Class: Semdiff::AliasingCompiler

Inherits:
Prism::MutationCompiler
  • Object
show all
Includes:
Prism::DSL, CompilerUtils
Defined in:
lib/semdiff/aliasing_compiler.rb

Overview

AliasingCompiler is a compiler that unifies method aliases according to the Ruby style guide (https://rubystyle.guide/) based on type information.

Examples:

```ruby
# Original        Canonical Form
[].collect        [].map
{}.detect         {}.find
(1..5).find_all   (1..5).select
[1, 2].inject(:+) [1, 2].reduce(:+)
[1].member?(1)    [1].include?(1)
"abc".length      "abc".size
[1,2,3].length    [1,2,3].size
```

Constant Summary collapse

UNTYPED_ALIASES =

NOTE: Enumerables (and others for length/size) typically respond to both the key and value method names in this map. We therefore assume that any Ruby object does (and should) have both methods for every pair, if they have at least one. This greatly simplifies the process of accounting for every (standard library) object and also allows us to map custom subclass (e.g., Foo < Array) methods automatically.

{
  collect: :map,
  detect: :find,
  find_all: :select,
  inject: :reduce,
  member?: :include?,
  length: :size
}.freeze

Instance Method Summary collapse

Methods included from CompilerUtils

inherit_newline

Instance Method Details

#visit_call_node(node) ⇒ Object 



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# File 'lib/semdiff/aliasing_compiler.rb', line 39

def visit_call_node(node)
  receiver  = visit(node.receiver)
  arguments = visit(node.arguments)
  block     = visit(node.block)
  result    = nil

  if UNTYPED_ALIASES.key?(node.name)
    canonical_name = UNTYPED_ALIASES[node.name]
    # It might be worth updating the message_loc to reflect
    # the new size. However, the underlying message buffer
    # would still point to the original name.
    result = node.copy(
      name: canonical_name,
      receiver: receiver,
      arguments: arguments,
      block: block
    )
  end

  if result
    CompilerUtils.inherit_newline(node, result)
  else
    node.copy(receiver: receiver, arguments: arguments, block: block)
  end
end