fix printing of fractionals (not scientific anymore), added -p flag

* reorganized Eval() to return errors and call EvalItem() on each item
* fix negative shift amount error, found with fuzzy testing :)
* added fuzzy testing

Makefile

@@ -51,10 +51,13 @@ install: buildlocal
 	install -o $(UID) -g $(GID) -m 444 $(tool).1 $(PREFIX)/man/man1/
 
 clean:
-	rm -rf $(tool) coverage.out
+	rm -rf $(tool) coverage.out testdata
 
-test:
-	go test -v ./...
+test: clean
+	go test ./... $(ARGS)
+
+testfuzzy: clean
+	go test -fuzz ./... $(ARGS)
 
 singletest:
 	@echo "Call like this: make singletest TEST=TestPrepareColumns ARGS=-v"

calc.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2023 Thomas von Dein
+Copyright © 2023-2024 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
@@ -20,6 +20,7 @@ package main
 import (
 	"errors"
 	"fmt"
+	"math"
 	"regexp"
 	"sort"
 	"strconv"
@@ -35,6 +36,8 @@ type Calc struct {
 	showstack    bool
 	intermediate bool
 	notdone      bool // set to true as long as there are items left in the eval loop
+	precision    int
+
 	stack        *Stack
 	history      []string
 	completer    readline.AutoCompleter
@@ -91,6 +94,7 @@ Register variables:
 const (
 	//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`
+	Precision int    = 2
 )
 
 // That way we can add custom functions to completion
@@ -150,7 +154,7 @@ func (c *Calc) GetCompleteCustomFuncalls() func(string) []string {
 }
 
 func NewCalc() *Calc {
-	c := Calc{stack: NewStack(), debug: false}
+	c := Calc{stack: NewStack(), debug: false, precision: Precision}
 
 	c.Funcalls = DefineFunctions()
 	c.BatchFuncalls = DefineBatchFunctions()
@@ -222,12 +226,12 @@ func (c *Calc) Prompt() string {
 }
 
 // the actual work horse, evaluate a line of calc command[s]
-func (c *Calc) Eval(line string) {
+func (c *Calc) Eval(line string) error {
 	// remove surrounding whitespace and comments, if any
 	line = strings.TrimSpace(c.Comment.ReplaceAllString(line, ""))
 
 	if line == "" {
-		return
+		return nil
 	}
 
 	items := c.Space.Split(line, -1)
@@ -239,98 +243,8 @@ func (c *Calc) Eval(line string) {
 			c.notdone = false
 		}
 
-		num, err := strconv.ParseFloat(item, 64)
-
-		if err == nil {
-			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()
-				c.stack.Push(const2num(item))
-				continue
-			}
-
-			if exists(c.Funcalls, item) {
-				if err := c.DoFuncall(item); err != nil {
-					fmt.Println(err)
-				} else {
-					c.Result()
-				}
-				continue
-			}
-
-			if exists(c.BatchFuncalls, item) {
-				if !c.batch {
-					fmt.Println("only supported in batch mode")
-					continue
-				}
-
-				if err := c.DoFuncall(item); err != nil {
-					fmt.Println(err)
-				} else {
-					c.Result()
-				}
-				continue
-			}
-
-			if contains(c.LuaFunctions, item) {
-				// user provided custom lua functions
-				c.EvalLuaFunction(item)
-				continue
-			}
-
-			regmatches := c.Register.FindStringSubmatch(item)
-			if len(regmatches) == 3 {
-				switch regmatches[1] {
-				case ">":
-					c.PutVar(regmatches[2])
-				case "<":
-					c.GetVar(regmatches[2])
-				}
-				continue
-			}
-
-			// internal commands
-			if exists(c.Commands, item) {
-				c.Commands[item].Func(c)
-				continue
-			}
-
-			if exists(c.ShowCommands, item) {
-				c.ShowCommands[item].Func(c)
-				continue
-			}
-
-			if exists(c.StackCommands, item) {
-				c.StackCommands[item].Func(c)
-				continue
-			}
-
-			if exists(c.SettingsCommands, item) {
-				c.SettingsCommands[item].Func(c)
-				continue
-			}
-
-			switch item {
-			case "?":
-				fallthrough
-			case "help":
-				c.PrintHelp()
-
-			default:
-				fmt.Println("unknown command or operator!")
-			}
+		if err := c.EvalItem(item); err != nil {
+			return err
 		}
 	}
 
@@ -343,6 +257,106 @@ func (c *Calc) Eval(line string) {
 		last := c.stack.Last(5)
 		fmt.Printf("stack: %s%s\n", dots, list2str(last))
 	}
+
+	return nil
+}
+
+func (c *Calc) EvalItem(item string) error {
+	num, err := strconv.ParseFloat(item, 64)
+
+	if err == nil {
+		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))
+			return nil
+		}
+
+		if contains(c.Constants, item) {
+			// put the constant onto the stack
+			c.stack.Backup()
+			c.stack.Push(const2num(item))
+			return nil
+		}
+
+		if exists(c.Funcalls, item) {
+			if err := c.DoFuncall(item); err != nil {
+				return Error(err.Error())
+			} else {
+				c.Result()
+			}
+			return nil
+		}
+
+		if exists(c.BatchFuncalls, item) {
+			if !c.batch {
+				return Error("only supported in batch mode")
+			}
+
+			if err := c.DoFuncall(item); err != nil {
+				return Error(err.Error())
+			} else {
+				c.Result()
+			}
+			return nil
+		}
+
+		if contains(c.LuaFunctions, item) {
+			// user provided custom lua functions
+			c.EvalLuaFunction(item)
+			return nil
+		}
+
+		regmatches := c.Register.FindStringSubmatch(item)
+		if len(regmatches) == 3 {
+			switch regmatches[1] {
+			case ">":
+				c.PutVar(regmatches[2])
+			case "<":
+				c.GetVar(regmatches[2])
+			}
+			return nil
+		}
+
+		// internal commands
+		// FIXME: propagate errors
+		if exists(c.Commands, item) {
+			c.Commands[item].Func(c)
+			return nil
+		}
+
+		if exists(c.ShowCommands, item) {
+			c.ShowCommands[item].Func(c)
+			return nil
+		}
+
+		if exists(c.StackCommands, item) {
+			c.StackCommands[item].Func(c)
+			return nil
+		}
+
+		if exists(c.SettingsCommands, item) {
+			c.SettingsCommands[item].Func(c)
+			return nil
+		}
+
+		switch item {
+		case "?":
+			fallthrough
+		case "help":
+			c.PrintHelp()
+
+		default:
+			return Error("unknown command or operator")
+		}
+	}
+
+	return nil
 }
 
 // Execute a math function, check if it is defined just in case
@@ -355,7 +369,7 @@ func (c *Calc) DoFuncall(funcname string) error {
 	}
 
 	if function == nil {
-		panic("function not defined but in completion list")
+		return Error("function not defined but in completion list")
 	}
 
 	var args Numbers
@@ -428,7 +442,16 @@ func (c *Calc) Result() float64 {
 			fmt.Print("= ")
 		}
 
-		fmt.Println(c.stack.Last()[0])
+		result := c.stack.Last()[0]
+		truncated := math.Trunc(result)
+		precision := c.precision
+
+		if result == truncated {
+			precision = 0
+		}
+
+		format := fmt.Sprintf("%%.%df\n", precision)
+		fmt.Printf(format, result)
 	}
 
 	return c.stack.Last()[0]

calc_test.go

@@ -19,6 +19,8 @@ package main
 
 import (
 	"fmt"
+	"strconv"
+	"strings"
 	"testing"
 
 	lua "github.com/yuin/gopher-lua"
@@ -75,7 +77,9 @@ func TestCommentsAndWhitespace(t *testing.T) {
 
 		t.Run(testname, func(t *testing.T) {
 			for _, line := range tt.cmd {
-				calc.Eval(line)
+				if err := calc.Eval(line); err != nil {
+					t.Errorf(err.Error())
+				}
 			}
 			got := calc.stack.Last()
 
@@ -288,7 +292,9 @@ func TestCalc(t *testing.T) {
 
 		t.Run(testname, func(t *testing.T) {
 			calc.batch = tt.batch
-			calc.Eval(tt.cmd)
+			if err := calc.Eval(tt.cmd); err != nil {
+				t.Errorf(err.Error())
+			}
 			got := calc.Result()
 			calc.stack.Clear()
 			if got != tt.exp {
@@ -350,3 +356,60 @@ func TestCalcLua(t *testing.T) {
 		})
 	}
 }
+
+func FuzzEval(f *testing.F) {
+	legal := []string{
+		"dump",
+		"showstack",
+		"help",
+		"Pi 31 *",
+		"SqrtE Pi /",
+		"55.5 yards-to-meters",
+		"2 4 +",
+		"7 8 batch sum",
+		"7 8 %-",
+		"7 8 clear",
+		"7 8 /",
+		"b",
+		"#444",
+		"<X",
+	}
+
+	for _, item := range legal {
+		f.Add(item)
+	}
+
+	calc := NewCalc()
+	var i int
+
+	f.Fuzz(func(t *testing.T, line string) {
+		t.Logf("Stack:\n%v\n", calc.stack.All())
+		if err := calc.EvalItem(line); err == nil {
+			t.Logf("given: <%s>", line)
+			// not corpus and empty?
+			if !contains(legal, line) && len(line) > 0 {
+				item := strings.TrimSpace(calc.Comment.ReplaceAllString(line, ""))
+				_, hexerr := fmt.Sscanf(item, "0x%x", &i)
+				// no comment?
+				if len(item) > 0 {
+					// no known command or function?
+					if _, err := strconv.ParseFloat(item, 64); err != nil {
+						if !contains(calc.Constants, item) &&
+							!exists(calc.Funcalls, item) &&
+							!exists(calc.BatchFuncalls, item) &&
+							!contains(calc.LuaFunctions, item) &&
+							!exists(calc.Commands, item) &&
+							!exists(calc.ShowCommands, item) &&
+							!exists(calc.SettingsCommands, item) &&
+							!exists(calc.StackCommands, item) &&
+							!calc.Register.MatchString(item) &&
+							item != "?" && item != "help" &&
+							hexerr != nil {
+							t.Errorf("Fuzzy input accepted: <%s>", line)
+						}
+					}
+				}
+			}
+		}
+	})
+}

funcs.go

@@ -457,12 +457,20 @@ func DefineFunctions() Funcalls {
 
 		"<": NewFuncall(
 			func(arg Numbers) R {
+				// Shift by negative number provibited, so check it.
+				// Note that we check agains uint64 overflow as well here
+				if arg[1] < 0 || uint64(arg[1]) > math.MaxInt64 {
+					return NewR(0, errors.New("negative shift amount"))
+				}
 				return NewR(float64(int(arg[0])<<int(arg[1])), nil)
 			},
 			2),
 
 		">": NewFuncall(
 			func(arg Numbers) R {
+				if arg[1] < 0 || uint64(arg[1]) > math.MaxInt64 {
+					return NewR(0, errors.New("negative shift amount"))
+				}
 				return NewR(float64(int(arg[0])>>int(arg[1])), nil)
 			},
 			2),

main.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2023 Thomas von Dein
+Copyright © 2023-2024 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
@@ -30,26 +30,27 @@ import (
 	lua "github.com/yuin/gopher-lua"
 )
 
-const VERSION string = "2.0.12"
+const VERSION string = "2.1.0"
 
 const Usage string = `This is rpn, a reverse polish notation calculator cli.
 
 Usage: rpn [-bdvh] [<operator>]
 
 Options:
-  -b, --batchmode     enable batch mode
-  -d, --debug         enable debug mode
-  -s, --stack         show last 5 items of the stack (off by default)
-  -i  --intermediate  print intermediate results
-  -m, --manual        show manual
-  -c, --config <file> load <file> containing LUA code
-  -v, --version       show version
-  -h, --help          show help
+  -b, --batchmode       enable batch mode
+  -d, --debug           enable debug mode
+  -s, --stack           show last 5 items of the stack (off by default)
+  -i  --intermediate    print intermediate results
+  -m, --manual          show manual
+  -c, --config <file>   load <file> containing LUA code
+  -p, --precision <int> floating point number precision (default 2)
+  -v, --version         show version
+  -h, --help            show help
 
 When <operator>  is given, batch  mode ist automatically  enabled. Use
 this only when working with stdin. E.g.: echo "2 3 4 5" | rpn +
 
-Copyright (c) 2023 T.v.Dein`
+Copyright (c) 2023-2024 T.v.Dein`
 
 func main() {
 	os.Exit(Main())
@@ -74,6 +75,7 @@ func Main() int {
 	flag.BoolVarP(&showmanual, "manual", "m", false, "show manual")
 	flag.StringVarP(&configfile, "config", "c",
 		os.Getenv("HOME")+"/.rpn.lua", "config file (lua format)")
+	flag.IntVarP(&calc.precision, "precision", "p", Precision, "floating point precision")
 
 	flag.Parse()
 
@@ -119,7 +121,11 @@ func Main() int {
 		// commandline calc operation, no readline etc needed
 		// called like rpn 2 2 +
 		calc.stdin = true
-		calc.Eval(strings.Join(flag.Args(), " "))
+		if err := calc.Eval(strings.Join(flag.Args(), " ")); err != nil {
+			fmt.Println(err)
+			return 1
+		}
+
 		return 0
 	}
 
@@ -153,7 +159,10 @@ func Main() int {
 			break
 		}
 
-		calc.Eval(line)
+		err = calc.Eval(line)
+		if err != nil {
+			fmt.Println(err)
+		}
 		rl.SetPrompt(calc.Prompt())
 	}
 
@@ -162,7 +171,10 @@ func Main() int {
 		// echo 1 2 3 4 | rpn +
 		// batch mode enabled automatically
 		calc.batch = true
-		calc.Eval(flag.Args()[0])
+		if err = calc.Eval(flag.Args()[0]); err != nil {
+			fmt.Println(err)
+			return 1
+		}
 	}
 
 	return 0

rpn.go

@@ -8,13 +8,15 @@ SYNOPSIS
         Usage: rpn [-bdvh] [<operator>]
     
         Options:
-          -b, --batchmode     enable batch mode
-          -d, --debug         enable debug mode
-          -s, --stack         show last 5 items of the stack (off by default)
-          -i  --intermediate  print intermediate results
-          -m, --manual        show manual
-          -v, --version       show version
-          -h, --help          show help
+          -b, --batchmode       enable batch mode
+          -d, --debug           enable debug mode
+          -s, --stack           show last 5 items of the stack (off by default)
+          -i  --intermediate    print intermediate results
+          -m, --manual          show manual
+          -c, --config <file>   load <file> containing LUA code
+          -p, --precision <int> floating point number precision (default 2)
+          -v, --version         show version
+          -h, --help            show help
     
         When <operator>  is given, batch  mode ist automatically  enabled. Use
         this only when working with stdin. E.g.: echo "2 3 4 5" | rpn +
@@ -309,6 +311,15 @@ EXTENDING RPN USING LUA
     So you can't open files, execute other programs or open a connection to
     the outside!
 
+CONFIGURATION
+    rpn can be configured via command line flags (see usage above). Most of
+    the flags are also available as interactive commands, such as "--batch"
+    has the same effect as the batch command.
+
+    The floating point number precision option "-p, --precision" however is
+    not available as interactive command, it MUST be configured on the
+    command line, if needed. The default precision is 2.
+
 GETTING HELP
     In interactive mode you can enter the help command (or ?) to get a short
     help along with a list of all supported operators and functions.
@@ -328,7 +339,7 @@ LICENSE
     This software is licensed under the GNU GENERAL PUBLIC LICENSE version
     3.
 
-    Copyright (c) 2023 by Thomas von Dein
+    Copyright (c) 2023-2024 by Thomas von Dein
 
     This software uses the following GO modules:
 

rpn.pod

@@ -7,13 +7,15 @@ rpn - Programmable command-line calculator using reverse polish notation
     Usage: rpn [-bdvh] [<operator>]
     
     Options:
-      -b, --batchmode     enable batch mode
-      -d, --debug         enable debug mode
-      -s, --stack         show last 5 items of the stack (off by default)
-      -i  --intermediate  print intermediate results
-      -m, --manual        show manual
-      -v, --version       show version
-      -h, --help          show help
+      -b, --batchmode       enable batch mode
+      -d, --debug           enable debug mode
+      -s, --stack           show last 5 items of the stack (off by default)
+      -i  --intermediate    print intermediate results
+      -m, --manual          show manual
+      -c, --config <file>   load <file> containing LUA code
+      -p, --precision <int> floating point number precision (default 2)
+      -v, --version         show version
+      -h, --help            show help
     
     When <operator>  is given, batch  mode ist automatically  enabled. Use
     this only when working with stdin. E.g.: echo "2 3 4 5" | rpn +
@@ -342,6 +344,16 @@ B<Please note, that io, networking and system stuff is not allowed
 though. So you can't open files, execute other programs or open a
 connection to the outside!>
 
+=head1 CONFIGURATION
+
+B<rpn> can be configured via command line flags (see usage
+above). Most of the flags are also available as interactive commands,
+such as C<--batch> has the same effect as the B<batch> command.
+
+The floating point number  precision option C<-p, --precision> however
+is not available as interactive command,  it MUST be configured on the
+command line, if needed. The default precision is 2.
+
 =head1 GETTING HELP
 
 In interactive mode you can enter the B<help> command (or B<?>) to get
@@ -364,7 +376,7 @@ L<https://github.com/TLINDEN/rpnc/issues>.
 
 This software is licensed under the GNU GENERAL PUBLIC LICENSE version 3.
 
-Copyright (c) 2023 by Thomas von Dein
+Copyright (c) 2023-2024 by Thomas von Dein
 
 This software uses the following GO modules:
 

t/cmdline-invalidcommand.txtar

@@ -1,2 +1,2 @@
-exec testrpn 1 2 dumb
+! exec testrpn 1 2 dumb
 stdout 'unknown command or operator'

t/cmdline-precision.txtar

@@ -0,0 +1,2 @@
+exec testrpn -p 4 2 3 /
+stdout '0.6667\n'

t/cmdline-short-stack.txtar

@@ -1,2 +1,2 @@
-exec testrpn 4 +
+! exec testrpn 4 +
 stdout 'stack doesn''t provide enough arguments'

t/cmdlinecalc-divzero.txtar

@@ -1,2 +1,2 @@
-exec testrpn 100 50 50 - /
-stdout 'division by null\n'
+! exec testrpn 100 50 50 - /
+stdout 'division by null'

util.go

@@ -71,3 +71,7 @@ func const2num(name string) float64 {
 func list2str(list Numbers) string {
 	return strings.Trim(strings.Join(strings.Fields(fmt.Sprint(list)), " "), "[]")
 }
+
+func Error(m string) error {
+	return fmt.Errorf("Error: %s!", m)
+}