feat(playground): execute code pasted in url

Author: singaraiona

README.md

@@ -170,6 +170,44 @@ rayforce-wasm/
 └── examples/             # Usage examples
 ```
 
+## Zulip Code Playground Integration
+
+The playground supports URL query parameters for integration with [Zulip's code playgrounds](https://zulip.com/help/code-blocks#code-playgrounds) feature.
+
+### URL Format
+
+```
+https://your-playground-url/?code=<URL-encoded-expression>
+```
+
+### Setting up in Zulip
+
+1. Go to **Organization settings** → **Code playgrounds**
+2. Add a new playground:
+   - **Language**: `rayfall` (or `rayforce`, `lisp`)
+   - **Name**: `RayforceDB Playground`
+   - **URL template**: `https://rayforcedb.github.io/rayforce-wasm/?code={code}`
+
+### Example
+
+When a user writes a code block like:
+
+````markdown
+```rayfall
+(sum (til 100))
+```
+````
+
+Clicking the playground button will open the RayforceDB WASM playground and automatically execute the expression.
+
+### Multi-line Code
+
+The playground handles multi-line code by executing each line sequentially:
+
+```
+https://playground-url/?code=(def%20x%2010)%0A(sum%20(til%20x))
+```
+
 ## Performance Notes
 
 - Built with `-O3` and `-msimd128` for SIMD acceleration

examples/index.html

@@ -727,7 +727,10 @@ <h2>Try these examples</h2>
 
                 input.disabled = false;
                 input.focus();
-                
+
+                // Execute any code passed via URL (Zulip code playground)
+                executeUrlCode();
+
             } catch (err) {
                 setStatus('error', 'Failed to load');
                 log(`Error: ${err.message}`, 'error');
@@ -773,7 +776,29 @@ <h2>Try these examples</h2>
                 }
             });
         });
-        
+
+        // Parse URL query parameters for Zulip code playground integration
+        function getCodeFromUrl() {
+            const params = new URLSearchParams(window.location.search);
+            return params.get('code');
+        }
+
+        // Execute code from URL after initialization
+        function executeUrlCode() {
+            const code = getCodeFromUrl();
+            if (code && rayforce) {
+                log('Executing code from URL...', 'system');
+                // Handle multi-line code (newlines may be encoded)
+                const lines = code.split('\n');
+                for (const line of lines) {
+                    const trimmed = line.trim();
+                    if (trimmed) {
+                        evaluate(trimmed);
+                    }
+                }
+            }
+        }
+
         // Initialize
         initRayforce();
     </script>