{
  "task": {
    "id": "case_111",
    "name": "last_element_with_zero_padding",
    "summary": "Returns the last element of the sequence and pads the rest with zeros.",
    "examples": [
      {
        "input": [
          "BOS",
          2,
          4,
          2,
          6,
          4,
          8,
          6,
          1,
          3
        ],
        "output": [
          "BOS",
          3.0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0
        ]
      },
      {
        "input": [
          "BOS",
          4,
          1,
          7,
          5,
          1,
          4,
          0,
          9,
          5
        ],
        "output": [
          "BOS",
          5.0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0
        ]
      },
      {
        "input": [
          "BOS",
          10,
          10,
          7,
          4,
          3,
          7,
          7,
          2,
          5
        ],
        "output": [
          "BOS",
          5.0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0
        ]
      },
      {
        "input": [
          "BOS",
          8,
          0,
          10,
          10,
          9,
          2,
          6,
          3,
          8
        ],
        "output": [
          "BOS",
          8.0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0
        ]
      },
      {
        "input": [
          "BOS",
          6,
          3,
          10,
          7,
          4,
          6,
          9,
          2,
          6
        ],
        "output": [
          "BOS",
          6.0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0
        ]
      }
    ],
    "is_categorical": true
  },
  "program": "length = rasp.SelectorWidth(rasp.Select(rasp.tokens, rasp.tokens, rasp.Comparison.TRUE)).named(\"length\")\nlast_element_selector = rasp.Select(rasp.indices, rasp.Map(lambda x: x - 1, length), rasp.Comparison.EQ).named(\"last_element_selector\")\nlast_element_sequence = rasp.Aggregate(last_element_selector, rasp.tokens).named(\"last_element_sequence\")\nreturn rasp.SequenceMap(lambda x, y: x if y == 0 else 0, last_element_sequence, rasp.indices)",
  "components": [
    {
      "id": "L0H0_ATTN",
      "hook": "blocks.0.attn.hook_result[0]",
      "role": {
        "tag": "AGGREGATOR",
        "note": "Produces a shared sequence length signal used to identify the last position."
      },
      "rasp_vars": [
        "length"
      ],
      "labels": [
        "length_5_selector_width_attn_output"
      ]
    },
    {
      "id": "L0_MLP",
      "hook": "blocks.0.mlp.hook_post",
      "role": {
        "tag": "MAPPER",
        "note": "Turns the length-related signal into a sequence-length feature."
      },
      "rasp_vars": [
        "length"
      ],
      "labels": [
        "length_5",
        "length_5_selector_width_attn_output"
      ]
    },
    {
      "id": "L1_MLP",
      "hook": "blocks.1.mlp.hook_post",
      "role": {
        "tag": "MAPPER",
        "note": "Computes the last element's index by applying element-wise subtraction to the sequence-length feature."
      },
      "rasp_vars": [
        "last_index"
      ],
      "labels": [
        "map_4"
      ]
    },
    {
      "id": "L2H0_ATTN",
      "hook": "blocks.2.attn.hook_result[0]",
      "role": {
        "tag": "ROUTER",
        "note": "Retrieves the last token and makes it available for placement into the output sequence."
      },
      "rasp_vars": [
        "last_element_sequence"
      ],
      "labels": [
        "last_element_sequence_2"
      ]
    },
    {
      "id": "L2_MLP",
      "hook": "blocks.2.mlp.hook_post",
      "role": {
        "tag": "COMBINER",
        "note": "Outputs the last token in the first slot and writes zeros in every other slot."
      },
      "rasp_vars": [
        "output_sequence"
      ],
      "labels": [
        "sequence_map_1"
      ]
    }
  ]
}