* Corresponding author: r.pollice@rug.nl requested code from instructions. Until recently, specialized code synthesis models were encoder-decoder architectures 2,3 using abstract syntax trees (AST) . An AST is a hierarchical, tree-like representation of the syntactic structure of code, where each node represents a component of the source code with specific syntactic or semantic meaning. It captures the underlying structure and connections between different elements. Typically, the encoder compresses this hierarchical structure into a fixed representation, and the decoder is trained to generate the target output, a transformed or synthesized code.