block based eval

packages/codemirror/block_utilities.mjs

@@ -0,0 +1,51 @@
+// Block-based evaluation utilities
+
+export function getBlockRegions(code) {
+  const chars = code.split('');
+  let i = 0,
+    blanks = [],
+    blockStart = 0,
+    regions = [];
+  while (i < chars.length) {
+    const isBlank = chars[i] === '\n';
+    if (isBlank) {
+      blanks.push(i);
+    } else if (chars[i].trim() !== '') {
+      if (blanks.length > 1) {
+        regions.push([blockStart, blanks[0]]);
+        blockStart = i;
+      }
+      blanks = [];
+    }
+    i++;
+  }
+  regions.push([blockStart, blanks.length ? blanks[0] : i]);
+  return regions;
+}
+
+export function getBlockAt(code, cursor) {
+  const regions = getBlockRegions(code);
+  for (const [start, end] of regions) {
+    if (cursor >= start && cursor <= end) {
+      return [start, end];
+    }
+  }
+  return null;
+}
+
+export const evalBlock = (strudelMirror) => {
+  const { state } = strudelMirror.editor;
+  const code = state.doc.toString();
+  const cursor = state.selection.main.head;
+  const range = getBlockAt(code, cursor);
+  if (range) {
+    const [a, b] = range;
+    const block = code.slice(a, b);
+    if (block) {
+      // Flash the block being evaluated
+      strudelMirror.flash(200, { from: a, to: b });
+      strudelMirror.repl.evaluate(block, true, true, true, { range });
+    }
+  }
+  return true;
+};