Add docs for GOPATH and GOROOT

src/go/go.rst

@@ -1,5 +1,5 @@
-Go
-====
+Go-Lang
+=======
 
 
 Contents:
@@ -8,5 +8,4 @@ Contents:
    :maxdepth: 2
 
    tips
-   intro
 

src/go/intro.rst

@@ -1,78 +0,0 @@
-Introduction to go programming language
-=======================================
-
-Builtin function
-----------------
-
-
-
-
-Define slice
-------------
-
-.. code-block:: go
-
-    package main
-
-    import "fmt"
-
-    func main() {
-
-        var slice_1 []int
-        slice_2 := []int {}
-        slice_3 := make([]int, 0)
-
-        var slice_4 = []int  {1, 2, 3, 4}
-        slice_5 := []int {1, 2, 3, 4}
-
-        slice_6 := make([]int, 0)
-        slice_6 = append(slice_6, 1, 2, 3, 4)
-
-        slice_7 := slice_4[:]
-        slice_8 := slice_5[0:4]
-
-        slice_9 := make([]int, 4) // [0 0 0 0]
-        copy(slice_9, slice_4)
-
-        fmt.Println(slice_1, slice_2, slice_3, slice_4, slice_5, slice_6, slice_7, slice_8, slice_9)
-    }
-    // [] [] [] [1 2 3 4] [1 2 3 4] [1 2 3 4] [1 2 3 4] [1 2 3 4] [1 2 3 4]
-
-Notes:
-
-*   The first argument of ``make``, ``append`` and ``copy`` functions must be slice.
-
-*   The second argument of ``copy`` function also must be slice. (As a special case, it also will copy bytes from a string to a slice of bytes.)
-
-*   The ``copy`` function returns the number of elements copied, which will be the minimum of len(src) and len(dst).
-
-
-.. code-block:: go
-
-    package main
-
-    import "fmt"
-
-    func main() {
-
-        slice_1 := []int {1, 2, 3, 4, 5}
-        slice_2 := []int {11, 22}
-        slice_3 := []int {111}
-        slice_4 := []int {}
-
-        count := copy(slice_1, slice_2)
-        fmt.Println(count, slice_1)
-
-        count = copy(slice_3, slice_2)
-        fmt.Println(count, slice_3)
-
-        count = copy(slice_4, slice_2)
-        fmt.Println(count, slice_4)
-
-    }
-    // 2 [11 22 3 4 5]
-    // 1 [11]
-    // 0 []
-
-
-

src/go/tips.rst

@@ -2,4 +2,94 @@ Tips
 ====
 
 
+Builtin function
+----------------
+
 http://golang.org/pkg/builtin/
+
+
+Introduction to go programming language
+---------------------------------------
+
+
+Define slice
+++++++++++++
+
+
+.. code-block:: go
+
+    package main
+
+    import "fmt"
+
+    func main() {
+
+        var slice_1 []int
+        slice_2 := []int {}
+        slice_3 := make([]int, 0)
+
+        var slice_4 = []int  {1, 2, 3, 4}
+        slice_5 := []int {1, 2, 3, 4}
+
+        slice_6 := make([]int, 0)
+        slice_6 = append(slice_6, 1, 2, 3, 4)
+
+        slice_7 := slice_4[:]
+        slice_8 := slice_5[0:4]
+
+        slice_9 := make([]int, 4) // [0 0 0 0]
+        copy(slice_9, slice_4)
+
+        fmt.Println(slice_1, slice_2, slice_3, slice_4, slice_5, slice_6, slice_7, slice_8, slice_9)
+    }
+    // [] [] [] [1 2 3 4] [1 2 3 4] [1 2 3 4] [1 2 3 4] [1 2 3 4] [1 2 3 4]
+
+Notes:
+
+*   The first argument of ``make``, ``append`` and ``copy`` functions must be slice.
+
+*   The second argument of ``copy`` function also must be slice. (As a special case, it also will copy bytes from a string to a slice of bytes.)
+
+*   The ``copy`` function returns the number of elements copied, which will be the minimum of len(src) and len(dst).
+
+
+.. code-block:: go
+
+    package main
+
+    import "fmt"
+
+    func main() {
+
+        slice_1 := []int {1, 2, 3, 4, 5}
+        slice_2 := []int {11, 22}
+        slice_3 := []int {111}
+        slice_4 := []int {}
+
+        count := copy(slice_1, slice_2)
+        fmt.Println(count, slice_1)
+
+        count = copy(slice_3, slice_2)
+        fmt.Println(count, slice_3)
+
+        count = copy(slice_4, slice_2)
+        fmt.Println(count, slice_4)
+
+    }
+    // 2 [11 22 3 4 5]
+    // 1 [11]
+    // 0 []
+
+
+
+SET the GOPATH and GOROOT environments
+--------------------------------------
+
+.. code-block:: bash
+
+    $ export GOROOT=/usr/lib/go
+    $ export GOPATH=$HOME/go
+    $ export PATH=$PATH:$GOROOT/bin:$GOPATH/bin
+
+
+https://stackoverflow.com/a/43553857