Splitting a vector into two vectors based on some criterion

code review
1

There's probably a more elegant way to do this. I have a queue (crossbeam_channel) of these things:

/// Queue item sent to the the render land queue.
pub enum RenderHeightQueueItem {
    /// Update to this region's land height map.
    ApplyPatch(RenderHeightMap),
    /// Region with this region box wants to be told about edges.
    RequestEdge(RegionBox)
}

When processing the queue, I need to process all of one type in the enum before processing the other type. So I need to split the vector into two vectors, based on enum type. Here's the obvious solution, with a for loop and push calls. Is there a cleaner way to do a split like this?

                let requests: Vec<RenderHeightQueueItem> = land_queue_receiver.try_iter().collect();
                //  Separate patch requests from edge requests.
                let mut patches = Vec::new();
                let mut edge_requests = Vec::new();
                for request in requests {
                    match request {
                        RenderHeightQueueItem::ApplyPatch(patch) => patches.push(patch),
                        RenderHeightQueueItem::RequestEdge(region_box) => edge_requests.push(region_box),
                    }
                }
                //  Handle patches first.
                if !patches.is_empty() {
                    self.combine_height_maps(&height_mesh, patches, scene_link, land_object_link);
                }
                //  Then edge requests.
                for region_box in edge_requests {
                    self.handle_edge_request(region_box);
                }

Use case: this is part of a metaverse client. The server is sending land patches, providing elevation data for a small area. Those have to be assembled into a height map, from which a mesh is generated and drawn. There are multiple big land squares with edges in common, and when a new square goes live, it needs edge info for adjacent squares.

2

I think the for loop is fine, but Itertools::partition_map can also do this.

1 Like
3

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