From f3aec200001f1a012919d89d02ee6bcbe21fe914 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 15 Sep 2023 00:44:15 +0300
Subject: [PATCH] all: support `;` statements, allowing for oneliners like `./v
 -e 'import os; println( os.ls(os.args[1])!.sorted(a > b) )' vlib/math`
 (#19345)

---
 cmd/tools/vast/vast.v                   |  7 +++++++
 vlib/v/ast/ast.v                        |  6 ++++++
 vlib/v/checker/checker.v                |  1 +
 vlib/v/fmt/fmt.v                        | 13 +++++++++----
 vlib/v/fmt/tests/semicolons_expected.vv |  4 ++++
 vlib/v/fmt/tests/semicolons_input.vv    |  4 ++++
 vlib/v/gen/c/cgen.v                     |  3 +++
 vlib/v/gen/golang/golang.v              |  3 +++
 vlib/v/gen/js/js.v                      |  6 ++++++
 vlib/v/markused/walker.v                |  1 +
 vlib/v/parser/parser.v                  | 13 ++++++++++++-
 vlib/v/transformer/transformer.v        |  1 +
 12 files changed, 57 insertions(+), 5 deletions(-)
 create mode 100644 vlib/v/fmt/tests/semicolons_expected.vv
 create mode 100644 vlib/v/fmt/tests/semicolons_input.vv

diff --git a/cmd/tools/vast/vast.v b/cmd/tools/vast/vast.v
index 5100b4041703b5..c7e5174b84ca33 100644
--- a/cmd/tools/vast/vast.v
+++ b/cmd/tools/vast/vast.v
@@ -435,6 +435,7 @@ fn (t Tree) stmt(node ast.Stmt) &Node {
 		ast.AssertStmt { return t.assert_stmt(node) }
 		ast.ExprStmt { return t.expr_stmt(node) }
 		ast.Block { return t.block(node) }
+		ast.SemicolonStmt { return t.semicolon_stmt(node) }
 		ast.SqlStmt { return t.sql_stmt(node) }
 		ast.AsmStmt { return t.asm_stmt(node) }
 		ast.NodeError { return t.node_error(node) }
@@ -1747,6 +1748,12 @@ fn (t Tree) sql_expr(node ast.SqlExpr) &Node {
 	return obj
 }
 
+fn (t Tree) semicolon_stmt(node ast.SemicolonStmt) &Node {
+	mut obj := new_object()
+	obj.add('pos', t.pos(node.pos))
+	return obj
+}
+
 fn (t Tree) sql_stmt(node ast.SqlStmt) &Node {
 	mut obj := new_object()
 	obj.add_terse('ast_type', t.string_node('SqlStmt'))
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index c64a84fc7c1963..2fddcef480d21e 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -87,6 +87,7 @@ pub type Stmt = AsmStmt
 	| Module
 	| NodeError
 	| Return
+	| SemicolonStmt
 	| SqlStmt
 	| StructDecl
 	| TypeDecl
@@ -300,6 +301,11 @@ pub:
 	is_skipped bool      // module main can be skipped in single file programs
 }
 
+pub struct SemicolonStmt {
+pub:
+	pos token.Pos
+}
+
 [minify]
 pub struct StructField {
 pub:
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 153514fcade957..7ab7606e081626 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -2099,6 +2099,7 @@ fn (mut c Checker) stmt(mut node ast.Stmt) {
 			c.return_stmt(mut node)
 			c.scope_returns = true
 		}
+		ast.SemicolonStmt {}
 		ast.SqlStmt {
 			c.sql_stmt(mut node)
 		}
diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index f85181ffab824d..4b15f48fa3270d 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -85,12 +85,12 @@ pub fn fmt(file ast.File, table &ast.Table, pref_ &pref.Preferences, is_debug bo
 		imp_str := f.out_imports.str().trim_space()
 		if imp_str.len > 0 {
 			return res + '\n' + imp_str + '\n'
-		} else {
-			return res
 		}
-	} else {
-		return res[..f.import_pos] + f.out_imports.str() + res[f.import_pos..]
+		return res
 	}
+	source_for_imports := res[..f.import_pos] + f.out_imports.str()
+	source_after_imports := res[f.import_pos..]
+	return source_for_imports + source_after_imports
 }
 
 pub fn (mut f Fmt) process_file_imports(file &ast.File) {
@@ -405,6 +405,9 @@ fn (f Fmt) should_insert_newline_before_node(node ast.Node, prev_node ast.Node)
 					return true
 				}
 			}
+			ast.SemicolonStmt {
+				return false
+			}
 			// Force a newline after struct declarations
 			ast.StructDecl {
 				return true
@@ -552,6 +555,7 @@ pub fn (mut f Fmt) stmt(node ast.Stmt) {
 		ast.Return {
 			f.return_stmt(node)
 		}
+		ast.SemicolonStmt {}
 		ast.SqlStmt {
 			f.sql_stmt(node)
 		}
@@ -568,6 +572,7 @@ fn stmt_is_single_line(stmt ast.Stmt) bool {
 	return match stmt {
 		ast.ExprStmt, ast.AssertStmt { expr_is_single_line(stmt.expr) }
 		ast.Return, ast.AssignStmt, ast.BranchStmt { true }
+		ast.SemicolonStmt { true }
 		else { false }
 	}
 }
diff --git a/vlib/v/fmt/tests/semicolons_expected.vv b/vlib/v/fmt/tests/semicolons_expected.vv
new file mode 100644
index 00000000000000..ad5bc934eabe9d
--- /dev/null
+++ b/vlib/v/fmt/tests/semicolons_expected.vv
@@ -0,0 +1,4 @@
+import os
+
+println(os.args)
+println('hello')
diff --git a/vlib/v/fmt/tests/semicolons_input.vv b/vlib/v/fmt/tests/semicolons_input.vv
new file mode 100644
index 00000000000000..dfd77e9c81dcd9
--- /dev/null
+++ b/vlib/v/fmt/tests/semicolons_input.vv
@@ -0,0 +1,4 @@
+import os;
+
+println(os.args);
+println('hello');
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index db3eac6985585f..ff9c37e9dc9436 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -2179,6 +2179,9 @@ fn (mut g Gen) stmt(node ast.Stmt) {
 		ast.Return {
 			g.return_stmt(node)
 		}
+		ast.SemicolonStmt {
+			g.writeln(';')
+		}
 		ast.SqlStmt {
 			g.sql_stmt(node)
 		}
diff --git a/vlib/v/gen/golang/golang.v b/vlib/v/gen/golang/golang.v
index 46c47dd299fe63..dfac3aaf961804 100644
--- a/vlib/v/gen/golang/golang.v
+++ b/vlib/v/gen/golang/golang.v
@@ -472,6 +472,9 @@ pub fn (mut f Gen) stmt(node ast.Stmt) {
 		ast.Return {
 			f.return_stmt(node)
 		}
+		ast.SemicolonStmt {
+			f.writeln(';')
+		}
 		ast.SqlStmt {
 			f.sql_stmt(node)
 		}
diff --git a/vlib/v/gen/js/js.v b/vlib/v/gen/js/js.v
index fdd55757a74fc0..3654f30f99ddb8 100644
--- a/vlib/v/gen/js/js.v
+++ b/vlib/v/gen/js/js.v
@@ -739,6 +739,9 @@ fn (mut g JsGen) stmt_no_semi(node_ ast.Stmt) {
 			}
 			g.gen_return_stmt(node)
 		}
+		ast.SemicolonStmt {
+			g.writeln(';')
+		}
 		ast.SqlStmt {}
 		ast.StructDecl {
 			g.write_v_source_line_info(node.pos)
@@ -842,6 +845,9 @@ fn (mut g JsGen) stmt(node_ ast.Stmt) {
 			}
 			g.gen_return_stmt(node)
 		}
+		ast.SemicolonStmt {
+			g.writeln(';')
+		}
 		ast.SqlStmt {}
 		ast.StructDecl {
 			g.write_v_source_line_info(node.pos)
diff --git a/vlib/v/markused/walker.v b/vlib/v/markused/walker.v
index 5bbf513c0f614f..363c8478380154 100644
--- a/vlib/v/markused/walker.v
+++ b/vlib/v/markused/walker.v
@@ -192,6 +192,7 @@ pub fn (mut w Walker) stmt(node_ ast.Stmt) {
 		ast.HashStmt {}
 		ast.Import {}
 		ast.InterfaceDecl {}
+		ast.SemicolonStmt {}
 		ast.Module {}
 		ast.TypeDecl {}
 		ast.NodeError {}
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index 31e374aff3100c..5f7ce9e7f0334f 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -1122,6 +1122,9 @@ fn (mut p Parser) stmt(is_top_level bool) ast.Stmt {
 		.key_asm {
 			return p.asm_stmt(false)
 		}
+		.semicolon {
+			return p.semicolon_stmt()
+		}
 		// literals, 'if', etc. in here
 		else {
 			return p.parse_multi_expr(is_top_level)
@@ -1129,6 +1132,14 @@ fn (mut p Parser) stmt(is_top_level bool) ast.Stmt {
 	}
 }
 
+fn (mut p Parser) semicolon_stmt() ast.SemicolonStmt {
+	pos := p.tok.pos()
+	p.check(.semicolon)
+	return ast.SemicolonStmt{
+		pos: pos
+	}
+}
+
 fn (mut p Parser) asm_stmt(is_top_level bool) ast.AsmStmt {
 	p.inside_asm = true
 	p.inside_asm_template = true
@@ -3647,7 +3658,7 @@ fn (mut p Parser) import_stmt() ast.Import {
 	}
 	pos_t := p.tok.pos()
 	if import_pos.line_nr == pos_t.line_nr {
-		if p.tok.kind !in [.lcbr, .eof, .comment] {
+		if p.tok.kind !in [.lcbr, .eof, .comment, .semicolon] {
 			p.error_with_pos('cannot import multiple modules at a time', pos_t)
 			return import_node
 		}
diff --git a/vlib/v/transformer/transformer.v b/vlib/v/transformer/transformer.v
index 24574c70a559d2..c1e4c7957151ba 100644
--- a/vlib/v/transformer/transformer.v
+++ b/vlib/v/transformer/transformer.v
@@ -281,6 +281,7 @@ pub fn (mut t Transformer) stmt(mut node ast.Stmt) ast.Stmt {
 				expr = t.expr(mut expr)
 			}
 		}
+		ast.SemicolonStmt {}
 		ast.SqlStmt {}
 		ast.StructDecl {
 			for mut field in node.fields {