parser: add custom parser to handle props statement

Author: zackad

src/melody/melody-extension-core/index.js

@@ -31,6 +31,7 @@ import { SetParser } from "./parser/set.js";
 import { SpacelessParser } from "./parser/spaceless.js";
 import { UseParser } from "./parser/use.js";
 import { MountParser } from "./parser/mount.js";
+import { PropsParser } from "./parser/props.js";
 
 import forVisitor from "./visitors/for.js";
 import testVisitor from "./visitors/tests.js";
@@ -97,7 +98,8 @@ export const extension = {
         SetParser,
         SpacelessParser,
         UseParser,
-        MountParser
+        MountParser,
+        PropsParser
     ],
     unaryOperators,
     binaryOperators,

src/melody/melody-extension-core/parser/props.js

@@ -0,0 +1,37 @@
+import { DoStatement, PropItem, PropsStatement } from "../types.js";
+import {
+    createNode,
+    setEndFromToken,
+    setStartFromToken,
+    Types
+} from "../../melody-parser/index.js";
+import { Identifier } from "../../melody-types/index.js";
+
+export const PropsParser = {
+    name: "props",
+    parse(parser, token) {
+        const tokenStream = parser.tokens;
+        const items = [];
+        let name;
+        let nameNode;
+        let valueNode;
+
+        do {
+            name = tokenStream.expect(Types.SYMBOL);
+            nameNode = createNode(Identifier, name, name.text);
+            if (tokenStream.test(Types.ASSIGNMENT)) {
+                tokenStream.expect(Types.ASSIGNMENT);
+                valueNode = parser.matchExpression();
+            } else {
+                valueNode = undefined;
+            }
+            const item = new PropItem(nameNode, valueNode);
+            items.push(item);
+        } while (tokenStream.nextIf(Types.COMMA));
+
+        const propsStatement = new PropsStatement(items);
+        setStartFromToken(propsStatement, token);
+        setEndFromToken(propsStatement, tokenStream.expect(Types.TAG_END));
+        return propsStatement;
+    }
+};