revert exists(), unused

* re-organized command structure
* added 'dup' command

calc.go

@@ -20,8 +20,8 @@ package main
 import (
 	"errors"
 	"fmt"
-	"os"
 	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -48,24 +48,17 @@ type Calc struct {
 	Funcalls      Funcalls
 	BatchFuncalls Funcalls
 
+	// different kinds of commands, displays nicer in help output
+	StackCommands    Commands
+	SettingsCommands Commands
+	ShowCommands     Commands
+	Commands         Commands
+
 	Vars map[string]float64
 }
 
 // help for lua functions will be added dynamically
-const Help string = `Available commands:
+const Help string = `
-batch                toggle batch mode
-debug                toggle debug output
-show                 show the last 5 items of the stack
-dump                 display the stack contents
-clear                clear the whole stack
-shift                remove the last element of the stack
-reverse              reverse the stack elements
-swap                 exchange the last two elements
-vars                 show list of variables
-history              display calculation history
-help|?               show this message
-quit|exit|c-d|c-c    exit program
-
 Operators:
 basic operators: + - x * / ^  (* is an alias of x)
 
@@ -94,7 +87,7 @@ Register variables:
 // commands, constants and operators,  defined here to feed completion
 // and our mode switch in Eval() dynamically
 const (
-	Commands  string = `dump reverse debug undebug clear batch shift undo help history manual exit quit swap show vars`
+	//Commands  string = `dump reverse clear shift undo help history manual exit quit swap debug undebug nodebug batch nobatch showstack noshowstack vars`
 	Constants string = `Pi Phi Sqrt2 SqrtE SqrtPi SqrtPhi Ln2 Log2E Ln10 Log10E`
 )
 
@@ -107,7 +100,6 @@ func GetCompleteCustomFunctions() func(string) []string {
 			completions = append(completions, luafunc)
 		}
 
-		completions = append(completions, strings.Split(Commands, " ")...)
 		completions = append(completions, strings.Split(Constants, " ")...)
 
 		return completions
@@ -126,6 +118,22 @@ func (c *Calc) GetCompleteCustomFuncalls() func(string) []string {
 			completions = append(completions, function)
 		}
 
+		for command := range c.SettingsCommands {
+			completions = append(completions, command)
+		}
+
+		for command := range c.ShowCommands {
+			completions = append(completions, command)
+		}
+
+		for command := range c.StackCommands {
+			completions = append(completions, command)
+		}
+
+		for command := range c.Commands {
+			completions = append(completions, command)
+		}
+
 		return completions
 	}
 
@@ -151,6 +159,8 @@ func NewCalc() *Calc {
 	// pre-calculate mode switching arrays
 	c.Constants = strings.Split(Constants, " ")
 
+	c.SetCommands()
+
 	return &c
 }
 
@@ -274,65 +284,32 @@ func (c *Calc) Eval(line string) {
 				continue
 			}
 
-			// management commands
+			// internal commands
+			if _, ok := c.Commands[item]; ok {
+				c.Commands[item].Func(c)
+				continue
+			}
+
+			if _, ok := c.ShowCommands[item]; ok {
+				c.ShowCommands[item].Func(c)
+				continue
+			}
+
+			if _, ok := c.StackCommands[item]; ok {
+				c.StackCommands[item].Func(c)
+				continue
+			}
+
+			if _, ok := c.SettingsCommands[item]; ok {
+				c.SettingsCommands[item].Func(c)
+				continue
+			}
+
 			switch item {
 			case "?":
 				fallthrough
 			case "help":
-				fmt.Println(Help)
+				c.PrintHelp()
-				if len(LuaFuncs) > 0 {
-					fmt.Println("Lua functions:")
-					for name, function := range LuaFuncs {
-						fmt.Printf("%-20s %s\n", name, function.help)
-					}
-				}
-			case "dump":
-				c.stack.Dump()
-			case "debug":
-				c.ToggleDebug()
-			case "undebug":
-				c.debug = false
-			case "batch":
-				c.ToggleBatch()
-			case "clear":
-				c.stack.Backup()
-				c.stack.Clear()
-			case "shift":
-				c.stack.Backup()
-				c.stack.Shift()
-			case "reverse":
-				c.stack.Backup()
-				c.stack.Reverse()
-			case "swap":
-				if c.stack.Len() < 2 {
-					fmt.Println("stack too small, can't swap")
-				} else {
-					c.stack.Backup()
-					c.stack.Swap()
-				}
-			case "undo":
-				c.stack.Restore()
-			case "history":
-				for _, entry := range c.history {
-					fmt.Println(entry)
-				}
-			case "show":
-				c.ToggleShow()
-			case "exit":
-				fallthrough
-			case "quit":
-				os.Exit(0)
-			case "manual":
-				man()
-			case "vars":
-				if len(c.Vars) > 0 {
-					fmt.Printf("%-20s     %s\n", "VARIABLE", "VALUE")
-					for k, v := range c.Vars {
-						fmt.Printf("%-20s  -> %.2f\n", k, v)
-					}
-				} else {
-					fmt.Println("no vars registered")
-				}
 
 			default:
 				fmt.Println("unknown command or operator!")
@@ -519,3 +496,51 @@ func (c *Calc) GetVar(name string) {
 		fmt.Println("variable doesn't exist")
 	}
 }
+
+func sortcommands(hash Commands) []string {
+	keys := make([]string, 0, len(hash))
+
+	for key := range hash {
+		keys = append(keys, key)
+	}
+
+	sort.Strings(keys)
+
+	return keys
+}
+
+func (c *Calc) PrintHelp() {
+	fmt.Println("Available configuration commands:")
+	for _, name := range sortcommands(c.SettingsCommands) {
+		fmt.Printf("%-20s %s\n", name, c.SettingsCommands[name].Help)
+	}
+	fmt.Println()
+
+	fmt.Println("Available show commands:")
+	for _, name := range sortcommands(c.ShowCommands) {
+		fmt.Printf("%-20s %s\n", name, c.ShowCommands[name].Help)
+	}
+	fmt.Println()
+
+	fmt.Println("Available stack manipulation commands:")
+	for _, name := range sortcommands(c.StackCommands) {
+		fmt.Printf("%-20s %s\n", name, c.StackCommands[name].Help)
+	}
+	fmt.Println()
+
+	fmt.Println("Other commands:")
+	for _, name := range sortcommands(c.Commands) {
+		fmt.Printf("%-20s %s\n", name, c.Commands[name].Help)
+	}
+	fmt.Println()
+
+	fmt.Println(Help)
+
+	// append lua functions, if any
+	if len(LuaFuncs) > 0 {
+		fmt.Println("Lua functions:")
+		for name, function := range LuaFuncs {
+			fmt.Printf("%-20s %s\n", name, function.help)
+		}
+	}
+}

command.go

@@ -0,0 +1,201 @@
+/*
+Copyright © 2023 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+type CommandFunction func(*Calc)
+
+type Command struct {
+	Help string
+	Func CommandFunction
+}
+
+type Commands map[string]*Command
+
+func NewCommand(help string, function CommandFunction) *Command {
+	return &Command{
+		Help: help,
+		Func: function,
+	}
+}
+
+// define all management (that is: non calculation) commands
+func (c *Calc) SetCommands() {
+	c.SettingsCommands = Commands{
+		// Toggles
+		"debug": NewCommand(
+			"toggle debugging",
+			func(c *Calc) {
+				c.ToggleDebug()
+			},
+		),
+
+		"nodebug": NewCommand(
+			"disable debugging",
+			func(c *Calc) {
+				c.debug = false
+				c.stack.debug = false
+			},
+		),
+
+		"batch": NewCommand(
+			"toggle batch mode",
+			func(c *Calc) {
+				c.ToggleBatch()
+			},
+		),
+
+		"nobatch": NewCommand(
+			"disable batch mode",
+			func(c *Calc) {
+				c.batch = false
+			},
+		),
+
+		"showstack": NewCommand(
+			"toggle show last 5 items of the stack",
+			func(c *Calc) {
+				c.ToggleShow()
+			},
+		),
+
+		"noshowstack": NewCommand(
+			"disable display of the stack",
+			func(c *Calc) {
+				c.showstack = false
+			},
+		),
+	}
+
+	c.ShowCommands = Commands{
+		// Display commands
+		"dump": NewCommand(
+			"display the stack contents",
+			func(c *Calc) {
+				c.stack.Dump()
+			},
+		),
+
+		"history": NewCommand(
+			"display calculation history",
+			func(c *Calc) {
+				for _, entry := range c.history {
+					fmt.Println(entry)
+				}
+			},
+		),
+
+		"vars": NewCommand(
+			"show list of variables",
+			func(c *Calc) {
+				if len(c.Vars) > 0 {
+					fmt.Printf("%-20s     %s\n", "VARIABLE", "VALUE")
+					for k, v := range c.Vars {
+						fmt.Printf("%-20s  -> %.2f\n", k, v)
+					}
+				} else {
+					fmt.Println("no vars registered")
+				}
+			},
+		),
+	}
+
+	c.StackCommands = Commands{
+		"clear": NewCommand(
+			"clear the whole stack",
+			func(c *Calc) {
+				c.stack.Backup()
+				c.stack.Clear()
+			},
+		),
+
+		"shift": NewCommand(
+			"remove the last element of the stack",
+			func(c *Calc) {
+				c.stack.Backup()
+				c.stack.Shift()
+			},
+		),
+
+		"reverse": NewCommand(
+			"reverse the stack elements",
+			func(c *Calc) {
+				c.stack.Backup()
+				c.stack.Reverse()
+			},
+		),
+
+		"swap": NewCommand(
+			"exchange the last two elements",
+			func(c *Calc) {
+				if c.stack.Len() < 2 {
+					fmt.Println("stack too small, can't swap")
+				} else {
+					c.stack.Backup()
+					c.stack.Swap()
+				}
+			},
+		),
+
+		"undo": NewCommand(
+			"undo last operation",
+			func(c *Calc) {
+				c.stack.Restore()
+			},
+		),
+
+		"dup": NewCommand(
+			"duplicate last stack item",
+			func(c *Calc) {
+				item := c.stack.Last()
+				if len(item) == 1 {
+					c.stack.Backup()
+					c.stack.Push(item[0])
+				} else {
+					fmt.Println("stack empty")
+				}
+			},
+		),
+	}
+
+	// general commands
+	c.Commands = Commands{
+		"exit": NewCommand(
+			"exit program",
+			func(c *Calc) {
+				os.Exit(0)
+			},
+		),
+
+		"manual": NewCommand(
+			"show manual",
+			func(c *Calc) {
+				man()
+			},
+		),
+	}
+
+	// aliases
+	c.Commands["quit"] = c.Commands["exit"]
+	c.SettingsCommands["undebug"] = c.SettingsCommands["nodebug"]
+	c.SettingsCommands["show"] = c.SettingsCommands["showstack"]
+}

main.go

@@ -30,7 +30,7 @@ import (
 	lua "github.com/yuin/gopher-lua"
 )
 
-const VERSION string = "2.0.7"
+const VERSION string = "2.0.9"
 
 const Usage string = `This is rpn, a reverse polish notation calculator cli.
 

rpn.go

@@ -152,14 +152,15 @@ DESCRIPTION
 
     Commands:
 
-        batch                toggle batch mode
+        [no]batch            toggle batch mode (nobatch turns it off)
-        debug                toggle debug output
+        [no]debug            toggle debug output (nodebug turns it off)
+        [no]showstack        show the last 5 items of the stack (noshowtack turns it off)
         dump                 display the stack contents
         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
-        show                 show the last 5 items of the stack
+        dup                  duplicate last stack item
         history              display calculation history
         help|?               show this message
         quit|exit|c-d|c-c    exit program

rpn.pod

@@ -159,14 +159,15 @@ Math functions:
 
 Commands:
 
-    batch                toggle batch mode
+    [no]batch            toggle batch mode (nobatch turns it off)
-    debug                toggle debug output
+    [no]debug            toggle debug output (nodebug turns it off)
+    [no]showstack        show the last 5 items of the stack (noshowtack turns it off)
     dump                 display the stack contents
     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
-    show                 show the last 5 items of the stack
+    dup                  duplicate last stack item
     history              display calculation history
     help|?               show this message
     quit|exit|c-d|c-c    exit program