{
  "task": {
    "id": "case_21",
    "name": "unique_token_extractor",
    "summary": "Extract unique tokens from a string",
    "examples": [
      {
        "input": [
          "BOS",
          "b",
          "b",
          "a",
          "a",
          "b",
          "b",
          "a",
          "a",
          "a"
        ],
        "output": [
          "BOS",
          "b",
          null,
          "a",
          null,
          null,
          null,
          null,
          null,
          null
        ]
      },
      {
        "input": [
          "BOS",
          "c",
          "c",
          "a",
          "c",
          "a",
          "c",
          "c",
          "a",
          "a"
        ],
        "output": [
          "BOS",
          "c",
          null,
          "a",
          null,
          null,
          null,
          null,
          null,
          null
        ]
      },
      {
        "input": [
          "BOS",
          "c",
          "a",
          "c",
          "c",
          "a",
          "a",
          "c",
          "b",
          "c"
        ],
        "output": [
          "BOS",
          "c",
          "a",
          null,
          null,
          null,
          null,
          null,
          "b",
          null
        ]
      },
      {
        "input": [
          "BOS",
          "c",
          "c",
          "c",
          "b",
          "c",
          "b",
          "b",
          "c",
          "b"
        ],
        "output": [
          "BOS",
          "c",
          null,
          null,
          "b",
          null,
          null,
          null,
          null,
          null
        ]
      },
      {
        "input": [
          "BOS",
          "c",
          "c",
          "c",
          "a",
          "c",
          "b",
          "a",
          "b",
          "b"
        ],
        "output": [
          "BOS",
          "c",
          null,
          null,
          "a",
          null,
          "b",
          null,
          null,
          null
        ]
      }
    ],
    "is_categorical": true
  },
  "program": "tokens_with_indices = rasp.SequenceMap(lambda x, i: (x, i), sop, rasp.indices)\noccurrences_selector = rasp.Select(tokens_with_indices, tokens_with_indices, lambda k, q: k[0] == q[0] and k[1] <= q[1])\noccurrences_per_row = rasp.SelectorWidth(occurrences_selector)\nfirst_occurrences_indices = rasp.SequenceMap(lambda count, i: i if count == 1 else -1, occurrences_per_row, rasp.indices)\ntokens_selector = rasp.Select(first_occurrences_indices, rasp.indices, rasp.Comparison.EQ).named(\"unique_tokens_selector\")\nreturn rasp.Aggregate(tokens_selector, sop, default=None).named(\"unique_tokens\")",
  "components": [
    {
      "id": "L0_MLP",
      "hook": "blocks.0.mlp.hook_post",
      "role": {
        "tag": "COMBINER",
        "note": "Creates a combined 'token + position' representation so later steps can tell which token occurred where."
      },
      "rasp_vars": [
        "tokens_with_indices"
      ],
      "labels": [
        "sequence_map_6"
      ]
    },
    {
      "id": "L1H0_ATTN",
      "hook": "blocks.1.attn.hook_result[0]",
      "role": {
        "tag": "AGGREGATOR",
        "note": "Aggregates matching positions (same token, earlier-or-equal index) into a per-position count of how many times each token has appeared up to and including the current position."
      },
      "rasp_vars": [
        "occurrences_selector"
      ],
      "labels": [
        "selector_width_4_selector_width_attn_output"
      ]
    },
    {
      "id": "L1_MLP",
      "hook": "blocks.1.mlp.hook_post",
      "role": {
        "tag": "MAPPER",
        "note": "Converts the per-position summary into the explicit running count of that token's occurrences so far. (how many times this token has appeared up to here)."
      },
      "rasp_vars": [
        "occurrences_per_row"
      ],
      "labels": [
        "selector_width_4",
        "selector_width_4_selector_width_attn_output"
      ]
    },
    {
      "id": "L2_MLP",
      "hook": "blocks.2.mlp.hook_post",
      "role": {
        "tag": "COMBINER",
        "note": "Computes a per-position routing key that marks the first occurrence positions and marks all others as an invalid index."
      },
      "rasp_vars": [
        "first_occurrences_indices"
      ],
      "labels": [
        "sequence_map_3"
      ]
    },
    {
      "id": "L3H0_ATTN",
      "hook": "blocks.3.attn.hook_result[0]",
      "role": {
        "tag": "AGGREGATOR",
        "note": "Attends to the position (if any) whose 'first occurrences indices' equals the current index, and aggregates the token value from there, or None if no such position exists."
      },
      "rasp_vars": [
        "unique_tokens"
      ],
      "labels": [
        "unique_tokens_1"
      ]
    }
  ]
}