Class: Rscons::VarSet

Inherits:
Object
  • Object
show all
Defined in:
lib/rscons/varset.rb

Overview

This class represents a collection of variables which supports efficient deep cloning.

Instance Method Summary collapse

Constructor Details

#initialize(vars = {}) ⇒ VarSet

Create a VarSet.

Parameters:

  • vars (Hash) (defaults to: {}) —

    Optional initial variables.



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# File 'lib/rscons/varset.rb', line 8

def initialize(vars = {})
  @my_vars = {}
  @coa_vars = []
  append(vars)
end

Instance Method Details

#[](key) ⇒ Object

Access the value of variable.

Parameters:

  • key (String, Symbol) —

    The variable name.

Returns:

  • (Object) —

    The variable’s value.



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# File 'lib/rscons/varset.rb', line 19

def [](key)
  if @my_vars.include?(key)
    @my_vars[key]
  else
    @coa_vars.each do |coa_vars|
      if coa_vars.include?(key)
        @my_vars[key] = deep_dup(coa_vars[key])
        return @my_vars[key]
      end
    end
    nil
  end
end

#[]=(key, val) ⇒ Object

Assign a value to a variable.

Parameters:

  • key (String, Symbol) —

    The variable name.

  • val (Object) —

    The value to set.



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# File 'lib/rscons/varset.rb', line 38

def []=(key, val)
  @my_vars[key] = val
end

#append(values) ⇒ VarSet

Add or overwrite a set of variables.

Parameters:

  • values (VarSet, Hash) —

    New set of variables.

Returns:



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# File 'lib/rscons/varset.rb', line 62

def append(values)
  coa!
  if values.is_a?(VarSet)
    values.send(:coa!)
    @coa_vars = values.instance_variable_get(:@coa_vars) + @coa_vars
  else
    @my_vars = deep_dup(values)
  end
  self
end

#expand_varref(varref, lambda_args) ⇒ nil, ...

Replace “${var}” variable references in varref with the expanded variables’ values, recursively.

Parameters:

  • varref (nil, String, Array, Proc, Symbol, TrueClass, FalseClass) —

    Value containing references to variables.

  • lambda_args (Array) —

    Arguments to pass to any lambda variable values to be expanded.

Returns:

  • (nil, String, Array, Symbol, TrueClass, FalseClass) —

    Expanded value with “${var}” variable references replaced.



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# File 'lib/rscons/varset.rb', line 96

def expand_varref(varref, lambda_args)
  if varref.is_a?(String)
    if varref =~ /^(.*)\$\{([^}]+)\}(.*)$/
      prefix, varname, suffix = $1, $2, $3
      varval = expand_varref(self[varname], lambda_args)
      if varval.is_a?(String) or varval.nil?
        expand_varref("#{prefix}#{varval}#{suffix}", lambda_args)
      elsif varval.is_a?(Array)
        varval.map {|vv| expand_varref("#{prefix}#{vv}#{suffix}", lambda_args)}.flatten
      else
        raise "I do not know how to expand a variable reference to a #{varval.class.name} (from #{varname.inspect} => #{self[varname].inspect})"
      end
    else
      varref
    end
  elsif varref.is_a?(Array)
    varref.map do |ent|
      expand_varref(ent, lambda_args)
    end.flatten
  elsif varref.is_a?(Proc)
    expand_varref(varref[*lambda_args], lambda_args)
  elsif varref.nil?
    nil
  elsif varref.is_a?(Symbol)
    varref
  elsif varref.is_a?(TrueClass)
    varref
  elsif varref.is_a?(FalseClass)
    varref
  else
    raise "Unknown varref type: #{varref.class} (#{varref.inspect})"
  end
end

#include?(key) ⇒ Boolean

Check if the VarSet contains a variable.

Parameters:

  • key (String, Symbol) —

    The variable name.

Returns:

  • (Boolean) —

    Whether the VarSet contains the variable.



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# File 'lib/rscons/varset.rb', line 47

def include?(key)
  if @my_vars.include?(key)
    true
  else
    @coa_vars.find do |coa_vars|
      coa_vars.include?(key)
    end
  end
end

#inspect ⇒ String

Return a String representing the VarSet.

Returns:

  • (String) —

    Representation of the VarSet.



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# File 'lib/rscons/varset.rb', line 153

def inspect
  to_h.inspect
end

#merge(other = {}) ⇒ VarSet Also known as: clone

Create a new VarSet object based on the first merged with other.

Parameters:

  • other (VarSet, Hash) (defaults to: {}) —

    Other variables to add or overwrite.

Returns:

  • (VarSet) —

    The newly created VarSet.



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# File 'lib/rscons/varset.rb', line 78

def merge(other = {})
  coa!
  varset = self.class.new
  varset.instance_variable_set(:@coa_vars, @coa_vars.dup)
  varset.append(other)
end

#to_h ⇒ Hash

Return a Hash containing all variables in the VarSet.

This method is not terribly efficient. It is intended to be used only by debugging code to dump out a VarSet’s variables.

Returns:

  • (Hash) —

    All variables in the VarSet.

Since:

  • 1.8.0



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# File 'lib/rscons/varset.rb', line 138

def to_h
  result = deep_dup(@my_vars)
  @coa_vars.reduce(result) do |result, coa_vars|
    coa_vars.each_pair do |key, value|
      unless result.include?(key)
        result[key] = deep_dup(value)
      end
    end
    result
  end
end

#values_at(*keys) ⇒ Array

Return an array containing the values associated with the given keys.

Parameters:

  • keys (Array<String, Symbol>) —

    Keys to look up in the VarSet.

Returns:

  • (Array) —

    An array containing the values associated with the given keys.



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# File 'lib/rscons/varset.rb', line 164

def values_at(*keys)
  keys.map do |key|
    self[key]
  end
end