vet: prohibit spaces after `(`

.github/workflows/ci.yml

@@ -45,6 +45,7 @@ jobs:
       run: ./v build-tools
     - name: v vet
       run: |
+        ./v vet vlib/v/scanner
         ./v vet vlib/v/parser
         ./v vet vlib/v/ast
         ./v vet vlib/v/gen/cgen.v

vlib/v/parser/parser.v

@@ -60,11 +60,12 @@ mut:
 
 // for tests
 pub fn parse_stmt(text string, table &table.Table, scope &ast.Scope) ast.Stmt {
-	s := scanner.new_scanner(text, .skip_comments, false)
+	pref:= &pref.Preferences{}
+	s := scanner.new_scanner(text, .skip_comments, pref)
 	mut p := Parser{
 		scanner: s
 		table: table
-		pref: &pref.Preferences{}
+		pref: pref
 		scope: scope
 		global_scope: &ast.Scope{
 			start_pos: 0
@@ -77,7 +78,7 @@ pub fn parse_stmt(text string, table &table.Table, scope &ast.Scope) ast.Stmt {
 }
 
 pub fn parse_text(text string, b_table &table.Table, pref &pref.Preferences, scope, global_scope &ast.Scope) ast.File {
-	s := scanner.new_scanner(text, .skip_comments, pref.is_fmt)
+	s := scanner.new_scanner(text, .skip_comments, pref)
 	mut p := Parser{
 		scanner: s
 		table: b_table
@@ -100,7 +101,7 @@ pub fn parse_file(path string, b_table &table.Table, comments_mode scanner.Comme
 	// panic(err)
 	// }
 	mut p := Parser{
-		scanner: scanner.new_scanner_file(path, comments_mode, pref.is_fmt)
+		scanner: scanner.new_scanner_file(path, comments_mode, pref)
 		comments_mode: comments_mode
 		table: b_table
 		file_name: path
@@ -126,6 +127,8 @@ pub fn parse_file(path string, b_table &table.Table, comments_mode scanner.Comme
 		eprintln('NB: You can run `v fmt -w file.v` to fix these automatically')
 		exit(1)
 	}
+	//if pref.is_vet && p.scanner.text.contains('( '\n        ') {
+	//}
 	return p.parse()
 }
 

vlib/v/parser/pratt.v

@@ -101,7 +101,7 @@ pub fn (mut p Parser) expr(precedence int) ast.Expr {
 			pos := p.tok.position()
 			p.next() // sizeof
 			p.check(.lpar)
-			is_known_var := p.mark_var_as_used( p.tok.lit )
+			is_known_var := p.mark_var_as_used(p.tok.lit)
 			if is_known_var {
 				expr := p.parse_ident(table.Language.v)
 				node = ast.SizeOf{
@@ -224,8 +224,9 @@ pub fn (mut p Parser) expr(precedence int) ast.Expr {
 			}
 		} else if p.tok.kind.is_infix() {
 			// return early for deref assign `*x = 2` goes to prefix expr
-			if p.tok.kind == .mul && p.tok.line_nr != p.prev_tok.line_nr && p.peek_tok2.kind ==
-				.assign {
+			if p.tok.kind == .mul &&
+				p.tok.line_nr != p.prev_tok.line_nr &&
+				p.peek_tok2.kind == .assign {
 				return node
 			}
 			// continue on infix expr

vlib/v/scanner/scanner.v

@@ -48,6 +48,7 @@ pub mut:
 	all_tokens                  []token.Token // *only* used in comments_mode: .toplevel_comments, contains all tokens
 	tidx                        int
 	eofs                        int
+	pref                        &pref.Preferences
 }
 
 /*
@@ -94,7 +95,8 @@ pub enum CommentsMode {
 }
 
 // new scanner from file.
-pub fn new_scanner_file(file_path string, comments_mode CommentsMode, is_fmt bool) &Scanner {
+pub fn new_scanner_file(file_path string, comments_mode CommentsMode, pref &pref.Preferences) &Scanner {
+	// is_fmt := pref.is_fmt
 	if !os.exists(file_path) {
 		verror("$file_path doesn't exist")
 	}
@@ -102,15 +104,17 @@ pub fn new_scanner_file(file_path string, comments_mode CommentsMode, is_fmt boo
 		verror(err)
 		return voidptr(0)
 	}
-	mut s := new_scanner(raw_text, comments_mode, is_fmt) // .skip_comments)
+	mut s := new_scanner(raw_text, comments_mode, pref) // .skip_comments)
 	// s.init_fmt()
 	s.file_path = file_path
 	return s
 }
 
 // new scanner from string.
-pub fn new_scanner(text string, comments_mode CommentsMode, is_fmt bool) &Scanner {
+pub fn new_scanner(text string, comments_mode CommentsMode, pref &pref.Preferences) &Scanner {
+	is_fmt := pref.is_fmt
 	s := &Scanner{
+		pref: pref
 		text: text
 		is_print_line_on_error: true
 		is_print_colored_error: true
@@ -768,6 +772,10 @@ fn (mut s Scanner) text_scan() token.Token {
 			return s.new_token(.chartoken, ident_char, ident_char.len + 2) // + two quotes
 		}
 		`(` {
+			// TODO `$if vet {` for performance
+			if s.pref.is_vet && s.text[s.pos + 1] == ` ` {
+				println('$s.file_path:$s.line_nr: Looks like you are adding a space after `(`')
+			}
 			return s.new_token(.lpar, '', 1)
 		}
 		`)` {

vlib/v/scanner/scanner_at_literals_test.v

@@ -42,7 +42,7 @@ fn fn_name_mod_level_high_order(cb fn(int)) {
 
 fn test_at_file() {
 	// Test @FILE
-    f := os.file_name( @FILE )
+	f := os.file_name(@FILE)
 	assert f == 'scanner_at_literals_test.v'
 }