Class: Ast::Merge::NodeTyping::FrozenWrapper

Inherits:
Wrapper
  • Object
show all
Includes:
Freezable
Defined in:
lib/ast/merge/node_typing.rb

Overview

Wrapper for frozen AST nodes that includes Freezable behavior.

FrozenWrapper extends Wrapper to add freeze node semantics, making the wrapped node satisfy both the NodeTyping API and the Freezable API. This enables composition where frozen nodes are:

  • Wrapped AST nodes (can unwrap to get original)

  • Typed nodes (have merge_type)

  • Freeze nodes (satisfy is_a?(Freezable) and freeze_node?)

## Key Distinction from FreezeNodeBase

FrozenWrapper and FreezeNodeBase both include Freezable, but they represent fundamentally different concepts:

### FrozenWrapper (this class)

  • Wraps an AST node that has a freeze marker in its leading comments

  • The node is still a structural AST node (e.g., a ‘gem` call in a gemspec)

  • During matching, we want to match by the underlying node’s IDENTITY (e.g., the gem name), NOT by the full content

  • Signature generation should unwrap and use the underlying node’s structure

  • Example: ‘# token:freezengem “example_gem”, “~> 1.0”` wraps a CallNode

### FreezeNodeBase

  • Represents an explicit freeze block with ‘# token:freeze … # token:unfreeze`

  • The entire block is opaque content that should be preserved verbatim

  • During matching, we match by the full CONTENT of the block

  • Signature generation uses freeze_signature (content-based)

  • Example: A multi-line comment block with custom formatting

## Signature Generation Behavior

When FileAnalyzable#generate_signature encounters a FrozenWrapper:

  1. It unwraps to get the underlying AST node

  2. Passes the unwrapped node to the signature_generator

  3. This allows the signature generator to recognize the node type (e.g., Prism::CallNode) and generate appropriate signatures

This is critical because signature generators check for specific AST types. If we passed the wrapper, the generator wouldn’t recognize it as a CallNode and would fall back to a generic signature, breaking matching.

Examples:

Creating a frozen wrapper

frozen = NodeTyping::FrozenWrapper.new(prism_node, :frozen)
frozen.freeze_node?  # => true
frozen.is_a?(Ast::Merge::Freezable)  # => true
frozen.unwrap  # => prism_node

See Also:

Instance Attribute Summary

Attributes inherited from Wrapper

#merge_type, #node

Instance Method Summary collapse

Methods included from Freezable

#freeze_node?, #freeze_signature

Methods inherited from Wrapper

#==, #eql?, #hash, #method_missing, #respond_to_missing?, #typed_node?, #unwrap

Constructor Details

#initialize(node, merge_type = :frozen) ⇒ FrozenWrapper

Create a frozen wrapper for an AST node.

Parameters:

  • node (Object) —

    The AST node to wrap

  • merge_type (Symbol) (defaults to: :frozen) —

    The merge type (defaults to :frozen)



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# File 'lib/ast/merge/node_typing.rb', line 179

def initialize(node, merge_type = :frozen)
  super(node, merge_type)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Ast::Merge::NodeTyping::Wrapper

Instance Method Details

#frozen_node? ⇒ Boolean

Returns true to indicate this is a frozen node. Overrides both Wrapper#typed_node? context and provides freeze_node? from Freezable.

Returns:

  • (Boolean) —

    true



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# File 'lib/ast/merge/node_typing.rb', line 187

def frozen_node?
  true
end

#inspect ⇒ Object

Forward inspect to show frozen status.



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# File 'lib/ast/merge/node_typing.rb', line 208

def inspect
  "#<NodeTyping::FrozenWrapper merge_type=#{@merge_type.inspect} node=#{@node.inspect}>"
end

#signature ⇒ Array

Returns the signature for this frozen node. Uses the freeze_signature from Freezable module.

Returns:

  • (Array) —

    Signature in the form [:FreezeNode, content]



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# File 'lib/ast/merge/node_typing.rb', line 203

def signature
  freeze_signature
end

#slice ⇒ String

Returns the content of this frozen node. Delegates to the wrapped node’s slice method.

Returns:

  • (String) —

    The node content



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# File 'lib/ast/merge/node_typing.rb', line 195

def slice
  @node.slice
end