Revert "gen: scape string function in gen/str.v (#6452)"

This reverts commit 60fbcc37fc.

vlib/builtin/string_test.v

@@ -619,7 +619,7 @@ fn test_for_loop_two() {
 
 fn test_quote() {
 	a := `'`
-	println("testing double quotes \"")
+	println("testing double quotes")
 	b := "hi"
 	assert b == 'hi'
 	assert a.str() == '\''

vlib/v/gen/str.v

@@ -5,97 +5,6 @@ module gen
 import v.ast
 import v.table
 
-fn smart_quote(str string, raw bool) string {
-	len := str.len
-	if len == 0 {
-		return str
-	}
-	mut result := ''
-	mut pos := -1
-	mut last := ''
-	mut next := ''
-	mut skip_next := false
-	for {
-		pos = pos + 1
-		if skip_next {
-			skip_next = false
-			pos = pos + 1
-		}
-		if pos >= len {
-			break
-		}
-		if pos + 1 < len {
-			unsafe {
-				next = str.str[pos + 1].str()
-			}
-		}
-		mut current := str
-		mut toadd := str
-		if len > 1 {
-			unsafe {
-				current = str.str[pos].str()
-			}
-			toadd = current
-		}
-		// double quote
-		if current == '"' {
-			toadd = '\\"'
-			current = ''
-		}
-		if raw && current == '\\' {
-			toadd = '\\\\'
-		}
-		// keep newlines in string
-		if current == '\n' {
-			toadd = '\\n'
-			current = ''
-		}
-		if current == '\r' && next == '\n' {
-			toadd = '\r\n'
-			current = ''
-			skip_next = true
-		}
-		// backslash
-		if !raw && current == '\\' {
-			// escaped backslash - keep as is
-			if next == '\\' {
-				toadd = '\\\\'
-				skip_next = true
-			}
-			// keep raw escape squence
-			else {
-				if next != '' {
-					if raw {
-						toadd = '\\\\' + next
-						skip_next = true
-					}
-					// escape it
-					else {
-						toadd = '\\' + next
-						skip_next = true
-					}
-				}
-			}
-		}
-		// Dolar sign
-		if !raw && current == '$' {
-			if last == '\\' {
-				toadd = '\\$'
-			}
-		}
-		// Windows style new line \r\n
-		if !raw && current == '\r' {
-			if next == '\n' {
-				skip_next = true
-				toadd = '\\n'
-			}
-		}
-		result = result + toadd
-		last = current
-	}
-	return result
-}
-
 fn (mut g Gen) write_str_fn_definitions() {
 	// _STR function can't be defined in vlib
 	g.writeln("
@@ -209,11 +118,11 @@ string _STR_TMP(const char *fmt, ...) {
 
 fn (mut g Gen) string_literal(node ast.StringLiteral) {
 	if node.is_raw {
-		escaped_val := smart_quote(node.val, true)
+		escaped_val := node.val.replace_each(['"', '\\"', '\\', '\\\\'])
 		g.write('tos_lit("$escaped_val")')
 		return
 	}
-	escaped_val := smart_quote(node.val, false)
+	escaped_val := node.val.replace_each(['"', '\\"', '\r\n', '\\n', '\n', '\\n'])
 	if g.is_c_call || node.language == .c {
 		// In C calls we have to generate C strings
 		// `C.printf("hi")` => `printf("hi");`
@@ -240,7 +149,7 @@ fn (mut g Gen) string_inter_literal_sb_optimized(call_expr ast.CallExpr) {
 	is_nl := call_expr.name == 'writeln'
 	// println('optimize sb $call_expr.name')
 	for i, val in node.vals {
-		escaped_val := smart_quote(val, false)
+		escaped_val := val.replace_each(['"', '\\"', '\r\n', '\\n', '\n', '\\n', '%', '%%'])
 		// if val == '' {
 		// break
 		// continue
@@ -311,8 +220,7 @@ fn (mut g Gen) string_inter_literal(node ast.StringInterLiteral) {
 	// Build the string with %
 	mut end_string := false
 	for i, val in node.vals {
-		mut escaped_val := val.replace_each(['%', '%%'])
+		escaped_val := val.replace_each(['"', '\\"', '\r\n', '\\n', '\n', '\\n', '%', '%%'])
-		escaped_val = smart_quote(escaped_val, false)
 		if i >= node.exprs.len {
 			if escaped_val.len > 0 {
 				end_string = true