Merge pull request #4 from aka-l/newstructure

i like your proposal for a new structure. go one.

Author: a3ka

packages/core/src/core/DataFrame.js

@@ -0,0 +1,108 @@
+// src/core/DataFrame.js
+
+import { createFrame } from './createFrame.js';
+import { extendDataFrame } from '../methods/autoExtend.js';
+
+/**
+ * @typedef {Object} TinyFrame
+ * @property {Record<string, Float64Array | Int32Array>} columns - Columns of the frame
+ */
+
+/**
+ * DataFrame — chainable API wrapper for TinyFrame structure.
+ * Provides convenient access to columns, row count, and conversion to array of objects.
+ */
+export class DataFrame {
+  /**
+   * Main constructor.
+   * @param {TinyFrame} frame - The underlying TinyFrame data structure
+   * @throws {Error} If frame is not a valid TinyFrame
+   */
+  constructor(frame) {
+    if (!frame || typeof frame !== 'object' || !frame.columns) {
+      throw new Error('Invalid TinyFrame passed to DataFrame');
+    }
+    this._frame = frame;
+  }
+
+  /**
+   * Factory method for creating a DataFrame from rows, columns, or another frame.
+   * @param {Object[]|Record<string, any[]>|TinyFrame} input
+   * @param {Object} [options]
+   * @returns {DataFrame}
+   */
+  static create(input, options = {}) {
+    const frame = createFrame(input, options);
+    return new DataFrame(frame);
+  }
+
+  /**
+   * Returns the list of column names.
+   * @returns {string[]}
+   */
+  get columns() {
+    return Object.keys(this._frame.columns);
+  }
+
+  /**
+   * Returns the number of rows in the DataFrame.
+   * @returns {number}
+   */
+  get rowCount() {
+    const first = Object.values(this._frame.columns)[0];
+    return first?.length || 0;
+  }
+
+  /**
+   * Converts the DataFrame to an array of plain JavaScript objects (row-wise).
+   * @returns {Array<Object>} Array of row objects
+   */
+  toArray() {
+    const result = [];
+    const keys = this.columns;
+    const len = this.rowCount;
+
+    for (let i = 0; i < len; i++) {
+      const row = {};
+      for (const key of keys) {
+        row[key] = this._frame.columns[key][i];
+      }
+      result.push(row);
+    }
+    return result;
+  }
+
+  /**
+   * Returns the underlying TinyFrame data structure.
+   * @returns {TinyFrame}
+   */
+  get frame() {
+    return this._frame;
+  }
+
+  /**
+   * Handles the result of a DataFrame operation, checking if it should be printed
+   * based on metadata
+   *
+   * @param {DataFrame} result - The DataFrame result to handle
+   * @returns {DataFrame} The same DataFrame result
+   * @private
+   */
+  _handleResult(result) {
+    // Check if the result has metadata indicating it should be printed
+    if (
+      result &&
+      result._frame &&
+      result._frame._meta &&
+      result._frame._meta.shouldPrint
+    ) {
+      result.print();
+      // Clean up the metadata to avoid repeated printing
+      delete result._frame._meta.shouldPrint;
+    }
+    return result;
+  }
+}
+
+// Extend DataFrame with all methods from aggregation, filtering, etc.
+extendDataFrame(DataFrame);