feat: control k to delete the rest of the line (#128)

Co-authored-by: Renzix <DanielDeBruno@renzix.com>

api.go

@@ -28,6 +28,7 @@ var exports = map[string]lua.LGFunction {
 	"exec": hlexec,
 	"runnerMode": hlrunnerMode,
 	"goro": hlgoro,
+	"highlighter": hlhighlighter,
 	"hinter": hlhinter,
 	"multiprompt": hlmlprompt,
 	"prependPath": hlprependPath,
@@ -517,3 +518,16 @@ func hlhinter(L *lua.LState) int {
 	
 	return 0
 }
+
+// highlighter(cb)
+// Sets the highlighter function. This is mainly for syntax hightlighting, but in
+// reality could set the input of the prompt to display anything. The callback
+// is passed the current line as typed and is expected to return a line that will
+// be used to display in the line.
+// --- @param cb function
+func hlhighlighter(L *lua.LState) int {
+	highlighterCb := L.CheckFunction(1)
+	highlighter = highlighterCb
+
+	return 0
+}

docs/hilbish.txt

@@ -16,6 +16,11 @@ exec(cmd) > Replaces running hilbish with `cmd`
 
 goro(fn) > Puts `fn` in a goroutine
 
+highlighter(cb) > Sets the highlighter function. This is mainly for syntax hightlighting, but in
+reality could set the input of the prompt to display anything. The callback
+is passed the current line as typed and is expected to return a line that will
+be used to display in the line.
+
 hinter(cb) > Sets the hinter function. This will be called on every key insert to determine
 what text to use as an inline hint. The callback is passed 2 arguments:
 the current line and the position. It is expected to return a string

emmyLuaDocs/hilbish.lua

@@ -33,6 +33,13 @@ function hilbish.exec(cmd) end
 --- @param fn function
 function hilbish.goro(fn) end
 
+--- Sets the highlighter function. This is mainly for syntax hightlighting, but in
+--- reality could set the input of the prompt to display anything. The callback
+--- is passed the current line as typed and is expected to return a line that will
+--- be used to display in the line.
+--- @param cb function
+function hilbish.highlighter(cb) end
+
 --- Sets the hinter function. This will be called on every key insert to determine
 --- what text to use as an inline hint. The callback is passed 2 arguments:
 --- the current line and the position. It is expected to return a string

readline/line.go

@@ -176,3 +176,9 @@ func (rl *Instance) deleteToBeginning() {
 	rl.line = rl.line[rl.pos:]
 	rl.pos = 0
 }
+
+func (rl *Instance) deleteToEnd() {
+	rl.resetVirtualComp(false)
+	// Keep everything before the cursor
+	rl.line = rl.line[:rl.pos]
+}

readline/readline.go

@@ -189,6 +189,16 @@ func (rl *Instance) Readline() (string, error) {
 			rl.resetHelpers()
 			rl.updateHelpers()
 
+		case charCtrlK:
+			if rl.modeTabCompletion {
+				rl.resetVirtualComp(true)
+			}
+			// Delete everything after the cursor position
+			rl.saveBufToRegister(rl.line[rl.pos:])
+			rl.deleteToEnd()
+			rl.resetHelpers()
+			rl.updateHelpers()
+
 		case charBackspace, charBackspace2:
 			// When currently in history completion, we refresh and automatically
 			// insert the first (filtered) candidate, virtually

rl.go

@@ -13,7 +13,8 @@ type lineReader struct {
 	rl *readline.Instance
 }
 var fileHist *fileHistory
-var hinter lua.LValue
+var hinter lua.LValue = lua.LNil
+var highlighter lua.LValue = lua.LNil
 
 // other gophers might hate this naming but this is local, shut up
 func newLineReader(prompt string, noHist bool) *lineReader {
@@ -46,6 +47,10 @@ func newLineReader(prompt string, noHist bool) *lineReader {
 		hooks.Em.Emit("hilbish.vimAction", actionStr, args)
 	}
 	rl.HintText = func(line []rune, pos int) []rune {
+		if hinter == lua.LNil {
+			return []rune{}
+		}
+
 		err := l.CallByParam(lua.P{
 			Fn: hinter,
 			NRet: 1,
@@ -64,6 +69,28 @@ func newLineReader(prompt string, noHist bool) *lineReader {
 		
 		return []rune(hintText)
 	}
+	rl.SyntaxHighlighter = func(line []rune) string {
+		if highlighter == lua.LNil {
+			return string(line)
+		}
+		err := l.CallByParam(lua.P{
+			Fn: highlighter,
+			NRet: 1,
+			Protect: true,
+		}, lua.LString(string(line)))
+		if err != nil {
+			fmt.Println(err)
+			return string(line)
+		}
+		
+		retVal := l.Get(-1)
+		highlighted := ""
+		if luaStr, ok := retVal.(lua.LString); retVal != lua.LNil && ok {
+			highlighted = luaStr.String()
+		}
+		
+		return highlighted
+	}
 	rl.TabCompleter = func(line []rune, pos int, _ readline.DelayedTabContext) (string, []*readline.CompletionGroup) {
 		ctx := string(line)
 		var completions []string