From 3b6e66db0df71f4bf3d1a154bc48652ff323ec35 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kr=C3=BCger?=
 <45282134+UweKrueger@users.noreply.github.com>
Date: Thu, 18 Jun 2020 18:48:23 +0200
Subject: [PATCH] fmt: further fixes for string interpolation and builtin
 macros

---
 cmd/tools/vdoc.v                              |  2 +-
 cmd/tools/vfmt.v                              |  2 +-
 vlib/v/ast/str.v                              | 14 ++++++-
 vlib/v/fmt/fmt.v                              | 37 ++++++++++++++++---
 vlib/v/fmt/fmt_keep_test.v                    |  6 ++-
 vlib/v/fmt/fmt_test.v                         |  6 ++-
 vlib/v/fmt/fmt_vlib_test.v                    |  6 ++-
 .../tests/string_interpolation_expected.vv    | 10 +++++
 .../v/fmt/tests/string_interpolation_input.vv | 10 +++++
 vlib/v/parser/parser.v                        |  6 +--
 vlib/v/scanner/scanner.v                      | 15 +++++---
 vlib/v/scanner/scanner_test.v                 |  2 +-
 vlib/v/util/scanning.v                        |  6 ---
 13 files changed, 90 insertions(+), 32 deletions(-)

diff --git a/cmd/tools/vdoc.v b/cmd/tools/vdoc.v
index 24b9022235..30df2d5a4c 100644
--- a/cmd/tools/vdoc.v
+++ b/cmd/tools/vdoc.v
@@ -185,7 +185,7 @@ fn html_highlight(code string, tb &table.Table) string {
 		} else { tok.lit }
 		return if typ in [.unone, .name] { lit } else { '<span class="token $typ">$lit</span>' } 
 	}
-	s := scanner.new_scanner(code, .parse_comments)
+	s := scanner.new_scanner(code, .parse_comments, false)
 	mut tok := s.scan()
 	mut next_tok := s.scan()
 	mut buf := strings.new_builder(200)
diff --git a/cmd/tools/vfmt.v b/cmd/tools/vfmt.v
index b3fa461c75..af6b95c289 100644
--- a/cmd/tools/vfmt.v
+++ b/cmd/tools/vfmt.v
@@ -140,7 +140,7 @@ fn main() {
 
 fn (foptions &FormatOptions) format_file(file string) {
 	mut prefs := pref.new_preferences()
-	prefs.is_fmt = util.is_fmt()
+	prefs.is_fmt = true
 	if foptions.is_verbose {
 		eprintln('vfmt2 running fmt.fmt over file: $file')
 	}
diff --git a/vlib/v/ast/str.v b/vlib/v/ast/str.v
index 7e508309ec..b57df39a8c 100644
--- a/vlib/v/ast/str.v
+++ b/vlib/v/ast/str.v
@@ -107,7 +107,8 @@ pub fn (x &InfixExpr) str() string {
 }
 
 // Expressions in string interpolations may have to be put in braces if they
-// are non-trivial or if a format specification is given. In the latter case
+// are non-trivial, if they would interfere with the next character or if a
+// format specification is given. In the latter case
 // the format specifier must be appended, separated by a colon:
 // '$z $z.b $z.c.x ${x[4]} ${z:8.3f} ${a:-20} ${a>b+2}'
 // This method creates the format specifier (including the colon) or an empty
@@ -121,7 +122,7 @@ pub fn (lit &StringInterLiteral) get_fspec_braces(i int) (string, bool) {
 	if !needs_braces {
 		if i+1 < lit.vals.len && lit.vals[i+1].len > 0 {
 			next_char := lit.vals[i+1][0]
-			if util.is_func_char(next_char) || next_char == `.` {
+			if util.is_func_char(next_char) || next_char == `.` || next_char == `(` {
 				needs_braces = true
 			}
 		}
@@ -131,6 +132,15 @@ pub fn (lit &StringInterLiteral) get_fspec_braces(i int) (string, bool) {
 		for {
 			match sub_expr as sx {
 				Ident {
+					if sx.name[0] == `@` {
+						needs_braces = true
+					}
+					break
+				}
+				CallExpr {
+					if sx.args.len != 0 {
+						needs_braces = true
+					}
 					break
 				}
 				SelectorExpr {
diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index 3b43a53dbf..cda90819bd 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -5,7 +5,6 @@ module fmt
 
 import v.ast
 import v.table
-import v.util
 import strings
 
 const (
@@ -29,6 +28,7 @@ pub mut:
 	file              ast.File
 	did_imports       bool
 	is_assign         bool
+	is_inside_interp  bool
 	auto_imports      []string // automatically inserted imports that the user forgot to specify
 	import_pos        int // position of the imports in the resulting string for later autoimports insertion
 	used_imports      []string // to remove unused imports
@@ -619,8 +619,12 @@ pub fn (mut f Fmt) expr(node ast.Expr) {
 		}
 		ast.InfixExpr {
 			f.expr(it.left)
-			f.write(' $it.op.str() ')
-			f.wrap_long_line()
+			if f.is_inside_interp {
+				f.write('$it.op.str()')
+			} else {
+				f.write(' $it.op.str() ')
+				f.wrap_long_line()
+			}
 			f.expr(it.right)
 		}
 		ast.IndexExpr {
@@ -717,7 +721,19 @@ pub fn (mut f Fmt) expr(node ast.Expr) {
 		}
 		ast.StringInterLiteral {
 			// TODO: this code is very similar to ast.Expr.str()
-			f.write("'")
+			mut contains_single_quote := false
+			for val in it.vals {
+				if val.contains("'") {
+					contains_single_quote = true
+					break
+				}
+			}
+			if contains_single_quote {
+				f.write('"')
+			} else {
+				f.write("'")
+			}
+			f.is_inside_interp = true
 			for i, val in it.vals {
 				f.write(val)
 				if i >= it.exprs.len {
@@ -734,7 +750,12 @@ pub fn (mut f Fmt) expr(node ast.Expr) {
 					f.expr(it.exprs[i])
 				}
 			}
-			f.write("'")
+			f.is_inside_interp = false
+			if contains_single_quote {
+				f.write('"')
+			} else {
+				f.write("'")
+			}
 		}
 		ast.StructInit {
 			f.struct_init(it)
@@ -782,7 +803,11 @@ pub fn (mut f Fmt) call_args(args []ast.CallArg) {
 		}
 		f.expr(arg.expr)
 		if i < args.len - 1 {
-			f.write(', ')
+			if f.is_inside_interp {
+				f.write(',')
+			} else {
+				f.write(', ')
+			}
 		}
 	}
 }
diff --git a/vlib/v/fmt/fmt_keep_test.v b/vlib/v/fmt/fmt_keep_test.v
index 57f6dada68..2083d11373 100644
--- a/vlib/v/fmt/fmt_keep_test.v
+++ b/vlib/v/fmt/fmt_keep_test.v
@@ -44,8 +44,10 @@ fn test_fmt() {
 			continue
 		}
 		table := table.new_table()
-		file_ast := parser.parse_file(ipath, table, .parse_comments, &pref.Preferences{}, &ast.Scope{
-			parent: 0
+		file_ast := parser.parse_file(ipath, table, .parse_comments, &pref.Preferences{
+				is_fmt: true
+			}, &ast.Scope{
+				parent: 0
 		})
 		result_ocontent := fmt.fmt(file_ast, table, false)
 		if expected_ocontent != result_ocontent {
diff --git a/vlib/v/fmt/fmt_test.v b/vlib/v/fmt/fmt_test.v
index 3ccbcad3a8..32787c0702 100644
--- a/vlib/v/fmt/fmt_test.v
+++ b/vlib/v/fmt/fmt_test.v
@@ -44,8 +44,10 @@ fn test_fmt() {
 			continue
 		}
 		table := table.new_table()
-		file_ast := parser.parse_file(ipath, table, .parse_comments, &pref.Preferences{}, &ast.Scope{
-			parent: 0
+		file_ast := parser.parse_file(ipath, table, .parse_comments, &pref.Preferences{
+				is_fmt: true
+			}, &ast.Scope{
+				parent: 0
 		})
 		result_ocontent := fmt.fmt(file_ast, table, false)
 		if expected_ocontent != result_ocontent {
diff --git a/vlib/v/fmt/fmt_vlib_test.v b/vlib/v/fmt/fmt_vlib_test.v
index 5610da8faf..8c50442c3b 100644
--- a/vlib/v/fmt/fmt_vlib_test.v
+++ b/vlib/v/fmt/fmt_vlib_test.v
@@ -43,8 +43,10 @@ fn test_vlib_fmt() {
 			continue
 		}
 		table := table.new_table()
-		file_ast := parser.parse_file(ipath, table, .parse_comments, &pref.Preferences{}, &ast.Scope{
-			parent: 0
+		file_ast := parser.parse_file(ipath, table, .parse_comments, &pref.Preferences{
+				is_fmt: true
+			}, &ast.Scope{
+				parent: 0
 		})
 		result_ocontent := fmt.fmt(file_ast, table, false)
 		if expected_ocontent != result_ocontent {
diff --git a/vlib/v/fmt/tests/string_interpolation_expected.vv b/vlib/v/fmt/tests/string_interpolation_expected.vv
index 8f0ebdca52..9855d2edca 100644
--- a/vlib/v/fmt/tests/string_interpolation_expected.vv
+++ b/vlib/v/fmt/tests/string_interpolation_expected.vv
@@ -10,6 +10,14 @@ struct Cc {
 	a []Aa
 }
 
+fn (c &Cc) f() int {
+	return c.a[0].xy
+}
+
+fn (c &Cc) g(k, l int) int {
+	return c.a[k].xy + l
+}
+
 fn main() {
 	st := Bb{Aa{5}}
 	ar := Cc{[Aa{3}, Aa{-4}, Aa{12}]}
@@ -19,4 +27,6 @@ fn main() {
 	println('$st.a.xy${ar.a[2].xy}$aa.xy$z')
 	println('${st.a.xy}ya ${ar.a[2].xy}X2 ${aa.xy}.b ${z}3')
 	println('${z:-5} ${z:+5.3} ${z:+09.3f} ${z:-7.2} ${z:+09} ${z:08.3f}')
+	println('$ar.f() ${ar.g(1,2)} ${ar.a}() ${z}(')
+	println('${z>12.3*z-3} ${@VEXE} ${4*5}')
 }
diff --git a/vlib/v/fmt/tests/string_interpolation_input.vv b/vlib/v/fmt/tests/string_interpolation_input.vv
index 9c54e8dea4..31b109d7ed 100644
--- a/vlib/v/fmt/tests/string_interpolation_input.vv
+++ b/vlib/v/fmt/tests/string_interpolation_input.vv
@@ -10,6 +10,14 @@ struct Cc {
 	a []Aa
 }
 
+fn (c &Cc) f() int {
+	return c.a[0].xy
+}
+
+fn (c &Cc) g(k, l int) int {
+	return c.a[k].xy+l
+}
+
 fn main() {
 	st := Bb{Aa{5}}
 	ar := Cc{[Aa{3}, Aa{-4}, Aa{12}]}
@@ -19,4 +27,6 @@ fn main() {
 	println('${st.a.xy}${ar.a[2].xy}${aa.xy}${z}')
 	println('${st.a.xy}ya ${ar.a[2].xy}X2 ${aa.xy}.b ${z}3')
 	println('${z:-5} ${z:+5.3} ${z:+09.3f} ${z:-07.2} ${z:+009} ${z:008.3f}')
+	println('${ar.f()} ${ar.g(1, 2)} ${ar.a}() ${z}(')
+	println('${z > 12.3 * z - 3} ${@VEXE} ${4 * 5}')
 }
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index a4a81d7b58..1d9405d729 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -60,7 +60,7 @@ mut:
 
 // for tests
 pub fn parse_stmt(text string, table &table.Table, scope &ast.Scope) ast.Stmt {
-	s := scanner.new_scanner(text, .skip_comments)
+	s := scanner.new_scanner(text, .skip_comments, false)
 	mut p := Parser{
 		scanner: s
 		table: table
@@ -77,7 +77,7 @@ 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)
+	s := scanner.new_scanner(text, .skip_comments, pref.is_fmt)
 	mut p := Parser{
 		scanner: s
 		table: b_table
@@ -100,7 +100,7 @@ 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)
+		scanner: scanner.new_scanner_file(path, comments_mode, pref.is_fmt)
 		comments_mode: comments_mode
 		table: b_table
 		file_name: path
diff --git a/vlib/v/scanner/scanner.v b/vlib/v/scanner/scanner.v
index aa72459d6d..3cd4163e8d 100644
--- a/vlib/v/scanner/scanner.v
+++ b/vlib/v/scanner/scanner.v
@@ -94,7 +94,7 @@ pub enum CommentsMode {
 }
 
 // new scanner from file.
-pub fn new_scanner_file(file_path string, comments_mode CommentsMode) &Scanner {
+pub fn new_scanner_file(file_path string, comments_mode CommentsMode, is_fmt bool) &Scanner {
 	if !os.exists(file_path) {
 		verror("$file_path doesn't exist")
 	}
@@ -102,20 +102,20 @@ pub fn new_scanner_file(file_path string, comments_mode CommentsMode) &Scanner {
 		verror(err)
 		return voidptr(0)
 	}
-	mut s := new_scanner(raw_text, comments_mode) // .skip_comments)
+	mut s := new_scanner(raw_text, comments_mode, is_fmt) // .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) &Scanner {
+pub fn new_scanner(text string, comments_mode CommentsMode, is_fmt bool) &Scanner {
 	s := &Scanner{
 		text: text
 		is_print_line_on_error: true
 		is_print_colored_error: true
 		is_print_rel_paths_on_error: true
-		is_fmt: util.is_fmt()
+		is_fmt: is_fmt
 		comments_mode: comments_mode
 	}
 	return s
@@ -883,6 +883,9 @@ fn (mut s Scanner) text_scan() token.Token {
 		`@` {
 			s.pos++
 			name := s.ident_name()
+			if s.is_fmt {
+				return s.new_token(.name, '@' + name, name.len+1)
+			}
 			// @FN => will be substituted with the name of the current V function
 			// @MOD => will be substituted with the name of the current V module
 			// @STRUCT => will be substituted with the name of the current V struct
@@ -1204,14 +1207,14 @@ fn (mut s Scanner) ident_string() string {
 			s.error('0 character in a string literal')
 		}
 		// ${var} (ignore in vfmt mode)
-		if c == `{` && prevc == `$` && !is_raw && !s.is_fmt && s.count_symbol_before(s.pos - 2, slash) % 2 == 0 {
+		if c == `{` && prevc == `$` && !is_raw && s.count_symbol_before(s.pos - 2, slash) % 2 == 0 {
 			s.is_inside_string = true
 			// so that s.pos points to $ at the next step
 			s.pos -= 2
 			break
 		}
 		// $var
-		if util.is_name_char(c) && prevc == `$` && !s.is_fmt && !is_raw && s.count_symbol_before(s.pos - 2, slash) % 2 == 0 {
+		if util.is_name_char(c) && prevc == `$` && !is_raw && s.count_symbol_before(s.pos - 2, slash) % 2 == 0 {
 			s.is_inside_string = true
 			s.is_inter_start = true
 			s.pos -= 2
diff --git a/vlib/v/scanner/scanner_test.v b/vlib/v/scanner/scanner_test.v
index 34dc113cee..1ecf25bc42 100644
--- a/vlib/v/scanner/scanner_test.v
+++ b/vlib/v/scanner/scanner_test.v
@@ -45,7 +45,7 @@ fn fn_name_mod_level_high_order(cb fn(int)) {
 }
 
 fn scan_kinds(text string) []token.Kind {
-	mut scanner := new_scanner(text, .skip_comments)
+	mut scanner := new_scanner(text, .skip_comments, false)
 	mut token_kinds := []token.Kind{}
 	for {
 		tok := scanner.scan()
diff --git a/vlib/v/util/scanning.v b/vlib/v/util/scanning.v
index 9fc7e7e39b..072f7145d0 100644
--- a/vlib/v/util/scanning.v
+++ b/vlib/v/util/scanning.v
@@ -1,7 +1,5 @@
 module util
 
-import os
-
 [inline]
 pub fn is_name_char(c byte) bool {
 	return (c >= `a` && c <= `z`) || (c >= `A` && c <= `Z`) || c == `_`
@@ -43,7 +41,3 @@ pub fn good_type_name(s string) bool {
 pub fn cescaped_path(s string) string {
 	return s.replace('\\', '\\\\')
 }
-
-pub fn is_fmt() bool {
-	return os.executable().contains('vfmt')
-}