refactor: only expose subset of parser api

Author: DylanPiercey

src/__tests__/bench.ts

@@ -39,14 +39,14 @@ const COMPARE = process.env.COMPARE;
     const { createParser } = API;
     suite.add(entry, () => {
       const parser = createParser({});
-      parser.parse(src, filename);
+      parser.parse(src);
     });
 
     if (compareModule) {
       const { createParser } = compareModule;
       suite.add(`${entry} #${COMPARE}`, () => {
         const parser = createParser({});
-        parser.parse(src, filename);
+        parser.parse(src);
       });
     }
 

src/__tests__/main.test.ts

@@ -117,7 +117,7 @@ for (const entry of fs.readdirSync(FIXTURES)) {
         addValueRange(range.block ? `scriptlet:block` : `scriptlet`, range);
       },
     });
-    parser.parse(src, filename);
+    parser.parse(src);
 
     let result = "";
     for (let line = 0; line < partsByLine.length; line++) {

src/core/Parser.ts

@@ -32,7 +32,6 @@ export class Parser {
   public pos!: number;
   public maxPos!: number;
   public data!: string;
-  public filename!: string;
   public activeState!: StateDefinition;
   public activeRange!: Meta;
   public forward!: boolean;
@@ -47,16 +46,6 @@ export class Parser {
 
   constructor(public handlers: Handlers) {
     this.handlers = handlers;
-    this.reset();
-  }
-
-  reset() {
-    this.forward = this.isConcise = true;
-    this.pos = this.maxPos = this.textPos = -1;
-    this.data = this.filename = this.indent = "";
-    this.beginMixedMode = this.endingMixedModeAtEOL = false;
-    this.lines = this.activeTag = this.activeAttr = undefined;
-    this.enterState(STATE.CONCISE_HTML_CONTENT);
   }
 
   read(range: Range) {
@@ -291,16 +280,21 @@ export class Parser {
     this.pos += ahead;
   }
 
-  parse(data: string, filename: string) {
-    this.data = data;
-    this.filename = filename;
+  parse(data: string) {
     const maxPos = (this.maxPos = data.length);
+    this.data = data;
+    this.indent = "";
+    this.textPos = -1;
+    this.forward = this.isConcise = true;
+    this.beginMixedMode = this.endingMixedModeAtEOL = false;
+    this.lines = this.activeTag = this.activeAttr = undefined;
 
     // Skip the byte order mark (BOM) sequence
     // at the beginning of the file if there is one:
     // - https://en.wikipedia.org/wiki/Byte_order_mark
     // > The Unicode Standard permits the BOM in UTF-8, but does not require or recommend its use.
     this.pos = data.charCodeAt(0) === 0xfeff ? 1 : 0;
+    this.enterState(STATE.CONCISE_HTML_CONTENT);
 
     while (this.pos < maxPos) {
       const code = data.charCodeAt(this.pos);

src/index.ts

@@ -1,4 +1,4 @@
-import { type Handlers, Parser } from "./internal";
+import { type Handlers, type Range, Parser } from "./internal";
 export {
   OpenTagEnding,
   type Handlers,
@@ -8,6 +8,37 @@ export {
   type Range,
 } from "./internal";
 
+/**
+ * Creates a new Marko parser.
+ */
 export function createParser(handlers: Handlers) {
-  return new Parser(handlers);
+  // Expose a subset of the parser api.
+  const parser = new Parser(handlers);
+
+  return {
+    /**
+     * Parses code and calls the provided handlers.
+     */
+    parse(code: string) {
+      return parser.parse(code);
+    },
+    /**
+     * Given an offset range in the current source code, reads and returns the substring in the input code.
+     */
+    read(range: Range) {
+      return parser.read(range);
+    },
+    /**
+     * Given a offset in the current source code, returns a Position object with line & character information.
+     */
+    positionAt(index: number) {
+      return parser.positionAt(index);
+    },
+    /**
+     * Given a offset range in the current source code, returns a Location object with a start & end position information.
+     */
+    locationAt(range: Range) {
+      return parser.locationAt(range);
+    },
+  };
 }