add support for cancelling the current statement in the console / a r…

…unning program with Ctrl-C (closes #8)
xrstf · Dec 21, 2023 · f247c71 · f247c71
1 parent 226486b
commit f247c71
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Showing 4 changed files with 31 additions and 13 deletions.
diff --git a/cmd/rudi/cmd/console/command.go b/cmd/rudi/cmd/console/command.go
@@ -47,7 +47,7 @@ var replCommands = map[string]replCommandFunc{
  "help": helpCommand,
 }
 
-func Run(ctx context.Context, opts *cmdtypes.Options, args []string, rudiVersion string) error {
+func Run(handler *util.SignalHandler, opts *cmdtypes.Options, args []string, rudiVersion string) error {
  rl, err := readline.New("⮞ ")
  if err != nil {
  return fmt.Errorf("failed to setup readline prompt: %w", err)
@@ -69,15 +69,23 @@ func Run(ctx context.Context, opts *cmdtypes.Options, args []string, rudiVersion
 
  for {
  line, err := rl.Readline()
- if err != nil { // io.EOF
+
+ // treat interrupts as "clear input"
+ if errors.Is(err, readline.ErrInterrupt) {
+ continue
+ }
+
+ // io.EOF (Ctrl-D)
+ if err != nil {
  break
  }
+
  line = strings.TrimSpace(line)
  if line == "" {
  continue
  }
 
- newCtx, stop, err := processInput(ctx, rudiCtx, opts, line)
+ newCtx, stop, err := processInput(handler, rudiCtx, opts, line)
  if err != nil {
  parseErr := &rudi.ParseError{}
  if errors.As(err, parseErr) {
@@ -99,7 +107,7 @@ func Run(ctx context.Context, opts *cmdtypes.Options, args []string, rudiVersion
  return nil
 }
 
-func processInput(ctx context.Context, rudiCtx types.Context, opts *cmdtypes.Options, input string) (newCtx types.Context, stop bool, err error) {
+func processInput(handler *util.SignalHandler, rudiCtx types.Context, opts *cmdtypes.Options, input string) (newCtx types.Context, stop bool, err error) {
  if command, exists := replCommands[input]; exists {
  return rudiCtx, false, command(rudiCtx, opts)
  }
@@ -119,7 +127,11 @@ func processInput(ctx context.Context, rudiCtx types.Context, opts *cmdtypes.Opt
  return rudiCtx, false, err
  }
 
- // TODO: Setup a new context that can be cancelled with Ctrl-C to interrupt long running statements.
+ // allow to interrupt the statement
+ ctx, cancel := context.WithCancel(context.Background())
+ defer cancel()
+
+ handler.SetCancelFn(cancel)
 
  newCtx, evaluated, err := program.RunContext(rudiCtx.WithGoContext(ctx))
  if err != nil {

diff --git a/cmd/rudi/cmd/script/command.go b/cmd/rudi/cmd/script/command.go
@@ -11,16 +11,16 @@ import (
  "os"
  "strings"
 
- "github.com/BurntSushi/toml"
  "go.xrstf.de/rudi"
  "go.xrstf.de/rudi/cmd/rudi/types"
  "go.xrstf.de/rudi/cmd/rudi/util"
  "go.xrstf.de/rudi/pkg/debug"
 
+ "github.com/BurntSushi/toml"
  "gopkg.in/yaml.v3"
 )
 
-func Run(ctx context.Context, opts *types.Options, args []string) error {
+func Run(handler *util.SignalHandler, opts *types.Options, args []string) error {
  // determine input script to evaluate
  var (
  script string
@@ -73,8 +73,14 @@ func Run(ctx context.Context, opts *types.Options, args []string) error {
  return fmt.Errorf("failed to setup context: %w", err)
  }
 
+ // allow to interrupt the script
+ subCtx, cancel := context.WithCancel(context.Background())
+ defer cancel()
+
+ handler.SetCancelFn(cancel)
+
  // evaluate the script
- _, evaluated, err := program.RunContext(rudiCtx.WithGoContext(ctx))
+ _, evaluated, err := program.RunContext(rudiCtx.WithGoContext(subCtx))
  if err != nil {
  return fmt.Errorf("failed to evaluate script: %w", err)
  }

diff --git a/cmd/rudi/main.go b/cmd/rudi/main.go
@@ -4,7 +4,6 @@
 package main
 
 import (
- "context"
  "errors"
  "fmt"
  "os"
@@ -17,6 +16,7 @@ import (
  "go.xrstf.de/rudi/cmd/rudi/cmd/help"
  "go.xrstf.de/rudi/cmd/rudi/cmd/script"
  "go.xrstf.de/rudi/cmd/rudi/types"
+ "go.xrstf.de/rudi/cmd/rudi/util"
 
  "github.com/spf13/pflag"
 )
@@ -112,18 +112,18 @@ func main() {
  return
  }
 
- ctx := context.Background()
+ handler := util.SetupSignalHandler()
 
  if opts.Interactive || len(args) == 0 {
- if err := console.Run(ctx, &opts, args, BuildTag); err != nil {
+ if err := console.Run(handler, &opts, args, BuildTag); err != nil {
  fmt.Printf("Error: %v\n", err)
  os.Exit(1)
  }
 
  return
  }
 
- if err := script.Run(ctx, &opts, args); err != nil {
+ if err := script.Run(handler, &opts, args); err != nil {
  parseErr := &rudi.ParseError{}
  if errors.As(err, parseErr) {
  fmt.Println(parseErr.Snippet())

diff --git a/cmd/rudi/util/files.go b/cmd/rudi/util/files.go
@@ -11,9 +11,9 @@ import (
  "path/filepath"
  "strings"
 
- "github.com/BurntSushi/toml"
  "go.xrstf.de/rudi/cmd/rudi/types"
 
+ "github.com/BurntSushi/toml"
  "gopkg.in/yaml.v3"
 )