Class: Ryac::GvarRenameMapping

Inherits:
Object
  • Object
show all
Defined in:
lib/ryac/analysis/gvar/rename_mapping.rb,
sig/ryac/analysis/gvar/rename_mapping.rbs

Constant Summary collapse

PERL_SPELLINGS =

One pairing of English name to punctuation spelling. SpellingShorten rewrites reads and plain writes to the short form; both spellings also join BUILT_IN_GLOBALS below, so the node kinds it does not rewrite (targets, operator/or/and writes) can never be renamed either.

Returns:

  • (Hash[Symbol, String]) 
{
  '$PROGRAM_NAME': '$0',
  '$LOAD_PATH': '$:',
  '$LOADED_FEATURES': '$"',
}.freeze
BUILT_IN_GLOBALS =

Built-in globals that must never be renamed: Ruby defines their storage, so a renamed spelling reads nil and writes into a dead cell.

Returns:

  • (Set[Symbol]) 
(Set.new(%i[
  $stdout $stderr $stdin $DEBUG $VERBOSE $FILENAME
  $ERROR_INFO $ERROR_POSITION $FIELD_SEPARATOR $OFS $OUTPUT_FIELD_SEPARATOR
  $RS $INPUT_RECORD_SEPARATOR $ORS $OUTPUT_RECORD_SEPARATOR
  $INPUT_LINE_NUMBER $NR $LAST_READ_LINE $DEFAULT_OUTPUT $DEFAULT_INPUT
  $PID $PROCESS_ID $CHILD_STATUS $LAST_MATCH_INFO $IGNORECASE
  $ARGV $MATCH $PREMATCH $POSTMATCH $LAST_PAREN_MATCH $FS
  $0 $: $; $, $. $/ $\\ $_ $< $> $! $@ $~ $& $` $' $+ $*
  $" $? $$ $-0 $-F $-I $-K $-W $-a $-d $-i $-l $-p $-v $-w
  $1 $2 $3 $4 $5 $6 $7 $8 $9
]) + PERL_SPELLINGS.keys + PERL_SPELLINGS.values.map(&:to_sym)).freeze
PREFIX =

Returns:

  • (String) 
'$'
KEPT_NAME_MAX =

Sigil + one character is already minimal — the same rule the SiteBucketMapping families derive from their prefix.

Returns:

  • (Integer) 
PREFIX.size + 1

Instance Method Summary collapse

Constructor Details

#initialize ⇒ GvarRenameMapping

Returns a new instance of GvarRenameMapping.



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# File 'lib/ryac/analysis/gvar/rename_mapping.rb', line 29

def initialize
  @gvars = {}
  @excluded_names = Set.new
  @written_names = Set.new
  @node_short_names = {}
end

Instance Method Details

#add_site(name, node, write: false) ⇒ void

This method returns an undefined value.

Parameters:

  • name (Symbol)
  • node (Prism::Node)
  • write: (Boolean) (defaults to: false) 


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# File 'lib/ryac/analysis/gvar/rename_mapping.rb', line 36

def add_site(name, node, write: false)
  return if BUILT_IN_GLOBALS.include?(name)
  @written_names << name if write
  @gvars[name] ||= []
  @gvars[name] << node
end

#assign_short_names ⇒ void

This method returns an undefined value.



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# File 'lib/ryac/analysis/gvar/rename_mapping.rb', line 52

def assign_short_names
  existing_names = Set.new
  @gvars.each_key do |name|
    existing_names << name.to_s if name.to_s.size <= KEPT_NAME_MAX
  end

  generator = NameGenerator.new(existing_names, prefix: PREFIX)
  sorted_gvars = @gvars.sort_by do |name, nodes|
    -(name.to_s.size * nodes.size)
  end

  sorted_gvars.each do |name, nodes|
    next if @excluded_names.include?(name)
    next if name.to_s.size <= KEPT_NAME_MAX
    # A global the program only reads is either a built-in this list
    # does not know or nil everywhere — renaming it can only break.
    next unless @written_names.include?(name)

    short_name = generator.next_name
    savings = (name.to_s.size - short_name.size) * nodes.size
    next unless savings > 0

    nodes.each { |n| @node_short_names[AstUtils.location_key(n)] = short_name }
  end
end

#exclude_name(name) ⇒ void

This method returns an undefined value.

Parameters:

  • name (Symbol) 


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# File 'lib/ryac/analysis/gvar/rename_mapping.rb', line 43

def exclude_name(name)
  @excluded_names << name
end

#node_mapping ⇒ Hash[[Integer, Integer], String]

Returns:

  • (Hash[[Integer, Integer], String]) 


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# File 'lib/ryac/analysis/gvar/rename_mapping.rb', line 78

def node_mapping
  @node_short_names.dup
end