allow nested text expressions

packages/moon/dist/moon.js

@@ -366,13 +366,23 @@
 			} else if (_char === "{") {
 				// If a sequence of characters begins with "{", process it as an
 				// expression token.
-				var expression = ""; // Consume the input until the end of the expression.
+				var expression = ""; // Keep a stack of opened objects.
+
+				var opened = 0; // Consume the input until the end of the expression.
 
 				for (i += 1; i < input.length; i++) {
 					var _char2 = input[i];
 
-					if (_char2 === "}") {
-						break;
+					if (_char2 === "{") {
+						opened += 1;
+						expression += _char2;
+					} else if (_char2 === "}") {
+						if (opened === 0) {
+							break;
+						} else {
+							opened -= 1;
+							expression += _char2;
+						}
 					} else {
 						expression += _char2;
 					}

packages/moon/src/compiler/lexer/lexer.js

@@ -313,12 +313,23 @@ export function lex(input) {
 			// expression token.
 			let expression = "";
 
+			// Keep a stack of opened objects.
+			let opened = 0;
+
 			// Consume the input until the end of the expression.
 			for (i += 1; i < input.length; i++) {
 				const char = input[i];
 
-				if (char === "}") {
-					break;
+				if (char === "{") {
+					opened += 1;
+					expression += char;
+				} else if (char === "}") {
+					if (opened === 0) {
+						break;
+					} else {
+						opened -= 1;
+						expression += char;
+					}
 				} else {
 					expression += char;
 				}

packages/moon/test/compiler/lexer.test.js

@@ -43,7 +43,7 @@ test("lex text inside tag", () => {
 })
 
 test("lex expression", () => {
-	expect(lex(`{data + 1}`)).toEqual([{"attributes": {"": {"value": "data.data + 1", isStatic: false}}, "closed": true, "type": "tagOpen", "value": "text"}]);
+	expect(lex(`{data + 1 + {foo: true, bar: false}}`)).toEqual([{"attributes": {"": {"value": "data.data + 1 + {foo: true, bar: false}", isStatic: false}}, "closed": true, "type": "tagOpen", "value": "text"}]);
 });
 
 test("lex attributes", () => {