j == p.len {
+			return i
+		}
+		i++
+	}
+	return none
+}
+
+// index_after_ returns the position of the input string, starting search from `start` position.
+@[direct_array_access]
+pub fn (s string) index_after_(p string, start int) int {
 	if p.len > s.len {
 		return -1
 	}
@@ -1429,7 +1458,7 @@ pub fn (s string) count(substr string) int {
 
 	mut i := 0
 	for {
-		i = s.index_after(substr, i)
+		i = s.index_after_(substr, i)
 		if i == -1 {
 			return n
 		}

vlib/encoding/csv/reader.v

@@ -95,11 +95,11 @@ fn (mut r Reader) read_line() !string {
 		return &EndOfFileError{}
 	}
 	le := if r.is_mac_pre_osx_le { '\r' } else { '\n' }
-	mut i := r.data.index_after(le, r.row_pos)
+	mut i := r.data.index_after(le, r.row_pos) or { -1 }
 	if i == -1 {
 		if r.row_pos == 0 {
 			// check for pre osx mac line endings
-			i = r.data.index_after('\r', r.row_pos)
+			i = r.data.index_after('\r', r.row_pos) or { -1 }
 			if i != -1 {
 				r.is_mac_pre_osx_le = true
 			} else {

vlib/net/http/util.v

@@ -8,9 +8,6 @@ module http
 // "GET / HTTP/1.1" => ["GET" "/" "HTTP/1.1"]
 fn fast_request_words(line string) (int, int) {
 	space1 := line.index(' ') or { return 0, 0 }
-	space2 := line.index_after(' ', space1 + 1)
+	space2 := line.index_after(' ', space1 + 1) or { return 0, 0 }
-	if space2 == -1 {
-		return 0, 0
-	}
 	return space1, space2
 }

vlib/v/ast/cflags.v

@@ -64,7 +64,7 @@ pub fn (mut t Table) parse_cflag(cflg string, mod string, ctimedefines []string)
 			if has_next {
 				break
 			}
-			index = flag.index_after(' -', index + 1)
+			index = flag.index_after(' -', index + 1) or { -1 }
 		}
 		if index == -1 {
 			value = flag.trim_space()

vlib/v/checker/checker.v

@@ -3367,6 +3367,7 @@ fn (mut c Checker) cast_expr(mut node ast.CastExpr) ast.Type {
 	}
 	c.check_any_type(to_type, to_sym, node.pos)
 
+	if c.pref.backend.is_js() {
 		if (to_sym.is_number() && from_sym.name == 'JS.Number')
 			|| (to_sym.is_number() && from_sym.name == 'JS.BigInt')
 			|| (to_sym.is_string() && from_sym.name == 'JS.String')
@@ -3377,6 +3378,7 @@ fn (mut c Checker) cast_expr(mut node ast.CastExpr) ast.Type {
 			|| (from_sym.is_string() && to_sym.name == 'JS.String') {
 			return to_type
 		}
+	}
 
 	if !c.expected_type.has_flag(.generic) && to_sym.name.len == 1
 		&& to_sym.name.starts_with_capital() {

vlib/v/eval/expr.c.v

@@ -579,12 +579,15 @@ pub fn (mut e Eval) expr(expr ast.Expr, expecting ast.Type) Object {
 			}
 			e.error('unhandled index expression ${left}[ ${index} ]')
 		}
+		ast.OrExpr {
+			e.error('unhandled expression ${typeof(expr).name}')
+		}
 		ast.AnonFn, ast.ArrayDecompose, ast.AsCast, ast.Assoc, ast.AtExpr, ast.CTempVar,
 		ast.ChanInit, ast.Comment, ast.ComptimeCall, ast.ComptimeSelector, ast.ComptimeType,
 		ast.ConcatExpr, ast.DumpExpr, ast.EmptyExpr, ast.EnumVal, ast.GoExpr, ast.SpawnExpr,
 		ast.IfGuardExpr, ast.IsRefType, ast.Likely, ast.LockExpr, ast.MapInit, ast.MatchExpr,
-		ast.Nil, ast.None, ast.OffsetOf, ast.OrExpr, ast.RangeExpr, ast.SelectExpr, ast.SqlExpr,
+		ast.Nil, ast.None, ast.OffsetOf, ast.RangeExpr, ast.SelectExpr, ast.SqlExpr, ast.TypeNode,
-		ast.TypeNode, ast.TypeOf, ast.LambdaExpr {
+		ast.TypeOf, ast.LambdaExpr {
 			e.error('unhandled expression ${typeof(expr).name}')
 		}
 	}

vlib/v/scanner/scanner.v

@@ -1506,10 +1506,7 @@ fn trim_slash_line_break(s string) string {
 	mut ret_str := s
 	for {
 		// find the position of the first `\` followed by a newline, after `start`:
-		idx := ret_str.index_after('\\\n', start)
+		idx := ret_str.index_after('\\\n', start) or { break }
-		if idx == -1 {
-			break
-		}
 		start = idx
 		// Here, ret_str[idx] is \, and ret_str[idx+1] is newline.
 		// Depending on the number of backslashes before the newline, we should either