summaryrefslogtreecommitdiff
path: root/lib/rake/invocation_chain.rb
diff options
context:
space:
mode:
Diffstat (limited to 'lib/rake/invocation_chain.rb')
-rw-r--r--lib/rake/invocation_chain.rb42
1 files changed, 24 insertions, 18 deletions
diff --git a/lib/rake/invocation_chain.rb b/lib/rake/invocation_chain.rb
index 8a01ab4..dae9a35 100644
--- a/lib/rake/invocation_chain.rb
+++ b/lib/rake/invocation_chain.rb
@@ -3,44 +3,50 @@ module Rake
####################################################################
# InvocationChain tracks the chain of task invocations to detect
# circular dependencies.
- class InvocationChain
- def initialize(value, tail)
- @value = value
- @tail = tail
- end
+ class InvocationChain < LinkedList
- def member?(obj)
- @value == obj || @tail.member?(obj)
+ # Is the invocation already in the chain?
+ def member?(invocation)
+ head == invocation || tail.member?(invocation)
end
- def append(value)
- if member?(value)
- fail RuntimeError, "Circular dependency detected: #{to_s} => #{value}"
+ # Append an invocation to the chain of invocations. It is an error
+ # if the invocation already listed.
+ def append(invocation)
+ if member?(invocation)
+ fail RuntimeError, "Circular dependency detected: #{to_s} => #{invocation}"
end
- self.class.new(value, self)
+ conj(invocation)
end
+ # Convert to string, ie: TOP => invocation => invocation
def to_s
- "#{prefix}#{@value}"
+ "#{prefix}#{head}"
end
- def self.append(value, chain)
- chain.append(value)
+ # Class level append.
+ def self.append(invocation, chain)
+ chain.append(invocation)
end
private
def prefix
- "#{@tail.to_s} => "
+ "#{tail.to_s} => "
end
- class EmptyInvocationChain
+ # Null object for an empty chain.
+ class EmptyInvocationChain < LinkedList::EmptyLinkedList
+ @parent = InvocationChain
+
def member?(obj)
false
end
- def append(value)
- InvocationChain.new(value, self)
+
+ def append(invocation)
+ conj(invocation)
end
+
def to_s
"TOP"
end