Use plain text for reference solution (no ROT13)

README.md

@@ -21,7 +21,7 @@ Clicking it opens a chat panel on the right side and sends the following context
 - The **cell source code** and its **kernel language**
 - Any **error output** produced by the cell (traceback included)
 - **Preceding code cells and markdown cell** (up to the previous markdown cell), used as the exercise description
-- An optional **reference solution** and **evaluation criteria** stored in the cell metadata (the solution is ROT13-encoded to keep it hidden from students)
+- An optional **reference_solution** (multiline string) and **evaluation_criteria** (multiline string) stored in the cell metadata <!-- (the solution is ROT13-encoded to keep it hidden from students) -->
 
 The AI replies using a configurable **system prompt** (`TUTOR.md`) that shapes its pedagogical behavior. By default the extension looks for a `TUTOR.md` file walking up from the notebook's directory to the server root, so different courses or folders can each have their own tutor persona.
 

examples/matplotlib_exercices.ipynb

@@ -49,9 +49,8 @@
    "metadata": {
     "deletable": true,
     "editable": true,
-    "evaluation_criteria": "Typo Correction: Correct 'np.linsapce' typo to 'np.linspace'.\nPlot Output: Ensure the Sine and Cosine waves plot is correctly rendered without runtime errors."
-    ,
-    "reference_solution": "vzcbeg zngcybgyvo.clcybg nf cyg\nvzcbeg ahzcl nf ac\nk = ac.yvafcnpr(0, 2 * ac.cv, 100)\nsvt, nk = cyg.fhocybgf(svtfvmr=(8, 4))\nnk.cybg(k, ac.fva(k), ynory='fva(k)', pbybe='eblnyoyhr')\nnk.cybg(k, ac.pbf(k), ynory='pbf(k)', pbybe='gbzngb', yvarfglyr='--')\nnk.frg_gvgyr('Fvar naq Pbfvar Jnirf')\nnk.frg_kynory('k')\nnk.frg_lynory('l')\nnk.yrtraq()\nnk.tevq(Gehr, nycun=0.3)\ncyg.gvtug_ynlbhg()\ncyg.fubj()",
+    "evaluation_criteria": "Typo Correction: Correct 'np.linsapce' typo to 'np.linspace'.\nPlot Output: Ensure the Sine and Cosine waves plot is correctly rendered without runtime errors.",
+    "reference_solution": "import matplotlib.pyplot as plt\nimport numpy as np\nx = np.linspace(0, 2 * np.pi, 100)\nfig, ax = plt.subplots(figsize=(8, 4))\nax.plot(x, np.sin(x), label='sin(x)', color='royalblue')\nax.plot(x, np.cos(x), label='cos(x)', color='tomato', linestyle='--')\nax.set_title('Sine and Cosine Waves')\nax.set_xlabel('x')\nax.set_ylabel('y')\nax.legend()\nax.grid(True, alpha=0.3)\nplt.tight_layout()\nplt.show()",
     "slideshow": {
      "slide_type": ""
     },
@@ -100,7 +99,7 @@
     "deletable": true,
     "editable": true,
     "evaluation_criteria": "Bar chart creation: Uses ax.bar with categories and values.\nAesthetics & Colors: Applies a different color to each bar.\nValue Labels: Correctly loops over the bars to add text scores above each bar.",
-    "reference_solution": "pngrtbevrf = ['Clguba', 'WninFpevcg', 'Ehfg', 'Tb', 'Whyvn']\ninyhrf = [85, 72, 58, 45, 30]\nsvt, nk = cyg.fhocybgf(svtfvmr=(8, 4))\npbybef = ['eblnyoyhr', 'gbzngb', 'zrqvhzfrnterra', 'benatr', 'zrqvhzchecyr']\nonef = nk.one(pngrtbevrf, inyhrf, pbybe=pbybef)\nnk.frg_gvgyr('Cebtenzzvat Ynathntr Fpberf')\nnk.frg_lynory('Fpber')\nsbe one va onef:\n    liny = one.trg_urvtug()\n    nk.grkg(one.trg_k() + one.trg_jvqgu()/2.0, liny + 1, fge(liny), un='pragre', in='obggbz')\ncyg.gvtug_ynlbhg()\ncyg.fubj()",
+    "reference_solution": "categories = ['Python', 'JavaScript', 'Rust', 'Go', 'Julia']\nvalues = [85, 72, 58, 45, 30]\nfig, ax = plt.subplots(figsize=(8, 4))\ncolors = ['royalblue', 'tomato', 'mediumseagreen', 'orange', 'mediumpurple']\nbars = ax.bar(categories, values, color=colors)\nax.set_title('Programming Language Scores')\nax.set_ylabel('Score')\nfor bar in bars:\n    yval = bar.get_height()\n    ax.text(bar.get_x() + bar.get_width()/2.0, yval + 1, str(yval), ha='center', va='bottom')\nplt.tight_layout()\nplt.show()",
     "slideshow": {
      "slide_type": ""
     },
@@ -158,7 +157,7 @@
     "deletable": true,
     "editable": true,
     "evaluation_criteria": "Random data seed: Fails to set random seed 42, generating incorrect data coordinates.\nColorbar & Labels: Missing colorbar, title, grid, or x/y labels on the axes.\nScatter aesthetic parameters: Fails to set alpha=0.6, colormap='viridis', size mapping, or color mapping.",
-    "reference_solution": "ac.enaqbz.frrq(42)\na = 150\nk = ac.enaqbz.enaqa(a)\nl = ac.enaqbz.enaqa(a)\nfvmrf = ac.enaqbz.havsbez(20, 200, a)\npbybef = ac.enaqbz.enaq(a)\nsvt, nk = cyg.fhocybgf(svtfvmr=(8, 6))\nfpnggre = nk.fpnggre(k, l, p=pbybef, f=fvmrf, pznc='ivevqvf', nycun=0.6)\ncyg.pbybeone(fpnggre, nk=nk, ynory='Pbybe inyhr')\nnk.frg_gvgyr('Enaqbz Fpnggre Cybg')\nnk.frg_kynory('K inyhrf')\nnk.frg_lynory('L inyhrf')\nnk.tevq(Gehr, nycun=0.3)\ncyg.gvtug_ynlbhg()\ncyg.fubj()",
+    "reference_solution": "np.random.seed(42)\nn = 150\nx = np.random.randn(n)\ny = np.random.randn(n)\nsizes = np.random.uniform(20, 200, n)\ncolors = np.random.rand(n)\nfig, ax = plt.subplots(figsize=(8, 6))\nscatter = ax.scatter(x, y, c=colors, s=sizes, cmap='viridis', alpha=0.6)\nplt.colorbar(scatter, ax=ax, label='Color value')\nax.set_title('Random Scatter Plot')\nax.set_xlabel('X values')\nax.set_ylabel('Y values')\nax.grid(True, alpha=0.3)\nplt.tight_layout()\nplt.show()",
     "slideshow": {
      "slide_type": ""
     },

src/index.ts

@@ -19,7 +19,7 @@ import { infoIcon } from '@jupyterlab/ui-components';
 
 import { clearItem, stopItem } from './components';
 import { TUTOR_USER, TutorChatModel } from './model';
-import { decodeRot13, isContinuous } from './utils';
+import { decodeSolution, isContinuous } from './utils';
 
 const INFO_ICON_BASE_64 = btoa(infoIcon.svgstr);
 
@@ -279,7 +279,7 @@ const plugin: JupyterFrontEndPlugin<void> = {
         // Retrieve and decode reference_solution from metadata
         const rawSolution = cell.model.getMetadata('reference_solution');
         const referenceSolution =
-          typeof rawSolution === 'string' ? decodeRot13(rawSolution) : '';
+          typeof rawSolution === 'string' ? decodeSolution(rawSolution) : '';
 
         // Retrieve evaluation_criteria from metadata
         const evaluationCriteria = cell.model.getMetadata(

src/utils.ts

@@ -13,11 +13,14 @@ export function isContinuous(numbers: number[]): boolean {
 }
 
 /**
- * Decodes a ROT13 encoded string.
+ * Decodes the reference solution.
+ * No-op for now, but could be a ROT13 decoder.
  */
-export function decodeRot13(str: string): string {
-  return str.replace(/[a-zA-Z]/g, c => {
-    const base = c <= 'Z' ? 65 : 97;
-    return String.fromCharCode(((c.charCodeAt(0) - base + 13) % 26) + base);
-  });
+export function decodeSolution(str: string): string {
+  /* TODO: switch to a ROT13 encoded solution ? */
+  // return str.replace(/[a-zA-Z]/g, c => {
+  //   const base = c <= 'Z' ? 65 : 97;
+  //   return String.fromCharCode(((c.charCodeAt(0) - base + 13) % 26) + base);
+  // });
+  return str;
 }