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Prefix Trie Path Compressed Edge Table

Bounded explicit prefix trie with root ID 0, unique sibling UTF-16 code-unit edges and terminal flags; compress unary nonterminal chains to multi-code-unit edge labels while retaining source endpoint IDs and all terminal boundaries.

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Description

Compress unary nonterminal chains to multi-code-unit edge labels while retaining source endpoint IDs and all terminal boundaries.

A trie stores literal words as root-to-node character paths, with terminal flags marking complete words. A terminal can also have children, and an existing prefix path need not be a stored word. This family uses one UTF-16 code unit per ordinary edge, so code-unit length differs from a displayed character or Unicode code-point count.

Compress unary nonterminal chains to multi-code-unit edge labels while retaining source endpoint IDs and all terminal boundaries.

When to use this tool

Use this tool to compress unary nonterminal chains to multi-code-unit edge labels while retaining source endpoint IDs and all terminal boundaries.

How to use the tool and how it works

  1. Enter nodesJson using the definitions below. Serialize JSON text fields in the decoded shape shown below.
  2. Run the operation. Resolve input-format errors before interpreting an output.
  3. Read result.rootTerminal, result.edges, using the stated boundary, ordering, sign and absence conventions.

Walk from the root in supplied child order, combining consecutive edges through nonterminal unary nodes. Return {from,to,label,terminal} edges and preserve the root terminal flag separately.1

Input fieldMeaning and unitsAccepted input
nodesJsonJSON array of {id,parent,character,terminal} nodes under the complete root-zero trie rules below.Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply.

These decoded structures show the examples inside JSON text fields. Supply their serialized JSON strings as input.

json
{
  "nodesJson": [
    {
      "id": 0,
      "parent": null,
      "character": "",
      "terminal": false
    },
    {
      "id": 1,
      "parent": 0,
      "character": "a",
      "terminal": true
    },
    {
      "id": 2,
      "parent": 1,
      "character": "b",
      "terminal": true
    },
    {
      "id": 3,
      "parent": 0,
      "character": "b",
      "terminal": true
    }
  ]
}
Output fieldInterpretation
resultObject containing the fields below.
result.rootTerminalWhether the original root stores the empty word.
result.edgesCompressed edge records {from,to,label,terminal}, retaining original endpoint IDs.
json
{
  "input": {
    "nodesJson": "[{\"id\": 0, \"parent\": null, \"character\": \"\", \"terminal\": false}, {\"id\": 1, \"parent\": 0, \"character\": \"a\", \"terminal\": true}, {\"id\": 2, \"parent\": 1, \"character\": \"b\", \"terminal\": true}, {\"id\": 3, \"parent\": 0, \"character\": \"b\", \"terminal\": true}]"
  },
  "output": {
    "result": {
      "rootTerminal": false,
      "edges": [
        {
          "from": 0,
          "to": 1,
          "label": "a",
          "terminal": true
        },
        {
          "from": 1,
          "to": 2,
          "label": "b",
          "terminal": true
        },
        {
          "from": 0,
          "to": 3,
          "label": "b",
          "terminal": true
        }
      ]
    }
  }
}

Limitations and assumptions

  • Compressed endpoint IDs are original IDs; terminal boundaries are retained and labels concatenate UTF-16 code units.
  • Ordinary node tables have at most 128 nodes with distinct IDs 0–127, one root ID 0 with empty character and null parent, unique parent/character edges, complete acyclic parent links and a boolean terminal flag. Every nonroot character is exactly one UTF-16 code unit.
  • Every declared outer field is required and unknown outer fields are rejected. Strings and JSON text have size limits, lists are bounded to 128 entries, and JSON nesting/node counts are bounded. Tighter operation-specific bounds stated above take precedence.
  • Ordinary numeric outputs must be finite and within safe-integer magnitude. Exact large lengths/counts use decimal strings. Original record indexes and code-unit positions are zero-based; span ends are exclusive unless stated otherwise.

Alternative or Complementary methods

Choose word membership, prefix existence, completion or ranking according to the question. Normalize text separately if needed; these operations preserve exact code units and caller order.

References

  1. Tool behavior and example: Prefix Trie Path Compressed Edge Table — tool.io

Similar or alternative tools

  • Prefix Trie Compressed Edge Node Expander

    Expand an explicit compressed rooted trie edge table into stable insertion-code-unit nodes, validating complete unique-parent acyclic structure and unambiguous outgoing first characters; IDs are reallocated, not preserved.

  • Prefix Trie Query Missing Edge Witness

    Bounded explicit prefix trie with root ID 0, unique sibling UTF-16 code-unit edges and terminal flags; report the first missing literal edge with matched prefix; a fully matched nonterminal path is structurally present, not a missing edge.