string: make index() return ?int instead of int/-1

vlib/compiler/cflags.v

@@ -84,7 +84,7 @@ fn (table mut Table) parse_cflag(cflag string, mod string) ?bool {
 	mut fos := ''
 	mut name := ''
 	if flag.starts_with('linux') || flag.starts_with('darwin') || flag.starts_with('freebsd') || flag.starts_with('windows') {
-		pos := flag.index(' ')
+		pos := flag.index(' ') or { return none }
 		fos = flag[..pos].trim_space()
 		flag = flag[pos..].trim_space()
 	}
@@ -101,16 +101,21 @@ fn (table mut Table) parse_cflag(cflag string, mod string) ?bool {
 				}
 			}
 		}
-		for i in [flag.index(' '), flag.index(',')] {
-			if index == -1 || (i != -1 && i < index) {
+		if i := flag.index(' ') {
+			if index == -1 || i < index {
+				index = i
+			}
+		}
+		if i := flag.index(',') {
+			if index == -1 || i < index {
 				index = i
 			}
 		}
 		if index != -1 && flag[index] == ` ` && flag[index+1] == `-` {
 			for f in allowed_flags {
-				i := index+f.len
-				if i < flag.len && f == flag[index..i] {
-					index = i
+				j := index+f.len
+				if j < flag.len && f == flag[index..j] {
+					index = j
 					break
 				}
 			}
@@ -149,7 +154,7 @@ fn (table mut Table) parse_cflag(cflag string, mod string) ?bool {
 fn (cflags []CFlag) c_options_before_target_msvc() string { return '' }
 fn (cflags []CFlag) c_options_after_target_msvc() string { return '' }
 
-fn (cflags []CFlag) c_options_before_target() string {	
+fn (cflags []CFlag) c_options_before_target() string {
 	// -I flags, optimization flags and so on
 	mut args:=[]string
 	for flag in cflags {
@@ -185,7 +190,7 @@ fn (cflags []CFlag) c_options_without_object_files() string {
 fn (cflags []CFlag) c_options_only_object_files() string {
 	mut args:=[]string
 	for flag in cflags {
-		if flag.value.ends_with('.o') || flag.value.ends_with('.obj') { 
+		if flag.value.ends_with('.o') || flag.value.ends_with('.obj') {
 			args << flag.format()
 		}
 	}

vlib/compiler/comptime.v

@@ -39,7 +39,7 @@ fn (p mut Parser) comp_time() {
 				for {
 					if p.tok == .key_return {
 						p.returns = true
-					}	
+					}
 					if p.tok == .lcbr {
 						stack++
 					} else if p.tok == .rcbr {
@@ -114,7 +114,7 @@ fn (p mut Parser) comp_time() {
 			//p.gen('/* returns $p.returns */')
 		} else if p.tok == .key_else {
 			p.error('use `$' + 'else` instead of `else` in comptime if statements')
-		}	
+		}
 	}
 	else if p.tok == .key_for {
 		p.next()
@@ -207,7 +207,7 @@ fn (p mut Parser) chash() {
 			if !p.pref.building_v && !p.fileis('vlib') {
 				p.warn('C #includes will soon be removed from the language' +
 				'\ndefine the C structs and functions in V')
-			}	
+			}
 			*/
 			if p.file_pcguard.len != 0 {
 				//println('p: $p.file_platform $p.file_pcguard')
@@ -220,8 +220,8 @@ fn (p mut Parser) chash() {
 	}
 	// TODO remove after ui_mac.m is removed
 	else if hash.contains('embed') {
-		pos := hash.index('embed') + 5
-		file := hash[pos..]
+		pos := hash.index('embed') or { return }
+		file := hash[pos+5..]
 		//if p.pref.build_mode != .default_mode {
 			p.genln('#include $file')
 		//}
@@ -262,13 +262,13 @@ fn (p mut Parser) comptime_method_call(typ Type) {
 	mut j := 0
 	for i, method in typ.methods {
 		if method.typ != 'void' {
-			
+
 			continue
 		}
 		receiver := method.args[0]
 		if !p.expr_var.ptr {
 			p.error('`$p.expr_var.name` needs to be a reference')
-		}	
+		}
 		amp := if receiver.is_mut && !p.expr_var.ptr { '&' } else { '' }
 		if j > 0 {
 			p.gen(' else ')
@@ -290,7 +290,7 @@ fn (p mut Parser) comptime_method_call(typ Type) {
 fn (p mut Parser) gen_array_str(typ Type) {
 	if typ.has_method('str') {
 		return
-	}	
+	}
 	p.add_method(typ.name, Fn{
 		name: 'str'
 		typ: 'string'
@@ -381,7 +381,7 @@ fn (p mut Parser) gen_array_filter(str_typ string, method_ph int) {
 		// V
 		a := [1,2,3,4]
 		b := a.filter(it % 2 == 0)
-		
+
 		// C
 		array_int a = ...;
 		array_int tmp2 = new_array(0, 4, 4);
@@ -421,7 +421,7 @@ fn (p mut Parser) gen_array_map(str_typ string, method_ph int) string {
 		// V
 		a := [1,2,3,4]
 		b := a.map(it * 2)
-		
+
 		// C
 		array_int a = ...;
 		array_int tmp2 = new_array(0, 4, 4);

vlib/compiler/main.v

@@ -799,8 +799,7 @@ pub fn get_arg(joined_args, arg, def string) string {
 
 pub fn get_param_after(joined_args, arg, def string) string {
 	key := '$arg '
-	mut pos := joined_args.index(key)
-	if pos == -1 {
+	mut pos := joined_args.index(key) or {
 		return def
 	}
 	pos += key.len

vlib/compiler/parser.v

@@ -1068,9 +1068,12 @@ fn (p mut Parser) get_type() string {
 		//}
 		return 'void*'
 	}
+	/*
+	TODO this is not needed?
 	if typ.last_index('__') > typ.index('__') {
 		p.error('2 __ in gettype(): typ="$typ"')
 	}
+	*/
 	return typ
 }
 
@@ -1410,8 +1413,10 @@ fn ($v.name mut $v.typ) $p.cur_fn.name (...) {
 	{
 		line := p.cgen.cur_line
 		vname := line[..pos].replace('=','') // TODO cgen line hack
-		p.cgen.resetln(line.replace(line[..line.index('=')+1], ''))
-		p.gen_handle_option_or_else(expr_type, vname, ph)
+		if idx := line.index('=') {
+			p.cgen.resetln(line.replace(line[..idx+1], ''))
+			p.gen_handle_option_or_else(expr_type, vname, ph)
+		}
 	}
 	else if expr_type[0]==`[` {
 		// assignment to a fixed_array `mut a:=[3]int a=[1,2,3]!!`
@@ -3053,12 +3058,10 @@ fn (p mut Parser) defer_st() {
 }
 
 fn (p mut Parser) check_and_register_used_imported_type(typ_name string) {
-	us_idx := typ_name.index('__')
-	if us_idx != -1 {
-		arg_mod := typ_name[..us_idx]
-		if p.import_table.known_alias(arg_mod) {
-			p.import_table.register_used_import(arg_mod)
-		}
+	us_idx := typ_name.index('__') or { return }
+	arg_mod := typ_name[..us_idx]
+	if p.import_table.known_alias(arg_mod) {
+		p.import_table.register_used_import(arg_mod)
 	}
 }
 

vlib/compiler/parser2.v

@@ -157,8 +157,10 @@ fn (p mut Parser) get_type2() Type {
 		typ = 'Option_$typ'
 		p.table.register_type_with_parent(typ, 'Option')
 	}
+	/*
 	if typ.last_index('__') > typ.index('__') {
 		p.error('2 __ in gettype(): typ="$typ"')
 	}
+	*/
 	return Type{name: typ, cat: cat}
 }

vlib/compiler/table.v

@@ -931,8 +931,8 @@ fn (p &Parser) identify_typo(name string) string {
 // compare just name part, some items are mod prefied
 fn typo_compare_name_mod(a, b, b_mod string) f32 {
 	if a.len - b.len > 2 || b.len - a.len > 2 { return 0 }
-	auidx := a.index('__')
-	buidx := b.index('__')
+	auidx := a.index('__') or { -1 }
+	buidx := b.index('__') or { -1 }
 	a_mod := if auidx != -1 { mod_gen_name_rev(a[..auidx]) } else { '' }
 	a_name := if auidx != -1 { a[auidx+2..] } else { a }
 	b_name := if buidx != -1 { b[buidx+2..] } else { b }