repl: fix import xxx with no fn main error

vlib/v/checker/tests/no_fn_main.out

@@ -1,5 +0,0 @@
-vlib/v/checker/tests/no_fn_main.v:1:1: error: function `main` must be declared in the main module
-    1 | fn no_main() {
-      | ^
-    2 |     println('Hello world !')
-    3 | }

vlib/v/checker/tests/no_fn_main.vv

@@ -1,3 +0,0 @@
-fn no_main() {
-	println('Hello world !')
-}

vlib/v/parser/fn.v

@@ -401,3 +401,18 @@ fn (mut p Parser) fn_redefinition_error(name string) {
 	*/
 	p.error('redefinition of function `$name`')
 }
+
+fn have_fn_main(stmts []ast.Stmt) bool {
+	mut has_main_fn := false
+	for stmt in stmts {
+		match stmt {
+			ast.FnDecl {
+				if it.name == 'main' {
+					has_main_fn = true
+				}
+			}
+			else {}
+		}
+	}
+	return has_main_fn
+}

vlib/v/parser/parser.v

@@ -63,7 +63,7 @@ pub fn parse_stmt(text string, table &table.Table, scope &ast.Scope) ast.Stmt {
 	return p.stmt()
 }
 
-pub fn parse_file(path string, table &table.Table, comments_mode scanner.CommentsMode, pref &pref.Preferences, global_scope &ast.Scope) ast.File {
+pub fn parse_file(path string, b_table &table.Table, comments_mode scanner.CommentsMode, pref &pref.Preferences, global_scope &ast.Scope) ast.File {
 	// println('parse_file("$path")')
 	// text := os.read_file(path) or {
 	// panic(err)
@@ -71,7 +71,7 @@ pub fn parse_file(path string, table &table.Table, comments_mode scanner.Comment
 	mut stmts := []ast.Stmt{}
 	mut p := Parser{
 		scanner: scanner.new_scanner_file(path, comments_mode)
-		table: table
+		table: b_table
 		file_name: path
 		file_name_dir: os.dir(path)
 		pref: pref
@@ -102,9 +102,13 @@ pub fn parse_file(path string, table &table.Table, comments_mode scanner.Comment
 	*/
 	// TODO: import only mode
 	for {
-		// res := s.scan()
 		if p.tok.kind == .eof {
-			// println('EOF, breaking')
+			if p.pref.is_script && !p.pref.is_test && p.mod == 'main' && !have_fn_main(stmts) {
+				stmts << ast.FnDecl {
+					name: 'main'
+					return_type: table.void_type
+				}
+			}
 			break
 		}
 		// println('stmt at ' + p.tok.str())
@@ -350,7 +354,7 @@ pub fn (mut p Parser) top_stmt() ast.Stmt {
 		}
 		else {
 			if p.pref.is_script && !p.pref.is_test {
-				p.scanner.add_fn_main_and_rescan()
+				p.scanner.add_fn_main_and_rescan(p.tok.pos-1)
 				p.read_first_token()
 				return p.top_stmt()
 			} else {

vlib/v/scanner/scanner.v

@@ -75,12 +75,17 @@ pub fn new_scanner(text string, comments_mode CommentsMode) &Scanner {
 	return s
 }
 
-pub fn (s &Scanner) add_fn_main_and_rescan() {
-	s.text = 'fn main() {' + s.text + '}'
-	s.is_started = false
-	s.pos = 0
-	s.line_nr = 0
-	s.last_nl_pos = 0
+pub fn (s &Scanner) add_fn_main_and_rescan(pos int) {
+	if pos > 0 {
+		s.text = s.text[..pos] + 'fn main() {' + s.text[pos..] + '}'
+		s.pos = pos
+		s.is_started = false
+	} else {
+		s.text = 'fn main() {' + s.text + '}'
+		s.pos = 0
+		s.line_nr = 0
+		s.is_started = false
+	}
 }
 
 fn (s &Scanner) new_token(tok_kind token.Kind, lit string, len int) token.Token {

vlib/v/tests/repl/array.repl

@@ -0,0 +1,7 @@
+mut a := [1, 2, 3]
+b := [4, 5]
+a << b
+a = a.filter(it%2==0)
+a
+===output===
+[2, 4]

vlib/v/tests/repl/import.repl

@@ -0,0 +1,4 @@
+import time
+time.now().unix_time() > 160000
+===output===
+true