fix import of io/ioutil, run gofmt

generated/downloaded file doesn't work with "go run". it's missing ioutil.
ran gofmt which uses tabs (width=8) for formatting. longest line is 85
characters now. removed whitespace.

1 files changed, 225 insertions, 224 deletions

diff --git a/go.html.markdown b/go.html.markdown
index 0ecc6120..a1be08af 100644
--- a/go.html.markdown
+++ b/go.html.markdown
@@ -9,6 +9,7 @@ contributors:
     - ["Jesse Johnson", "https://github.com/holocronweaver"]
     - ["Quint Guvernator", "https://github.com/qguv"]
     - ["Jose Donizetti", "https://github.com/josedonizetti"]
+    - ["Alexej Friesen", "https://github.com/heyalexej"]
 ---
 
 Go was created out of the need to get work done.  It's not the latest trend
@@ -33,87 +34,88 @@ package main
 
 // Import declaration declares library packages referenced in this file.
 import (
-    "fmt"      // A package in the Go standard library.
-    "net/http" // Yes, a web server!
-    "strconv"  // String conversions.
-    m "math"   // Math library with local alias m.
+	"fmt"       // A package in the Go standard library.
+	"io/ioutil" // Implements some I/O utility functions.
+	m "math"    // Math library with local alias m.
+	"net/http"  // Yes, a web server!
+	"strconv"   // String conversions.
 )
 
 // A function definition.  Main is special.  It is the entry point for the
 // executable program.  Love it or hate it, Go uses brace brackets.
 func main() {
-    // Println outputs a line to stdout.
-    // Qualify it with the package name, fmt.
-    fmt.Println("Hello world!")
+	// Println outputs a line to stdout.
+	// Qualify it with the package name, fmt.
+	fmt.Println("Hello world!")
 
-    // Call another function within this package.
-    beyondHello()
+	// Call another function within this package.
+	beyondHello()
 }
 
 // Functions have parameters in parentheses.
 // If there are no parameters, empty parentheses are still required.
 func beyondHello() {
-    var x int // Variable declaration.  Variables must be declared before use.
-    x = 3     // Variable assignment.
-    // "Short" declarations use := to infer the type, declare, and assign.
-    y := 4
-    sum, prod := learnMultiple(x, y)        // Function returns two values.
-    fmt.Println("sum:", sum, "prod:", prod) // Simple output.
-    learnTypes()                            // < y minutes, learn more!
+	var x int // Variable declaration. Variables must be declared before use.
+	x = 3     // Variable assignment.
+	// "Short" declarations use := to infer the type, declare, and assign.
+	y := 4
+	sum, prod := learnMultiple(x, y)        // Function returns two values.
+	fmt.Println("sum:", sum, "prod:", prod) // Simple output.
+	learnTypes()                            // < y minutes, learn more!
 }
 
 // Functions can have parameters and (multiple!) return values.
 func learnMultiple(x, y int) (sum, prod int) {
-    return x + y, x * y // Return two values.
+	return x + y, x * y // Return two values.
 }
 
 // Some built-in types and literals.
 func learnTypes() {
-    // Short declaration usually gives you what you want.
-    s := "Learn Go!" // string type.
+	// Short declaration usually gives you what you want.
+	s := "Learn Go!" // string type.
 
-    s2 := `A "raw" string literal
+	s2 := `A "raw" string literal
 can include line breaks.` // Same string type.
 
-    // Non-ASCII literal.  Go source is UTF-8.
-    g := 'Σ' // rune type, an alias for uint32, holds a unicode code point.
+	// Non-ASCII literal.  Go source is UTF-8.
+	g := 'Σ' // rune type, an alias for uint32, holds a unicode code point.
 
-    f := 3.14195 // float64, an IEEE-754 64-bit floating point number.
-    c := 3 + 4i  // complex128, represented internally with two float64's.
+	f := 3.14195 // float64, an IEEE-754 64-bit floating point number.
+	c := 3 + 4i  // complex128, represented internally with two float64's.
 
-    // Var syntax with an initializers.
-    var u uint = 7 // Unsigned, but implementation dependent size as with int.
-    var pi float32 = 22. / 7
+	// Var syntax with an initializers.
+	var u uint = 7 // Unsigned, but implementation dependent size as with int.
+	var pi float32 = 22. / 7
 
-    // Conversion syntax with a short declaration.
-    n := byte('\n') // byte is an alias for uint8.
+	// Conversion syntax with a short declaration.
+	n := byte('\n') // byte is an alias for uint8.
 
-    // Arrays have size fixed at compile time.
-    var a4 [4]int           // An array of 4 ints, initialized to all 0.
-    a3 := [...]int{3, 1, 5} // An array of 3 ints, initialized as shown.
+	// Arrays have size fixed at compile time.
+	var a4 [4]int           // An array of 4 ints, initialized to all 0.
+	a3 := [...]int{3, 1, 5} // An array of 3 ints, initialized as shown.
 
-    // Slices have dynamic size.  Arrays and slices each have advantages
-    // but use cases for slices are much more common.
-    s3 := []int{4, 5, 9}    // Compare to a3.  No ellipsis here.
-    s4 := make([]int, 4)    // Allocates slice of 4 ints, initialized to all 0.
-    var d2 [][]float64      // Declaration only, nothing allocated here.
-    bs := []byte("a slice") // Type conversion syntax.
+	// Slices have dynamic size.  Arrays and slices each have advantages
+	// but use cases for slices are much more common.
+	s3 := []int{4, 5, 9}    // Compare to a3.  No ellipsis here.
+	s4 := make([]int, 4)    // Allocates slice of 4 ints, initialized to all 0.
+	var d2 [][]float64      // Declaration only, nothing allocated here.
+	bs := []byte("a slice") // Type conversion syntax.
 
-    p, q := learnMemory() // Declares p, q to be type pointer to int.
-    fmt.Println(*p, *q)   // * follows a pointer.  This prints two ints.
+	p, q := learnMemory() // Declares p, q to be type pointer to int.
+	fmt.Println(*p, *q)   // * follows a pointer.  This prints two ints.
 
-    // Maps are a dynamically growable associative array type, like the
-    // hash or dictionary types of some other languages.
-    m := map[string]int{"three": 3, "four": 4}
-    m["one"] = 1
+	// Maps are a dynamically growable associative array type, like the
+	// hash or dictionary types of some other languages.
+	m := map[string]int{"three": 3, "four": 4}
+	m["one"] = 1
 
-    // Unused variables are an error in Go.
-    // The underbar lets you "use" a variable but discard its value.
-    _, _, _, _, _, _, _, _, _ = s2, g, f, u, pi, n, a3, s4, bs
-    // Output of course counts as using a variable.
-    fmt.Println(s, c, a4, s3, d2, m)
+	// Unused variables are an error in Go.
+	// The underbar lets you "use" a variable but discard its value.
+	_, _, _, _, _, _, _, _, _ = s2, g, f, u, pi, n, a3, s4, bs
+	// Output of course counts as using a variable.
+	fmt.Println(s, c, a4, s3, d2, m)
 
-    learnFlowControl() // Back in the flow.
+	learnFlowControl() // Back in the flow.
 }
 
 // It is possible, unlike in many other languages for functions in go
@@ -122,250 +124,249 @@ can include line breaks.` // Same string type.
 // allows us to easily return from multiple points in a function as well as to
 // only use the return keyword, without anything further.
 func learnNamedReturns(x, y int) (z int) {
-    z = x * y
-    return              // z is implicit here, because we named it earlier.
+	z = x * y
+	return // z is implicit here, because we named it earlier.
 }
 
 // Go is fully garbage collected.  It has pointers but no pointer arithmetic.
 // You can make a mistake with a nil pointer, but not by incrementing a pointer.
 func learnMemory() (p, q *int) {
-    // Named return values p and q have type pointer to int.
-    p = new(int) // Built-in function new allocates memory.
-    // The allocated int is initialized to 0, p is no longer nil.
-    s := make([]int, 20) // Allocate 20 ints as a single block of memory.
-    s[3] = 7             // Assign one of them.
-    r := -2              // Declare another local variable.
-    return &s[3], &r     // & takes the address of an object.
+	// Named return values p and q have type pointer to int.
+	p = new(int) // Built-in function new allocates memory.
+	// The allocated int is initialized to 0, p is no longer nil.
+	s := make([]int, 20) // Allocate 20 ints as a single block of memory.
+	s[3] = 7             // Assign one of them.
+	r := -2              // Declare another local variable.
+	return &s[3], &r     // & takes the address of an object.
 }
 
 func expensiveComputation() float64 {
-    return m.Exp(10)
+	return m.Exp(10)
 }
 
 func learnFlowControl() {
-    // If statements require brace brackets, and do not require parens.
-    if true {
-        fmt.Println("told ya")
-    }
-    // Formatting is standardized by the command line command "go fmt."
-    if false {
-        // Pout.
-    } else {
-        // Gloat.
-    }
-    // Use switch in preference to chained if statements.
-    x := 42.0
-    switch x {
-    case 0:
-    case 1:
-    case 42:
-        // Cases don't "fall through".
-    case 43:
-        // Unreached.
-    }
-    // Like if, for doesn't use parens either.
-    // Variables declared in for and if are local to their scope.
-    for x := 0; x < 3; x++ { // ++ is a statement.
-        fmt.Println("iteration", x)
-    }
-    // x == 42 here.
-
-    // For is the only loop statement in Go, but it has alternate forms.
-    for { // Infinite loop.
-        break    // Just kidding.
-        continue // Unreached.
-    }
-    // As with for, := in an if statement means to declare and assign y first,
-    // then test y > x.
-    if y := expensiveComputation(); y > x {
-        x = y
-    }
-    // Function literals are closures.
-    xBig := func() bool {
-        return x > 10000 // References x declared above switch statement.
-    }
-    fmt.Println("xBig:", xBig()) // true (we last assigned e^10 to x).
-    x = 1.3e3                    // This makes x == 1300
-    fmt.Println("xBig:", xBig()) // false now.
-
-    // What's more is function literals may be defined and called inline,
-    // acting as an argument to function, as long as:
-    // a) function literal is called immediately (),
-    // b) result type matches expected type of argument.
-    fmt.Println("Add + double two numbers: ",
-        func(a, b int) int {
-	    return (a + b) * 2 
-	    }(10, 2)) // Called with args 10 and 2
-    // => Add + double two numbers:  24
-	    
-    // When you need it, you'll love it.
-    goto love
+	// If statements require brace brackets, and do not require parens.
+	if true {
+		fmt.Println("told ya")
+	}
+	// Formatting is standardized by the command line command "go fmt."
+	if false {
+		// Pout.
+	} else {
+		// Gloat.
+	}
+	// Use switch in preference to chained if statements.
+	x := 42.0
+	switch x {
+	case 0:
+	case 1:
+	case 42:
+		// Cases don't "fall through".
+	case 43:
+		// Unreached.
+	}
+	// Like if, for doesn't use parens either.
+	// Variables declared in for and if are local to their scope.
+	for x := 0; x < 3; x++ { // ++ is a statement.
+		fmt.Println("iteration", x)
+	}
+	// x == 42 here.
+
+	// For is the only loop statement in Go, but it has alternate forms.
+	for { // Infinite loop.
+		break    // Just kidding.
+		continue // Unreached.
+	}
+	// As with for, := in an if statement means to declare and assign
+	// y first, then test y > x.
+	if y := expensiveComputation(); y > x {
+		x = y
+	}
+	// Function literals are closures.
+	xBig := func() bool {
+		return x > 10000 // References x declared above switch statement.
+	}
+	fmt.Println("xBig:", xBig()) // true (we last assigned e^10 to x).
+	x = 1.3e3                    // This makes x == 1300
+	fmt.Println("xBig:", xBig()) // false now.
+
+	// What's more is function literals may be defined and called inline,
+	// acting as an argument to function, as long as:
+	// a) function literal is called immediately (),
+	// b) result type matches expected type of argument.
+	fmt.Println("Add + double two numbers: ",
+		func(a, b int) int {
+			return (a + b) * 2
+		}(10, 2)) // Called with args 10 and 2
+	// => Add + double two numbers:  24
+
+	// When you need it, you'll love it.
+	goto love
 love:
 
-    learnFunctionFactory() // func returning func is fun(3)(3)
-    learnDefer() // A quick detour to an important keyword.
-    learnInterfaces() // Good stuff coming up!
+	learnFunctionFactory() // func returning func is fun(3)(3)
+	learnDefer()      // A quick detour to an important keyword.
+	learnInterfaces() // Good stuff coming up!
 }
 
 func learnFunctionFactory() {
-    // Next two are equivalent, with second being more practical
-    fmt.Println(sentenceFactory("summer")("A beautiful", "day!"))
+	// Next two are equivalent, with second being more practical
+	fmt.Println(sentenceFactory("summer")("A beautiful", "day!"))
 
-    d := sentenceFactory("summer")
-    fmt.Println(d("A beautiful", "day!"))
-    fmt.Println(d("A lazy", "afternoon!"))
+	d := sentenceFactory("summer")
+	fmt.Println(d("A beautiful", "day!"))
+	fmt.Println(d("A lazy", "afternoon!"))
 }
 
 // Decorators are common in other languages. Same can be done in Go
 // with function literals that accept arguments.
 func sentenceFactory(mystring string) func(before, after string) string {
-    return func(before, after string) string {
-        return fmt.Sprintf("%s %s %s", before, mystring, after) // new string
-    }
+	return func(before, after string) string {
+		return fmt.Sprintf("%s %s %s", before, mystring, after) // new string
+	}
 }
 
 func learnDefer() (ok bool) {
-    // Deferred statements are executed just before the function returns.
-    defer fmt.Println("deferred statements execute in reverse (LIFO) order.")
-    defer fmt.Println("\nThis line is being printed first because")
-    // Defer is commonly used to close a file, so the function closing the file
-    // stays close to the function opening the file
-    return true
+	// Deferred statements are executed just before the function returns.
+	defer fmt.Println("deferred statements execute in reverse (LIFO) order.")
+	defer fmt.Println("\nThis line is being printed first because")
+	// Defer is commonly used to close a file, so the function closing the
+	// file stays close to the function opening the file.
+	return true
 }
 
 // Define Stringer as an interface type with one method, String.
 type Stringer interface {
-    String() string
+	String() string
 }
 
 // Define pair as a struct with two fields, ints named x and y.
 type pair struct {
-    x, y int
+	x, y int
 }
 
 // Define a method on type pair.  Pair now implements Stringer.
 func (p pair) String() string { // p is called the "receiver"
-    // Sprintf is another public function in package fmt.
-    // Dot syntax references fields of p.
-    return fmt.Sprintf("(%d, %d)", p.x, p.y)
+	// Sprintf is another public function in package fmt.
+	// Dot syntax references fields of p.
+	return fmt.Sprintf("(%d, %d)", p.x, p.y)
 }
 
 func learnInterfaces() {
-    // Brace syntax is a "struct literal."  It evaluates to an initialized
-    // struct.  The := syntax declares and initializes p to this struct.
-    p := pair{3, 4}
-    fmt.Println(p.String()) // Call String method of p, of type pair.
-    var i Stringer          // Declare i of interface type Stringer.
-    i = p                   // Valid because pair implements Stringer
-    // Call String method of i, of type Stringer.  Output same as above.
-    fmt.Println(i.String())
-
-    // Functions in the fmt package call the String method to ask an object
-    // for a printable representation of itself.
-    fmt.Println(p) // Output same as above. Println calls String method.
-    fmt.Println(i) // Output same as above.
-
-    learnVariadicParams("great", "learning", "here!")
+	// Brace syntax is a "struct literal."  It evaluates to an initialized
+	// struct.  The := syntax declares and initializes p to this struct.
+	p := pair{3, 4}
+	fmt.Println(p.String()) // Call String method of p, of type pair.
+	var i Stringer          // Declare i of interface type Stringer.
+	i = p                   // Valid because pair implements Stringer
+	// Call String method of i, of type Stringer.  Output same as above.
+	fmt.Println(i.String())
+
+	// Functions in the fmt package call the String method to ask an object
+	// for a printable representation of itself.
+	fmt.Println(p) // Output same as above. Println calls String method.
+	fmt.Println(i) // Output same as above.
+
+	learnVariadicParams("great", "learning", "here!")
 }
 
 // Functions can have variadic parameters.
 func learnVariadicParams(myStrings ...interface{}) {
-    // Iterate each value of the variadic.
-    // The underbar here is ignoring the index argument of the array.
-    for _, param := range myStrings {
-        fmt.Println("param:", param)
-    }
+	// Iterate each value of the variadic.
+	// The underbar here is ignoring the index argument of the array.
+	for _, param := range myStrings {
+		fmt.Println("param:", param)
+	}
 
-    // Pass variadic value as a variadic parameter.
-    fmt.Println("params:", fmt.Sprintln(myStrings...))
+	// Pass variadic value as a variadic parameter.
+	fmt.Println("params:", fmt.Sprintln(myStrings...))
 
-    learnErrorHandling()
+	learnErrorHandling()
 }
 
 func learnErrorHandling() {
-    // ", ok" idiom used to tell if something worked or not.
-    m := map[int]string{3: "three", 4: "four"}
-    if x, ok := m[1]; !ok { // ok will be false because 1 is not in the map.
-        fmt.Println("no one there")
-    } else {
-        fmt.Print(x) // x would be the value, if it were in the map.
-    }
-    // An error value communicates not just "ok" but more about the problem.
-    if _, err := strconv.Atoi("non-int"); err != nil { // _ discards value
-        // prints 'strconv.ParseInt: parsing "non-int": invalid syntax'
-        fmt.Println(err)
-    }
-    // We'll revisit interfaces a little later.  Meanwhile,
-    learnConcurrency()
+	// ", ok" idiom used to tell if something worked or not.
+	m := map[int]string{3: "three", 4: "four"}
+	if x, ok := m[1]; !ok { // ok will be false because 1 is not in the map.
+		fmt.Println("no one there")
+	} else {
+		fmt.Print(x) // x would be the value, if it were in the map.
+	}
+	// An error value communicates not just "ok" but more about the problem.
+	if _, err := strconv.Atoi("non-int"); err != nil { // _ discards value
+		// prints 'strconv.ParseInt: parsing "non-int": invalid syntax'
+		fmt.Println(err)
+	}
+	// We'll revisit interfaces a little later.  Meanwhile,
+	learnConcurrency()
 }
 
 // c is a channel, a concurrency-safe communication object.
 func inc(i int, c chan int) {
-    c <- i + 1 // <- is the "send" operator when a channel appears on the left.
+	c <- i + 1 // <- is the "send" operator when a channel appears on the left.
 }
 
 // We'll use inc to increment some numbers concurrently.
 func learnConcurrency() {
-    // Same make function used earlier to make a slice.  Make allocates and
-    // initializes slices, maps, and channels.
-    c := make(chan int)
-    // Start three concurrent goroutines.  Numbers will be incremented
-    // concurrently, perhaps in parallel if the machine is capable and
-    // properly configured.  All three send to the same channel.
-    go inc(0, c) // go is a statement that starts a new goroutine.
-    go inc(10, c)
-    go inc(-805, c)
-    // Read three results from the channel and print them out.
-    // There is no telling in what order the results will arrive!
-    fmt.Println(<-c, <-c, <-c) // channel on right, <- is "receive" operator.
-
-    cs := make(chan string)       // Another channel, this one handles strings.
-    ccs := make(chan chan string) // A channel of string channels.
-    go func() { c <- 84 }()       // Start a new goroutine just to send a value.
-    go func() { cs <- "wordy" }() // Again, for cs this time.
-    // Select has syntax like a switch statement but each case involves
-    // a channel operation.  It selects a case at random out of the cases
-    // that are ready to communicate.
-    select {
-    case i := <-c: // The value received can be assigned to a variable,
-        fmt.Printf("it's a %T", i)
-    case <-cs:     // or the value received can be discarded.
-        fmt.Println("it's a string")
-    case <-ccs:    // Empty channel, not ready for communication.
-        fmt.Println("didn't happen.")
-    }
-    // At this point a value was taken from either c or cs.  One of the two
-    // goroutines started above has completed, the other will remain blocked.
-
-    learnWebProgramming() // Go does it. You want to do it too.
+	// Same make function used earlier to make a slice.  Make allocates and
+	// initializes slices, maps, and channels.
+	c := make(chan int)
+	// Start three concurrent goroutines.  Numbers will be incremented
+	// concurrently, perhaps in parallel if the machine is capable and
+	// properly configured.  All three send to the same channel.
+	go inc(0, c) // go is a statement that starts a new goroutine.
+	go inc(10, c)
+	go inc(-805, c)
+	// Read three results from the channel and print them out.
+	// There is no telling in what order the results will arrive!
+	fmt.Println(<-c, <-c, <-c) // channel on right, <- is "receive" operator.
+
+	cs := make(chan string)       // Another channel, this one handles strings.
+	ccs := make(chan chan string) // A channel of string channels.
+	go func() { c <- 84 }()       // Start a new goroutine just to send a value.
+	go func() { cs <- "wordy" }() // Again, for cs this time.
+	// Select has syntax like a switch statement but each case involves
+	// a channel operation.  It selects a case at random out of the cases
+	// that are ready to communicate.
+	select {
+	case i := <-c: // The value received can be assigned to a variable,
+		fmt.Printf("it's a %T", i)
+	case <-cs: // or the value received can be discarded.
+		fmt.Println("it's a string")
+	case <-ccs: // Empty channel, not ready for communication.
+		fmt.Println("didn't happen.")
+	}
+	// At this point a value was taken from either c or cs.  One of the two
+	// goroutines started above has completed, the other will remain blocked.
+
+	learnWebProgramming() // Go does it. You want to do it too.
 }
 
 // A single function from package http starts a web server.
 func learnWebProgramming() {
 
-    // First parameter of ListenAndServe is TCP address to listen to.
-    // Second parameter is an interface, specifically http.Handler.
-    go func() {
-        err := http.ListenAndServe(":8080", pair{})
-        fmt.Println(err) // don't ignore errors
-    }()
+	// First parameter of ListenAndServe is TCP address to listen to.
+	// Second parameter is an interface, specifically http.Handler.
+	go func() {
+		err := http.ListenAndServe(":8080", pair{})
+		fmt.Println(err) // don't ignore errors
+	}()
 
-    requestServer();
+	requestServer()
 }
 
-
 // Make pair an http.Handler by implementing its only method, ServeHTTP.
 func (p pair) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-    // Serve data with a method of http.ResponseWriter.
-    w.Write([]byte("You learned Go in Y minutes!"))
+	// Serve data with a method of http.ResponseWriter.
+	w.Write([]byte("You learned Go in Y minutes!"))
 }
 
 func requestServer() {
-    resp, err := http.Get("http://localhost:8080")
-    fmt.Println(err)
-    defer resp.Body.Close()
-    body, err := ioutil.ReadAll(resp.Body)
-    fmt.Printf("\nWebserver said: `%s`", string(body))
+	resp, err := http.Get("http://localhost:8080")
+	fmt.Println(err)
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	fmt.Printf("\nWebserver said: `%s`", string(body))
 }
 ```