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Merlin Language Reference

Merlin is a domain-specific language for visualizing data structures and algorithms interactively. It is designed to be simple, readable, and powerful for both teaching and learning.

Core Concepts​

  • Data Structures: Define arrays, matrices, graphs, stacks, trees, and text blocks with rich attributes.
  • Pages: Use page to create steps or slides in your visualization.
  • Show: Use show to display a data structure on a page.
  • Methods: Manipulate data structures with intuitive methods (e.g., setColor, addNode).

Basic Syntax​

array numbers = {
    value: [1, 2, 3]
    color: ["blue", "green", "red"]
}

page
show numbers

Data Structure Types​

Merlin provides several built-in data structure types. For detailed documentation, examples, and methods for each type, see the Data Structures section.

Array​

array arr = {
    value: [1,2,3]
    color: ["red", null, "blue"]
    arrow: [null, "i", null]
}

→ Array Documentation

Matrix​

matrix grid = {
    value: [[1,2],[3,4]]
    color: [[null, "red"], [null, null]]
}

→ Matrix Documentation

Graph​

graph g = {
    nodes: [A,B,C]
    edges: [A-B, B-C]
    value: [1,2,3]
    color: ["red", null, "blue"]
}

→ Graph Documentation

Stack​

stack s = {
    value: ["main", "func"]
    color: [null, "blue"]
}

→ Stack Documentation

Tree​

tree t = {
    nodes: [root, left, right]
    children: [root-left, root-right]
    value: [1,2,3]
}

→ Tree Documentation

LinkedList​

linkedlist ll = {
    nodes: [head, node1, tail]
    value: [1, 2, 3]
}

→ LinkedList Documentation

Text​

text label = {
    value: "Hello, world!"
    fontSize: 16
    color: "gray"
}

→ Text Documentation

Pages and Visualization​

  • page creates a new visualization step. You can add a layout (e.g., page 2x2).
  • show displays a structure, optionally at a grid position: show arr (0, 1).

Methods and Operations​

Merlin provides a rich set of methods for manipulating data structures. For a complete reference of all available methods, see the Methods Reference.

Common Method Categories​

  • Setters: setColor, setValue, setArrow, setHidden, etc.
  • Insert/Remove: insertValue, removeValue, addNode, removeNode, addEdge, removeEdge, etc.
  • Matrix/Array: addRow, addColumn, removeRow, removeColumn, addBorder.
  • Tree: addChild, setChild, removeSubtree.
  • Text: setFontSize, setColor, setAlign, etc.

For detailed examples and comprehensive documentation of each data structure, visit the Data Structures section. For more, see the Getting Started guide and the example gallery!