[06-assemble-full-block] built ONE complete Transformer block: a self-attention sublayer and a feed-forward sublayer, each wrapped in [01-layer-normalization-forward]'s normalization and [03-residual-connection]'s residual connection. A real Transformer, and every modern LLM, is overwhelmingly just MANY of these identical-in-STRUCTURE (but independently-PARAMETERIZED) blocks, stacked one after another, each block's output feeding directly into the next block's input. This is genuinely most of what "scaling up a model" means in practice: GPT-2 small has 12 blocks, GPT-3 has 96, and the largest modern LLMs stack well over a hundred, each one adding another opportunity for the representation at every position to be further refined against the rest of the sequence.
Each block in the stack has its OWN independently-learned parameters (its own attention weights, its own FFN weights, its own LayerNorm gamma/beta), never shared across blocks, so a 12-block model has 12x as many block-level parameters as a single block, even though every block runs the identical FORWARD computation [06-assemble-full-block] already implements.
Implement stack_transformer_blocks(x, num_heads, blocks_params, mask, eps). blocks_params is a list of dicts, one per block, each containing that block's own set of weights (weight_o, bias_o, ffn_weight1, ffn_bias1, ffn_weight2, ffn_bias2, gamma1, beta1, gamma2, beta2, the exact keyword arguments [06-assemble-full-block]'s transformer_block_forward expects). Run x through each block IN ORDER, each block's output becoming the NEXT block's input.
i's output is block i+1's input, never the other way around, and never independently against the original x.num_heads, mask, and eps are shared across every block in the stack (a real Transformer typically uses the same head count and mask at every layer); only the WEIGHTS differ per block.blocks_params list returns x completely unchanged (zero blocks means zero transformation).for params in blocks_params:
x = transformer_block_forward(x, num_heads, mask=mask, eps=eps, **params)
return x
Each iteration REASSIGNS x to that block's output, so the next iteration's transformer_block_forward call automatically receives the previous block's output as its input.
**params unpacks a block's dict directly into transformer_block_forward's keyword arguments (weight_o=params["weight_o"], ffn_weight1=params["ffn_weight1"], and so on), so each dict in blocks_params needs exactly the keys [06-assemble-full-block]'s transformer_block_forward expects beyond x, num_heads, mask, and eps.
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