Metastatic.Analysis.Complexity.Nesting (Metastatic v0.10.4)

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Maximum nesting depth calculation.

Nesting depth measures how many levels deep the code is nested, which affects readability and maintainability. Deeply nested code is harder to understand and reason about.

3-Tuple Format

All MetaAST nodes use the uniform 3-tuple structure: {type_atom, keyword_meta, children_or_value}

What Increases Nesting

  • conditional branches
  • loop bodies
  • lambda bodies
  • exception_handling blocks
  • Nested block structures (when inside above)

Thresholds

  • 0-2: Good, easy to understand
  • 3-4: Moderate, acceptable
  • 5+: High, should be refactored

Examples

# No nesting: depth = 0
iex> ast = {:literal, [subtype: :integer], 42}
iex> Metastatic.Analysis.Complexity.Nesting.calculate(ast)
0

# Single conditional: depth = 1
iex> ast = {:conditional, [], [{:variable, [], "x"}, {:literal, [subtype: :integer], 1}, {:literal, [subtype: :integer], 2}]}
iex> Metastatic.Analysis.Complexity.Nesting.calculate(ast)
1

# Nested conditional: depth = 2
iex> ast = {:conditional, [], [
...>   {:variable, [], "x"},
...>   {:conditional, [], [{:variable, [], "y"}, {:literal, [subtype: :integer], 1}, {:literal, [subtype: :integer], 2}]},
...>   {:literal, [subtype: :integer], 3}]}
iex> Metastatic.Analysis.Complexity.Nesting.calculate(ast)
2

Summary

Functions

calculate(ast)

Calculates maximum nesting depth for a MetaAST node.

Functions

calculate(ast)

@spec calculate(Metastatic.AST.meta_ast()) :: non_neg_integer()

Calculates maximum nesting depth for a MetaAST node.

Returns the depth as a non-negative integer (minimum 0).

Examples

iex> ast = {:binary_op, [category: :arithmetic, operator: :+], [{:variable, [], "x"}, {:literal, [subtype: :integer], 5}]}
iex> Metastatic.Analysis.Complexity.Nesting.calculate(ast)
0

iex> ast = {:loop, [loop_type: :while], [{:variable, [], "condition"}, {:literal, [subtype: :integer], 1}]}
iex> Metastatic.Analysis.Complexity.Nesting.calculate(ast)
1