From ccf7696fa70c6719c56acdfa5deab74c05e9058c Mon Sep 17 00:00:00 2001
From: Ary Borenszweig <aborenszweig@manas.com.ar>
Date: Sun, 2 Nov 2014 10:05:44 -0300
Subject: [PATCH] Better Array#uniq! implementation
---
src/array.cr | 44 ++++++++++++++++++++++++++++++++------------
1 file changed, 32 insertions(+), 12 deletions(-)
diff --git a/src/array.cr b/src/array.cr
index 88171eb0eb..74eefad3fb 100644
--- a/src/array.cr
+++ b/src/array.cr
@@ -34,7 +34,7 @@ class Array(T)
end
def &(other : Array(U))
- hash = other.each_with_object(Hash(T, Bool).new) { |o, h| h[o] = true }
+ hash = other.to_lookup_hash
ary = Array(T).new(Math.min(length, other.length))
i = 0
each do |obj|
@@ -77,7 +77,7 @@ class Array(T)
def -(other : Array(U))
ary = Array(T).new(length - other.length)
- hash = other.each_with_object(Hash(T, Bool).new) { |o, h| h[o] = true }
+ hash = other.to_lookup_hash
each do |obj|
ary << obj unless hash.has_key?(obj)
end
@@ -264,7 +264,7 @@ class Array(T)
end
true
end
-
+
def fill
each_index { |i| @buffer[i] = yield i }
@@ -628,16 +628,23 @@ class Array(T)
end
def uniq!(&block : T -> U)
- uniq_elements = Set(U).new
- delete_if do |elem|
- key = yield elem
- if uniq_elements.includes? key
- true
- else
- uniq_elements << key
- false
- end
+ if length <= 1
+ return self
+ end
+
+ hash = to_lookup_hash { |elem| yield elem }
+ if length == hash.length
+ return self
+ end
+
+ @length = hash.length
+
+ ptr = @buffer
+ hash.each do |k, v|
+ ptr.value = v
+ ptr += 1
end
+
self
end
@@ -722,4 +729,17 @@ class Array(T)
end
index
end
+
+ protected def to_lookup_hash
+ to_lookup_hash { |elem| elem }
+ end
+
+ protected def to_lookup_hash(&block : T -> U)
+ each_with_object(Hash(U, T).new) do |o, h|
+ key = yield o
+ unless h.has_key?(key)
+ h[key] = o
+ end
+ end
+ end
end
--
GitLab