Feature/add converters and bitwise ops (#20)

* added:

- converters
- bitwise operators
- hex input and output support

calc.go

@@ -62,6 +62,8 @@ const Help string = `
 Operators:
 basic operators: + - x * / ^  (* is an alias of x)
 
+Bitwise operators: and or xor < (left shift) > (right shift)
+
 Percent functions:
 %                    percent
 %-                   substract percent
@@ -235,6 +237,15 @@ func (c *Calc) Eval(line string) {
 			c.stack.Backup()
 			c.stack.Push(num)
 		} else {
+			// try hex
+			var i int
+			_, err := fmt.Sscanf(item, "0x%x", &i)
+			if err == nil {
+				c.stack.Backup()
+				c.stack.Push(float64(i))
+				continue
+			}
+
 			if contains(c.Constants, item) {
 				// put the constant onto the stack
 				c.stack.Backup()

calc_test.go

@@ -241,6 +241,45 @@ func TestCalc(t *testing.T) {
 			cmd:  `4 4 + undo *`,
 			exp:  16,
 		},
+
+		// bit tests
+		{
+			name: "bit and",
+			cmd:  `1 3 and`,
+			exp:  1,
+		},
+		{
+			name: "bit or",
+			cmd:  `1 3 or`,
+			exp:  3,
+		},
+		{
+			name: "bit xor",
+			cmd:  `1 3 xor`,
+			exp:  2,
+		},
+
+		// converters
+		{
+			name: "inch-to-cm",
+			cmd:  `111 inch-to-cm`,
+			exp:  281.94,
+		},
+		{
+			name: "gallons-to-liters",
+			cmd:  `111 gallons-to-liters`,
+			exp:  420.135,
+		},
+		{
+			name: "meters-to-yards",
+			cmd:  `111 meters-to-yards`,
+			exp:  1.2139107611548556,
+		},
+		{
+			name: "miles-to-kilometers",
+			cmd:  `111 miles-to-kilometers`,
+			exp:  178.599,
+		},
 	}
 
 	for _, tt := range tests {

command.go

@@ -117,6 +117,15 @@ func (c *Calc) SetCommands() {
 				}
 			},
 		),
+
+		"hex": NewCommand(
+			"show last stack item in hex form (converted to int)",
+			func(c *Calc) {
+				if c.stack.Len() > 0 {
+					fmt.Printf("0x%x\n", int(c.stack.Last()[0]))
+				}
+			},
+		),
 	}
 
 	c.StackCommands = Commands{

funcs.go

@@ -387,6 +387,85 @@ func DefineFunctions() Funcalls {
 				return NewR(math.Hypot(arg[0], arg[1]), nil)
 			},
 			2),
+
+		// converters of all kinds
+		"cm-to-inch": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]/2.54, nil)
+			},
+			1),
+
+		"inch-to-cm": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]*2.54, nil)
+			},
+			1),
+
+		"gallons-to-liters": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]*3.785, nil)
+			},
+			1),
+
+		"liters-to-gallons": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]/3.785, nil)
+			},
+			1),
+
+		"yards-to-meters": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]*91.44, nil)
+			},
+			1),
+
+		"meters-to-yards": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]/91.44, nil)
+			},
+			1),
+
+		"miles-to-kilometers": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]*1.609, nil)
+			},
+			1),
+
+		"kilometers-to-miles": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(arg[0]/1.609, nil)
+			},
+			1),
+
+		"or": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(float64(int(arg[0])|int(arg[1])), nil)
+			},
+			2),
+
+		"and": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(float64(int(arg[0])&int(arg[1])), nil)
+			},
+			2),
+
+		"xor": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(float64(int(arg[0])^int(arg[1])), nil)
+			},
+			2),
+
+		"<": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(float64(int(arg[0])<<int(arg[1])), nil)
+			},
+			2),
+
+		">": NewFuncall(
+			func(arg Numbers) R {
+				return NewR(float64(int(arg[0])>>int(arg[1])), nil)
+			},
+			2),
 	}
 
 	// aliases

main.go

@@ -30,7 +30,7 @@ import (
 	lua "github.com/yuin/gopher-lua"
 )
 
-const VERSION string = "2.0.9"
+const VERSION string = "2.0.10"
 
 const Usage string = `This is rpn, a reverse polish notation calculator cli.
 

rpn.go

@@ -105,6 +105,9 @@ DESCRIPTION
     If the first parameter to rpn is a math operator or function, batch mode
     is enabled automatically, see last example.
 
+    You can enter integers, floating point numbers (positive or negative) or
+    hex numbers (prefixed with 0x).
+
   STACK MANIPULATION
     There are lots of stack manipulation commands provided. The most
     important one is undo which goes back to the stack before the last math

rpn.pod

@@ -109,6 +109,9 @@ Example of batch mode usage:
 If the first parameter to rpn is a math operator or function, batch
 mode is enabled automatically, see last example.
 
+You can enter integers, floating  point numbers (positive or negative)
+or hex numbers (prefixed with 0x).
+
 =head2 STACK MANIPULATION
 
 There are lots of stack manipulation commands provided. The most
@@ -136,6 +139,14 @@ Basic operators:
     x                    multiply (alias: *)
     ^                    power
 
+Bitwise operators:
+
+    and                  bitwise and
+    or                   bitwise or
+    xor                  bitwise xor
+    <                    left shift
+    >                    right shift
+
 Percent functions:
 
     %                    percent
@@ -157,19 +168,40 @@ Math functions:
     log10 log1p log2 logb pow round roundtoeven sin sinh tan tanh trunc y0
     y1 copysign dim hypot
 
-Commands:
+Conversion functions:
+
+    cm-to-inch
+    inch-to-cm
+    gallons-to-liters
+    liters-to-gallons
+    yards-to-meters
+    meters-to-yards
+    miles-to-kilometers
+    kilometers-to-miles
+
+Configuration Commands:
 
     [no]batch            toggle batch mode (nobatch turns it off)
     [no]debug            toggle debug output (nodebug turns it off)
     [no]showstack        show the last 5 items of the stack (noshowtack turns it off)
+
+Show commands:
     dump                 display the stack contents
+    hex                  show last stack item in hex form (converted to int)
+    history              display calculation history
+    vars                 show list of variables
+
+Stack manipulation commands:
     clear                clear the whole stack
     shift                remove the last element of the stack
     reverse              reverse the stack elements
     swap                 exchange the last two stack elements
     dup                  duplicate last stack item
-    history              display calculation history
+    undo                 undo last operation
+
+Other commands:
     help|?               show this message
+    manual               show manual
     quit|exit|c-d|c-c    exit program