simplify vfmt

vlib/compiler/fn.v

@@ -969,6 +969,7 @@ fn (p mut Parser) fn_call_args(f mut Fn) {
 				p.error('`$arg.name` is a mutable argument, you need to provide a variable to modify: `$f.name(... mut a...)`')
 			}
 			p.check(.key_mut)
+			p.fspace()
 			var_name := p.lit
 			v := p.find_var(var_name) or {
 				p.error('`$arg.name` is a mutable argument, you need to provide a variable to modify: `$f.name(... mut a...)`')

vlib/compiler/parser.v

@@ -73,7 +73,6 @@ mut:
 	sql_params []string // ("select * from users where id = $1", ***"100"***)
 	sql_types []string // int, string and so on; see sql_params
 	is_vh bool // parsing .vh file (for example `const (a int)` is allowed)
-	fmt_dollar bool
 pub:
 	mod            string
 }

vlib/compiler/scanner.v

@@ -42,6 +42,8 @@ mut:
 	line_ends   []int // the positions of source lines ends   (i.e. \n signs)
 	nlines int  // total number of lines in the source file that were scanned
 	is_vh bool // Keep newlines
+	is_fmt bool // Used only for skipping ${} in strings, since we need literal
+	            // string values when generating formatted code.
 }
 
 // new scanner from file.
@@ -67,6 +69,7 @@ fn new_scanner_file(file_path string) &Scanner {
 	}
 
 	mut s := new_scanner(raw_text)
+	s.init_fmt()
 	s.file_path = file_path
 
 	return s
@@ -688,14 +691,14 @@ fn (s mut Scanner) ident_string() string {
 			s.error('0 character in a string literal')
 		}
 		// ${var}
-		if c == `{` && prevc == `$` && !is_raw && s.count_symbol_before(s.pos-2, slash) % 2 == 0 {
+		if c == `{` && prevc == `$` && !is_raw && !s.is_fmt && s.count_symbol_before(s.pos-2, slash) % 2 == 0 {
 			s.inside_string = true
 			// so that s.pos points to $ at the next step
 			s.pos -= 2
 			break
 		}
 		// $var
-		if (c.is_letter() || c == `_`) && prevc == `$` && !is_raw && s.count_symbol_before(s.pos-2, slash) % 2 == 0 {
+		if (c.is_letter() || c == `_`) && prevc == `$` && !s.is_fmt && !is_raw && s.count_symbol_before(s.pos-2, slash) % 2 == 0 {
 			s.inside_string = true
 			s.inter_start = true
 			s.pos -= 2

vlib/compiler/token.v

@@ -290,6 +290,9 @@ fn (t Token) str() string {
 		return t.lit
 		
 	}	
+	if t.tok == .chartoken {
+		return '`$t.lit`'
+	}	
 	if t.tok == .str {
 		return "'$t.lit'"
 	}	

vlib/compiler/vfmt.v

@@ -86,6 +86,11 @@ fn (p mut Parser) fmt_dec() {
 	p.scanner.fmt_indent--
 }
 
+[if vfmt]
+fn (p mut Scanner) init_fmt() {
+	p.is_fmt = true
+}
+
 [if vfmt]
 fn (p mut Parser) fnext() {
 	if p.tok == .eof {
@@ -95,18 +100,6 @@ fn (p mut Parser) fnext() {
 		p.fmt_dec()
 	}
 	mut s := p.strtok()
-	// Need to reconstruct an interpolated string from multiple string and
-	// dollar tokens.
-	// 'abc $name zxc' => ['abc', $, name, 'zxc'] => 'abc'$name'zxc'
-	// need to remove the extra '
-	if p.tok == .str && p.peek() == .dollar {
-		s = s[..s.len - 1]
-		p.fmt_dollar = true
-	}	
-	else if p.tok == .str && p.fmt_dollar {
-		s = s[1..]
-		p.fmt_dollar = false
-	}	
 	p.fgen(s)
 	// vfmt: increase indentation on `{` unless it's `{}`
 	if p.tok == .lcbr && !p.inside_if_expr && p.peek() != .rcbr {