This crate contains the logic for evaluating the task graphs that are generated by vegafusion-core. Task graph evaluation involes:
- Compiling Vega expression ASTs to DataFusion expressions.
- Evaluating signal expression tasks
- Evaluating Data tasks, including transform pipelines. Transforms are implemented against the DataFrame trait provided by vegafusion-dataframe.
- Pre-transforming Vega specifications by pre-evaluating their transforms and inlining the resulting transformed data.