---
# System prepended metadata

title: '`doDot` specs'

---


### `toDot` Method Specification for `VerkleTrie`

#### Description

The enhancement of `VerkleTrie` includes two key features:

1. **Implementation of `toDot` Method for String Representation:**
   - The `toDot` method is designed to provide a human-readable string representation of `VerkleTrie` in Dot format, aiding in debugging and visualizing the trie structure. The method will include:
     - `BranchNodes` featuring a `commitment` attribute.
     - `StemNodes` with attributes such as `stem`, `leftCommitment`, and `rightCommitment`.
     - `LeafNodes` that include `suffix` and `value` attributes.
     - A unique `location` attribute for each node for identification purposes.

2. **File Storing Mechanism for `toDot` Output:**
   - The method will have the capability to save its output in a file, enhancing usability for further analysis or sharing. Key features include:
     - User-friendly saving of the Dot format output.
     - Error handling for write permissions or file system issues.
     - Optional specification of file path and name for output storage.

#### Expected Behavior

- The `toDot` method returns the `VerkleTrie` representation in Dot format, detailing different node types with their specific attributes.
- It allows users to save this output into a file, providing a practical tool for debugging and analysis.

#### Example

Running the test function available at [GitHub - go-verkle](https://github.com/ethereum/go-verkle/blob/76183efeacf48494e9ff1849851fbb83d6405eee/tree_test.go#L931) using the command `go test . -run TestToDot -v` generates a Dot file representation of the `VerkleTrie`. Here's an example of the tree generated from the test:

\```dot
digraph D {
    internal [label="I: b8f1..."]
    leaf00 [label="L: 080d...
    C: 5677...
    C₁: 38f3...
    C₂:0000..."]
    internal -> leaf00
    val0000 [label="0000..."]
    leaf00 -> val0000
    ...
    internal40 -> leaf4020
    val402000 [label="0000..."]
    leaf4020 -> val402000
}
\```

This output results from inserting a value at specific keys. The leaves and stems in the `VerkleTrie` are represented accordingly, with leaves on the Geth side being either Leaf or Stem Nodes in the codebase.

#### Identifiers in the Dot File

Regarding identifiers such as `leaf00c7 -> val00c700`, they are derived from the traversal path within the `VerkleTrie`. For instance, `leaf00c7` indicates a key that passes through child `00` in the first branch node and child `c7` in the second one. These identifiers help in understanding the structure and relationships within the trie.

# Verkle Trie Representation in Dot Format

## Overview
This document describes the representation of a `VerkleTrie` in Dot format, based on the test output from the Ethereum `go-verkle` implementation.

## Internal Nodes
- **Description**: Internal nodes represent branches in the trie.
- **Examples**:
  - `internal [label="I: b8f166af..."]`: Root node of the trie.
  - `internal40 [label="I: f8772f82..."]`: Another internal node.

## Leaf Nodes
- **Description**: Leaf nodes are the endpoints of the trie where values are stored.
- **Unique Identifier**: Each leaf node is indicated by `L: [hexadecimal value]`.
- **Commitment Attributes**: Represented by `C`, `C₁`, `C₂`, etc.
- **Examples**:
  - `leaf00 [label="L: 080d832a..."]`: A leaf node connected to the root internal node.
  - `leaf4000 [label="L: 0882d10c..."]` and `leaf4020 [label="L: 140dcec1..."]`: Leaf nodes connected to the `internal40` node.

## Values
- **Description**: Represents the data stored in the leaf nodes.
- **Examples**:
  - `val0000 [label="00000000..."]`: Value stored in `leaf00`.
  - `val400000 [label="00000000..."]` and `val402000 [label="00000000..."]`: Values stored in `leaf4000` and `leaf4020`, respectively.

## Edges
- **Description**: Show the connections between nodes.
- **Examples**:
  - `internal -> leaf00` and `internal40 -> leaf4000`: Connections from internal nodes to their respective leaf nodes.
  - `leaf00 -> val0000`, `leaf4000 -> val400000`, and `leaf4020 -> val402000`: Connections from leaf nodes to their respective value nodes.

## Insertion Context
- The tree is the result of inserting the value `0000000000000000000000000000000000000000000000000000000000000000` at keys:
  - `4020000000000000000000000000000000000000000000000000000000000000`
  - `4000000000000000000000000000000000000000000000000000000000000000`
  - `0000000000000000000000000000000000000000000000000000000000000000`
- This results in the creation of internal nodes (`internal`, `internal40`) and leaf nodes (`leaf00`, `leaf4000`, `leaf4020`), each storing the same value (`val0000`, `val400000`, `val402000`).

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*Generated from the `VerkleTrie` Dot format output in Ethereum's `go-verkle` implementation.*
