Initial integration with fortio.org/terminal (#120)

* initial integration with fortio.org/terminal

* eof/^c aren't errors, for now use compact form to add to history

* add history, !n, and help commands to interactive mode

* add info about history interactive repl feature and max-history flag

* terminal with fix for -logger-no-color

* cleanup eof code, no setprompt needed, done by terminal/ now

* use os.UserConfigDir for now but I don't like it

* Switch back to home dir but add GROL_HISTORY_FILE env option, also use home dir as a virtual '~/' that gets replaced by actual if unchanged from default, so pasting help doesn't leak the home dir

* use terminal 0.7.0, term.LoggerSetup is automatic

* Use the constant from the package as default

* Fix up the go.mod

Author: ldemailly

README.md

@@ -65,6 +65,9 @@ $ info.keywords
 == Eval  ==> ["else","error","false","first","func","if","len","log","macro","print","println","quote","rest","return","true","unquote"]
 ```
 
+There is also in interactive repl mode: `history`, `!23` to repeat the 23rd statement for instance and `help`.
+And full edit and history navigation with arrow keys etc...
+
 ## Language features
 
 Functional int, float, string and boolean expressions
@@ -167,7 +170,7 @@ See [Open Issues](https://grol.io/grol/issues) for what's left to do
 ### CLI Usage
 
 ```
-grol 0.29.0 usage:
+grol 0.38.0 usage:
 	grol [flags] *.gr files to interpret or `-` for stdin without prompt
   or no arguments for stdin repl...
 or 1 of the special arguments
@@ -181,9 +184,15 @@ flags:
     	show eval results (default true)
   -format
     	don't execute, just parse and re format the input
+  -history string
+    	history file to use (default "~/.grol_history")
+  -max-history size
+    	max history size, use 0 to disable. (default 99)
   -parse
     	show parse tree
   -shared-state
     	All files share same interpreter state (default is new state for each)
 ```
 (excluding logger control, see `gorepl help` for all the flags, of note `-logger-no-color` will turn off colors for gorepl too, for development there are also `-profile*` options for pprof, when building without `no_pprof`)
+
+If you don't want to pass a flag and want to permanently change the `grol` history file location from your HOME directory, set GROL_HISTORY_FILE in the environment.

go.mod

@@ -6,15 +6,17 @@ require (
 	fortio.org/cli v1.8.0
 	fortio.org/log v1.16.0
 	fortio.org/sets v1.2.0
+	fortio.org/struct2env v0.4.1
+	fortio.org/terminal v0.7.2
 	fortio.org/testscript v0.3.1 // only for tests
 	fortio.org/version v1.0.4
 )
 
 require (
-	fortio.org/struct2env v0.4.1 // indirect
+	fortio.org/term v0.23.0-fortio-6 // indirect
 	github.com/kortschak/goroutine v1.1.2 // indirect
-	golang.org/x/crypto/x509roots/fallback v0.0.0-20240626151235-a6a393ffd658 // indirect
-	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 // indirect
-	golang.org/x/sys v0.22.0 // indirect
-	golang.org/x/tools v0.23.0 // indirect
+	golang.org/x/crypto/x509roots/fallback v0.0.0-20240806160748-b2d3a6a4b4d3 // indirect
+	golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa // indirect
+	golang.org/x/sys v0.24.0 // indirect
+	golang.org/x/tools v0.24.0 // indirect
 )

go.sum

@@ -8,17 +8,21 @@ fortio.org/sets v1.2.0 h1:FBfC7R2xrOJtkcioUbY6WqEzdujuBoZRbSdp1fYF4Kk=
 fortio.org/sets v1.2.0/go.mod h1:J2BwIxNOLWsSU7IMZUg541kh3Au4JEKHrghVwXs68tE=
 fortio.org/struct2env v0.4.1 h1:rJludAMO5eBvpWplWEQNqoVDFZr4RWMQX7RUapgZyc0=
 fortio.org/struct2env v0.4.1/go.mod h1:lENUe70UwA1zDUCX+8AsO663QCFqYaprk5lnPhjD410=
+fortio.org/term v0.23.0-fortio-6 h1:pKrUX0tKOxyEhkhLV50oJYucTVx94rzFrXc24lIuLvk=
+fortio.org/term v0.23.0-fortio-6/go.mod h1:7buBfn81wEJUGWiVjFNiUE/vxWs5FdM9c7PyZpZRS30=
+fortio.org/terminal v0.7.2 h1:Bfpw6ORqrpaTVtlP0NxSS2VyfESR17DvT9qqz75ixJU=
+fortio.org/terminal v0.7.2/go.mod h1:Z/dydQSo8hCwiUGOt2pJiR8OsNAFn6pTt3pbHDsdtSM=
 fortio.org/testscript v0.3.1 h1:MmRO64AsmzaU1KlYMzAbotJIMKRGxD1XXssJnBRiMGQ=
 fortio.org/testscript v0.3.1/go.mod h1:7OJ+U4avooRNqc7p/VHKJadYgj9fA6+N0SbGU8FVWGs=
 fortio.org/version v1.0.4 h1:FWUMpJ+hVTNc4RhvvOJzb0xesrlRmG/a+D6bjbQ4+5U=
 fortio.org/version v1.0.4/go.mod h1:2JQp9Ax+tm6QKiGuzR5nJY63kFeANcgrZ0osoQFDVm0=
 github.com/kortschak/goroutine v1.1.2 h1:lhllcCuERxMIK5cYr8yohZZScL1na+JM5JYPRclWjck=
 github.com/kortschak/goroutine v1.1.2/go.mod h1:zKpXs1FWN/6mXasDQzfl7g0LrGFIOiA6cLs9eXKyaMY=
-golang.org/x/crypto/x509roots/fallback v0.0.0-20240626151235-a6a393ffd658 h1:i7K6wQLN/0oxF7FT3tKkfMCstxoT4VGG36YIB9ZKLzI=
-golang.org/x/crypto/x509roots/fallback v0.0.0-20240626151235-a6a393ffd658/go.mod h1:kNa9WdvYnzFwC79zRpLRMJbdEFlhyM5RPFBBZp/wWH8=
-golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 h1:2dVuKD2vS7b0QIHQbpyTISPd0LeHDbnYEryqj5Q1ug8=
-golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56/go.mod h1:M4RDyNAINzryxdtnbRXRL/OHtkFuWGRjvuhBJpk2IlY=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/tools v0.23.0 h1:SGsXPZ+2l4JsgaCKkx+FQ9YZ5XEtA1GZYuoDjenLjvg=
-golang.org/x/tools v0.23.0/go.mod h1:pnu6ufv6vQkll6szChhK3C3L/ruaIv5eBeztNG8wtsI=
+golang.org/x/crypto/x509roots/fallback v0.0.0-20240806160748-b2d3a6a4b4d3 h1:oWb21rU9Q9XrRwXLB7jHc1rbp6EiiimZZv5MLxpu4T0=
+golang.org/x/crypto/x509roots/fallback v0.0.0-20240806160748-b2d3a6a4b4d3/go.mod h1:kNa9WdvYnzFwC79zRpLRMJbdEFlhyM5RPFBBZp/wWH8=
+golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa h1:ELnwvuAXPNtPk1TJRuGkI9fDTwym6AYBu0qzT8AcHdI=
+golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa/go.mod h1:akd2r19cwCdwSwWeIdzYQGa/EZZyqcOdwWiwj5L5eKQ=
+golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
+golang.org/x/sys v0.24.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/tools v0.24.0 h1:J1shsA93PJUEVaUSaay7UXAyE8aimq3GW0pjlolpa24=
+golang.org/x/tools v0.24.0/go.mod h1:YhNqVBIfWHdzvTLs0d8LCuMhkKUgSUKldakyV7W/WDQ=

main.go

@@ -6,9 +6,12 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 
 	"fortio.org/cli"
 	"fortio.org/log"
+	"fortio.org/struct2env"
+	"fortio.org/terminal"
 	"grol.io/grol/eval"
 	"grol.io/grol/extensions" // register extensions
 	"grol.io/grol/object"
@@ -19,6 +22,19 @@ func main() {
 	os.Exit(Main())
 }
 
+type Config struct {
+	HistoryFile string
+}
+
+var config = Config{}
+
+func EnvHelp(w io.Writer) {
+	res, _ := struct2env.StructToEnvVars(config)
+	str := struct2env.ToShellWithPrefix("GROL_", res, true)
+	fmt.Fprintln(w, "# Grol environment variables:")
+	fmt.Fprint(w, str)
+}
+
 var hookBefore, hookAfter func() int
 
 func Main() int {
@@ -28,16 +44,38 @@ func Main() int {
 	compact := flag.Bool("compact", false, "When printing code, use no indentation and most compact form")
 	showEval := flag.Bool("eval", true, "show eval results")
 	sharedState := flag.Bool("shared-state", false, "All files share same interpreter state (default is new state for each)")
-
+	const historyDefault = "~/.grol_history" // virtual/token filename, will be replaced by actual home dir if not changed.
+	cli.EnvHelpFuncs = append(cli.EnvHelpFuncs, EnvHelp)
+	defaultHistoryFile := historyDefault
+	errs := struct2env.SetFromEnv("GROL_", &config)
+	if len(errs) > 0 {
+		log.Errf("Error setting config from env: %v", errs)
+	}
+	if config.HistoryFile != "" {
+		defaultHistoryFile = config.HistoryFile
+	}
+	historyFile := flag.String("history", defaultHistoryFile, "history `file` to use")
+	maxHistory := flag.Int("max-history", terminal.DefaultHistoryCapacity, "max history `size`, use 0 to disable.")
 	cli.ArgsHelp = "*.gr files to interpret or `-` for stdin without prompt or no arguments for stdin repl..."
 	cli.MaxArgs = -1
 	cli.Main()
+	histFile := *historyFile
+	if histFile == historyDefault {
+		homeDir, err := os.UserHomeDir()
+		histFile = filepath.Join(homeDir, ".grol_history")
+		if err != nil {
+			log.Warnf("Couldn't get user home dir: %v", err)
+			histFile = ""
+		}
+	}
 	log.Infof("grol %s - welcome!", cli.LongVersion)
 	options := repl.Options{
-		ShowParse:  *showParse,
-		ShowEval:   *showEval,
-		FormatOnly: *format,
-		Compact:    *compact,
+		ShowParse:   *showParse,
+		ShowEval:    *showEval,
+		FormatOnly:  *format,
+		Compact:     *compact,
+		HistoryFile: histFile,
+		MaxHistory:  *maxHistory,
 	}
 	if hookBefore != nil {
 		ret := hookBefore()
@@ -58,8 +96,7 @@ func Main() int {
 		return len(errs)
 	}
 	if len(flag.Args()) == 0 {
-		repl.Interactive(os.Stdin, os.Stdout, options)
-		return 0
+		return repl.Interactive(options)
 	}
 	options.All = true
 	s := eval.NewState()

repl/repl.go

@@ -1,12 +1,16 @@
 package repl
 
 import (
-	"bufio"
+	"errors"
 	"fmt"
 	"io"
+	"regexp"
+	"slices"
+	"strconv"
 	"strings"
 
 	"fortio.org/log"
+	"fortio.org/terminal"
 	"grol.io/grol/ast"
 	"grol.io/grol/eval"
 	"grol.io/grol/lexer"
@@ -33,13 +37,15 @@ func logParserErrors(p *parser.Parser) bool {
 }
 
 type Options struct {
-	ShowParse  bool
-	ShowEval   bool
-	All        bool
-	NoColor    bool // color controlled by log package, unless this is set to true.
-	FormatOnly bool
-	Compact    bool
-	NilAndErr  bool // Show nil and errors in normal output.
+	ShowParse   bool
+	ShowEval    bool
+	All         bool
+	NoColor     bool // color controlled by log package, unless this is set to true.
+	FormatOnly  bool
+	Compact     bool
+	NilAndErr   bool // Show nil and errors in normal output.
+	HistoryFile string
+	MaxHistory  int
 }
 
 func EvalAll(s *eval.State, macroState *object.Environment, in io.Reader, out io.Writer, options Options) []string {
@@ -78,29 +84,73 @@ func EvalString(what string) (res string, errs []string, formatted string) {
 	return
 }
 
-func Interactive(in io.Reader, out io.Writer, options Options) {
+func Interactive(options Options) int {
 	options.NilAndErr = true
 	s := eval.NewState()
 	macroState := object.NewMacroEnvironment()
 
-	scanner := bufio.NewScanner(in)
 	prev := ""
-	prompt := PROMPT
+
+	term, err := terminal.Open()
+	if err != nil {
+		return log.FErrf("Error creating readline: %v", err)
+	}
+	defer term.Close()
+	term.SetPrompt(PROMPT)
+	options.Compact = true // because terminal doesn't (yet) do well will multi-line commands.
+	term.NewHistory(options.MaxHistory)
+	_ = term.SetHistoryFile(options.HistoryFile)
+	// Regular expression for "!nn" to run history command nn.
+	historyRegex := regexp.MustCompile(`^!(\d+)$`)
 	for {
-		fmt.Fprint(out, prompt)
-		scanned := scanner.Scan()
-		if !scanned {
-			return
+		rd, err := term.ReadLine()
+		if errors.Is(err, io.EOF) {
+			log.Infof("Exit requested") // Don't say EOF as ^C comes through as EOF as well.
+			return 0
+		}
+		if err != nil {
+			return log.FErrf("Error reading line: %v", err)
+		}
+		log.Debugf("Read: %q", rd)
+		l := prev + rd
+		if historyRegex.MatchString(l) {
+			h := term.History()
+			slices.Reverse(h)
+			idxStr := l[1:]
+			idx, _ := strconv.Atoi(idxStr)
+			if idx < 1 || idx > len(h) {
+				log.Errf("Invalid history index %d", idx)
+				continue
+			}
+			l = h[idx-1]
+			fmt.Fprintf(term.Out, "Repeating history %d: %s\n", idx, l)
+			term.ReplaceLatest(l)
+		}
+		switch {
+		case l == "history":
+			h := term.History()
+			slices.Reverse(h)
+			for i, v := range h {
+				fmt.Fprintf(term.Out, "%02d: %s\n", i+1, v)
+			}
+			continue
+		case l == "help":
+			fmt.Fprintln(term.Out, "Type 'history' to see history, '!n' to repeat history n, 'info' for language builtins")
+			continue
 		}
-		l := prev + scanner.Text()
 		// errors are already logged and this is the only case that can get contNeeded (EOL instead of EOF mode)
-		contNeeded, _, _ := EvalOne(s, macroState, l, out, options)
+		contNeeded, _, formatted := EvalOne(s, macroState, l, term.Out, options)
 		if contNeeded {
 			prev = l + "\n"
-			prompt = CONTINUATION
+			term.SetPrompt(CONTINUATION)
 		} else {
+			if prev != "" {
+				// In addition to raw lines, we also add the single line version to history.
+				log.LogVf("Adding to history: %q", formatted)
+				term.AddToHistory(formatted)
+			}
 			prev = ""
-			prompt = PROMPT
+			term.SetPrompt(PROMPT)
 		}
 	}
 }