issue #2 - fix template string scanning

now it correctly check first char of variable

node/scalar/t_encapsed_test.go

@@ -36,6 +36,29 @@ func TestSimpleVar(t *testing.T) {
 	assertEqual(t, expected, actual)
 }
 
+func TestSimpleVarOneChar(t *testing.T) {
+	src := `<? "test $a";`
+
+	expected := &stmt.StmtList{
+		Stmts: []node.Node{
+			&stmt.Expression{
+				Expr: &scalar.Encapsed{
+					Parts: []node.Node{
+						&scalar.EncapsedStringPart{Value: "test "},
+						&expr.Variable{VarName: &node.Identifier{Value: "a"}},
+					},
+				},
+			},
+		},
+	}
+
+	actual, _, _ := php7.Parse(bytes.NewBufferString(src), "test.php")
+	assertEqual(t, expected, actual)
+
+	actual, _, _ = php5.Parse(bytes.NewBufferString(src), "test.php")
+	assertEqual(t, expected, actual)
+}
+
 func TestSimpleVarEndsEcapsed(t *testing.T) {
 	src := `<? "test $var\"";`
 
@@ -60,6 +83,30 @@ func TestSimpleVarEndsEcapsed(t *testing.T) {
 	assertEqual(t, expected, actual)
 }
 
+func TestStringVarCurveOpen(t *testing.T) {
+	src := `<? "=$a{$b}";`
+
+	expected := &stmt.StmtList{
+		Stmts: []node.Node{
+			&stmt.Expression{
+				Expr: &scalar.Encapsed{
+					Parts: []node.Node{
+						&scalar.EncapsedStringPart{Value: "="},
+						&expr.Variable{VarName: &node.Identifier{Value: "a"}},
+						&expr.Variable{VarName: &node.Identifier{Value: "b"}},
+					},
+				},
+			},
+		},
+	}
+
+	actual, _, _ := php7.Parse(bytes.NewBufferString(src), "test.php")
+	assertEqual(t, expected, actual)
+
+	actual, _, _ = php5.Parse(bytes.NewBufferString(src), "test.php")
+	assertEqual(t, expected, actual)
+}
+
 func TestSimpleVarPropertyFetch(t *testing.T) {
 	src := `<? "test $foo->bar()";`
 

scanner/scanner.go

@@ -31,6 +31,10 @@ const (
 
 var heredocLabel []lex.Char
 
+func isValidFirstVarNameRune(r rune) bool {
+	return r >= 'A' && r <= 'Z' || r == '_' || r >= 'a' && r <= 'z' || r >= '\u007f' && r <= 'ÿ'
+}
+
 func (l *Lexer) Lex(lval Lval) int {
 	l.Comments = nil
 	c := l.Enter()
@@ -8627,7 +8631,7 @@ yyrule149: // .|[ \t\n\r]
 			switch l.Prev.Rune {
 			case '$':
 				c = l.Next()
-				if l.Prev.Rune == '{' || c >= 'A' && c <= 'Z' || c == '_' || c >= 'a' && c <= 'z' || c >= '\u007f' && c <= 'ÿ' {
+				if l.Prev.Rune == '{' || isValidFirstVarNameRune(l.Prev.Rune) {
 					l.ungetChars(2)
 					tb := l.Token()
 					lval.Token(l.newToken(tb[:len(tb)-2]))

scanner/scanner.l

@@ -30,6 +30,10 @@ const (
 
 var heredocLabel []lex.Char
 
+func isValidFirstVarNameRune(r rune) bool {
+    return r >= 'A' && r <= 'Z' || r == '_' || r >= 'a' && r <= 'z' || r >= '\u007f' && r <= 'ÿ'
+}
+
 func (l *Lexer) Lex(lval Lval) int {
     l.Comments = nil
     c := l.Enter()
@@ -451,7 +455,7 @@ NEW_LINE        (\r|\n|\r\n)
         switch l.Prev.Rune {
             case '$':
                 c = l.Next();
-                if l.Prev.Rune == '{' || c >= 'A' && c <= 'Z' || c == '_' || c >= 'a' && c <= 'z' || c >= '\u007f' && c <= 'ÿ' {
+                if l.Prev.Rune == '{' || isValidFirstVarNameRune(l.Prev.Rune) {
                     l.ungetChars(2)
                     tb := l.Token()
                     lval.Token(l.newToken(tb[:len(tb)-2]));

scanner/scanner_test.go

@@ -427,6 +427,10 @@ func TestTokens(t *testing.T) {
 
 func TestTeplateStringTokens(t *testing.T) {
 	src := `<?php
+		"foo $a"
+
+		"foo $a{$b}"
+
 		` + "`test $var {$var} ${var_name} {s $ \\$a `" + `
 
 		"test $var {$var} ${var_name} {s $ \$a "
@@ -435,6 +439,19 @@ func TestTeplateStringTokens(t *testing.T) {
 	`
 
 	expected := []int{
+		scanner.Rune2Class('"'),
+		scanner.T_ENCAPSED_AND_WHITESPACE,
+		scanner.T_VARIABLE,
+		scanner.Rune2Class('"'),
+
+		scanner.Rune2Class('"'),
+		scanner.T_ENCAPSED_AND_WHITESPACE,
+		scanner.T_VARIABLE,
+		scanner.T_CURLY_OPEN,
+		scanner.T_VARIABLE,
+		scanner.Rune2Class('}'),
+		scanner.Rune2Class('"'),
+
 		scanner.Rune2Class('`'),
 		scanner.T_ENCAPSED_AND_WHITESPACE,
 		scanner.T_VARIABLE,