v2.0

.gitignore

@@ -2,7 +2,6 @@
 *.o
 *.a
 *.so
-*.out
 
 # Folders
 _obj
@@ -22,3 +21,9 @@ _testmain.go
 
 *.exe
 *.test
+*.prof
+
+### Code ###
+# Visual Studio Code - https://code.visualstudio.com/
+.settings/
+.vscode/

.travis.yml

@@ -1,13 +1,20 @@
 sudo: false
+
 language: go
-go: go1.6
-install:
-  - go get -v golang.org/x/tools/cmd/cover
-  - go get -t github.com/smartystreets/goconvey
-  - go get github.com/jacobsa/oglematchers
+go:
+  - 1.6.2
+  - tip
+
+before_install:
+  - go get github.com/mattn/goveralls
+  - go get golang.org/x/tools/cmd/cover
   - go get -u github.com/golang/lint/golint
+
 script:
-  - test -z "$(gofmt -s -l -w . | tee /dev/stderr)"
-  - test -z "$(golint . | tee /dev/stderr)"
-  - go vet -v .
-  - go test -v -cover  ./...
+  - go vet -x ./...
+  - golint ./...
+  - go test -v  ./...
+  - go test -covermode=count -coverprofile=profile.cov
+
+after_script:
+  - goveralls -coverprofile=profile.cov -service=travis-ci

LICENSE

@@ -1,14 +1,21 @@
-Copyright 2013 Ahmet Alp Balkan
+The MIT License (MIT)
 
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
+Copyright (c) 2016 Alexander Kalankhodzhaev
 
-     http://www.apache.org/licenses/LICENSE-2.0
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
 
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

aggregate.go

@@ -0,0 +1,53 @@
+package linq
+
+// Aggregate applies an accumulator function over a sequence.
+//
+// Aggregate method makes it simple to perform a calculation over a sequence of values.
+// This method works by calling f() one time for each element in source
+// except the first one. Each time f() is called, Aggregate passes both
+// the element from the sequence and an aggregated value (as the first argument to f()).
+// The first element of source is used as the initial aggregate value.
+// The result of f() replaces the previous aggregated value.
+//
+// Aggregate returns the final result of f().
+func (q Query) Aggregate(
+	f func(interface{}, interface{}) interface{}) interface{} {
+	next := q.Iterate()
+
+	result, any := next()
+	if !any {
+		return nil
+	}
+
+	for current, ok := next(); ok; current, ok = next() {
+		result = f(result, current)
+	}
+
+	return result
+}
+
+// AggregateWithSeed applies an accumulator function over a sequence.
+// The specified seed value is used as the initial accumulator value.
+//
+// Aggregate method makes it simple to perform a calculation over a sequence of values.
+// This method works by calling f() one time for each element in source
+// except the first one. Each time f() is called, Aggregate passes both
+// the element from the sequence and an aggregated value (as the first argument to f()).
+// The value of the seed parameter is used as the initial aggregate value.
+// The result of f() replaces the previous aggregated value.
+//
+// Aggregate returns the final result of f().
+func (q Query) AggregateWithSeed(
+	seed interface{},
+	f func(interface{}, interface{}) interface{},
+) interface{} {
+
+	next := q.Iterate()
+	result := seed
+
+	for current, ok := next(); ok; current, ok = next() {
+		result = f(result, current)
+	}
+
+	return result
+}

aggregate_test.go

@@ -0,0 +1,43 @@
+package linq
+
+import "testing"
+
+func TestAggregate(t *testing.T) {
+	tests := []struct {
+		input interface{}
+		want  interface{}
+	}{
+		{[]string{"apple", "mango", "orange", "passionfruit", "grape"}, "passionfruit"},
+		{[]string{}, nil},
+	}
+
+	for _, test := range tests {
+		r := From(test.input).Aggregate(func(r interface{}, i interface{}) interface{} {
+			if len(r.(string)) > len(i.(string)) {
+				return r
+			}
+			return i
+		})
+
+		if r != test.want {
+			t.Errorf("From(%v).Aggregate()=%v expected %v", test.input, r, test.want)
+		}
+	}
+}
+
+func TestAggregateWithSeed(t *testing.T) {
+	input := []string{"apple", "mango", "orange", "banana", "grape"}
+	want := "passionfruit"
+
+	r := From(input).AggregateWithSeed(want,
+		func(r interface{}, i interface{}) interface{} {
+			if len(r.(string)) > len(i.(string)) {
+				return r
+			}
+			return i
+		})
+
+	if r != want {
+		t.Errorf("From(%v).AggregateWithSeed()=%v expected %v", input, r, want)
+	}
+}