Fix broken parsing case

decoder_test.go

@@ -21,6 +21,14 @@ func TestDecode_interface(t *testing.T) {
 				"bar": "${file(\"bing/bong.txt\")}",
 			},
 		},
+		{
+			"basic_squish.hcl",
+			false,
+			map[string]interface{}{
+				"foo": "bar",
+				"bar": "${file(\"bing/bong.txt\")}",
+			},
+		},
 		{
 			"empty.hcl",
 			false,

hcl/lex.go

@@ -170,7 +170,7 @@ func (x *hclLex) lexId(yylval *hclSymType) int {
 			break
 		}
 
-		if unicode.IsSpace(c) {
+		if !unicode.IsDigit(c) && !unicode.IsLetter(c) && c != '_' {
 			x.backup()
 			break
 		}

test-fixtures/basic_squish.hcl

@@ -0,0 +1,2 @@
+foo="bar"
+bar="${file("bing/bong.txt")}"