string: make replace() clone for now; parser: comptime method

vlib/builtin/string.v

@@ -156,7 +156,7 @@ pub fn (s string) replace_once(rep, with string) string {
 
 pub fn (s string) replace(rep, with string) string {
 	if s.len == 0 || rep.len == 0 {
-		return s
+		return s.clone()
 	}
 	// TODO PERF Allocating ints is expensive. Should be a stack array
 	// Get locations of all reps within this string
@@ -172,7 +172,7 @@ pub fn (s string) replace(rep, with string) string {
 	}
 	// Dont change the string if there's nothing to replace
 	if idxs.len == 0 {
-		return s
+		return s.clone()
 	}
 	// Now we know the number of replacements we need to do and we can calc the len of the new string
 	new_len := s.len + idxs.len * (with.len - rep.len)

vlib/v/gen/cgen.v

@@ -1158,9 +1158,17 @@ fn (g &Gen) autofree_variable(v ast.Var) string {
 			else {
 				// NOTE/TODO: assign_stmt multi returns variables have no expr
 				// since the type comes from the called fns return type
+				/*
+				f := v.name[0]
+				if
+					//!(f >= `a` && f <= `d`) {
+					//f != `c` {
+					v.name!='cvar_name' {
 					t := typeof(v.expr)
 				return '// other ' + t + '\n'
 				}
+				*/
+			}
 		}
 		return g.autofree_var_call('string_free', v)
 	}

vlib/v/parser/comptime.v

@@ -6,6 +6,7 @@ module parser
 import v.ast
 import v.pref
 import v.vmod
+import v.table
 
 const (
 	supported_platforms = ['windows', 'mac', 'macos', 'darwin', 'linux', 'freebsd', 'openbsd',
@@ -189,3 +190,41 @@ fn os_from_string(os string) pref.OS {
 	// println('bad os $os') // todo panic?
 	return .linux
 }
+
+// `user.$method()` (`method` is a string)
+fn (mut p Parser) comptime_method_call(typ table.Type) {
+	p.check(.dollar)
+	method_name := p.check_name()
+	_ = method_name
+	mut j := 0
+	sym := p.table.get_type_symbol(typ)
+	if sym.kind != .struct_ {
+		p.error('not a struct')
+	}
+	// info := sym.info as table.Struct
+	for method in sym.methods {
+		if method.return_type != table.void_type {
+			continue
+		}
+		/*
+		receiver := method.args[0]
+		if !p.expr_var.ptr {
+			p.error('`$p.expr_var.name` needs to be a reference')
+		}
+		amp := if receiver.is_mut && !p.expr_var.ptr { '&' } else { '' }
+		if j > 0 {
+			p.gen(' else ')
+		}
+		p.genln('if (string_eq($method_name, _STR("$method.name")) ) ' + '${typ.name}_$method.name ($amp $p.expr_var.name);')
+		*/
+		j++
+	}
+	p.check(.lpar)
+	p.check(.rpar)
+	if p.tok.kind == .key_orelse {
+		p.check(.key_orelse)
+		// p.genln('else {')
+		p.check(.lcbr)
+		// p.statements()
+	}
+}