Variables: one engine for server and client, and spans for live editors

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Backend/Main.py

@@ -87,7 +87,7 @@ from Users import (
     UserColourOptions,
     VerifyLogin,
 )
-from VarFunctions import ResolvePortals
+from VarFunctions import ResolvePortals, ResolveSpans
 from pydantic import BaseModel
 
 
@@ -614,6 +614,23 @@ def GetFileEndpoint(
     return StreamBinaryFile(FilePath, request.headers.get("range"))
 
 
+class SpansRequest(BaseModel):
+    Content: str
+
+
+# Where each variable is in the text being edited, and what it resolves to
+# (VarEngine.ResolveSpans): the live editors show the results in place.
+@Application.post("/api/file/spans")
+def PostFileSpansEndpoint(
+    Root: str, Path: str, Body: SpansRequest, CurrentUser: dict = Depends(GetCurrentUserOrGuest)
+) -> dict:
+    RequirePathAccessible(Root, Path, CurrentUser)
+    if len(Body.Content) > 2_000_000:
+        raise HTTPException(status_code=413, detail="Too long to resolve.")
+    Spans = ResolveSpans(Root, Path, Body.Content, CurrentUser["Username"], CurrentUser.get("Groups", []))
+    return {"Spans": Spans}
+
+
 @Application.get("/api/file/resolved")
 def GetResolvedFileEndpoint(
     Root: str, Path: str, CurrentUser: dict = Depends(GetCurrentUserOrGuest)