deploy: 06a1bdf735

vendor/gopl.io/ch2/tempconv0/celsius.go

@@ -0,0 +1,27 @@
+// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+// See page 39.
+//!+
+
+// Package tempconv performs Celsius and Fahrenheit temperature computations.
+package tempconv
+
+import "fmt"
+
+type Celsius float64
+type Fahrenheit float64
+
+const (
+	AbsoluteZeroC Celsius = -273.15
+	FreezingC     Celsius = 0
+	BoilingC      Celsius = 100
+)
+
+func CToF(c Celsius) Fahrenheit { return Fahrenheit(c*9/5 + 32) }
+
+func FToC(f Fahrenheit) Celsius { return Celsius((f - 32) * 5 / 9) }
+
+//!-
+
+func (c Celsius) String() string { return fmt.Sprintf("%g°C", c) }

vendor/gopl.io/ch2/tempconv0/tempconv_test.go

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+// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+package tempconv
+
+import "fmt"
+
+func Example_one() {
+	{
+		//!+arith
+		fmt.Printf("%g\n", BoilingC-FreezingC) // "100" °C
+		boilingF := CToF(BoilingC)
+		fmt.Printf("%g\n", boilingF-CToF(FreezingC)) // "180" °F
+		//!-arith
+	}
+	/*
+		//!+arith
+		fmt.Printf("%g\n", boilingF-FreezingC)       // compile error: type mismatch
+		//!-arith
+	*/
+
+	// Output:
+	// 100
+	// 180
+}
+
+func Example_two() {
+	//!+printf
+	c := FToC(212.0)
+	fmt.Println(c.String()) // "100°C"
+	fmt.Printf("%v\n", c)   // "100°C"; no need to call String explicitly
+	fmt.Printf("%s\n", c)   // "100°C"
+	fmt.Println(c)          // "100°C"
+	fmt.Printf("%g\n", c)   // "100"; does not call String
+	fmt.Println(float64(c)) // "100"; does not call String
+	//!-printf
+
+	// Output:
+	// 100°C
+	// 100°C
+	// 100°C
+	// 100°C
+	// 100
+	// 100
+}