Added a new command

lamb/commands.py

@@ -36,7 +36,7 @@ def cmd_save(command, runner) -> None:
 	if len(command.args) != 1:
 		printf(
 			HTML(
-				"<err>Command <cmd_code>:{command.name}</cmd_code> takes exactly one argument.</err>"
+				f"<err>Command <cmd_code>:{command.name}</cmd_code> takes exactly one argument.</err>"
 			),
 			style = lamb.utils.style
 		)
@@ -81,7 +81,7 @@ def cmd_load(command, runner):
 	if len(command.args) != 1:
 		printf(
 			HTML(
-				"<err>Command <cmd_code>:{command.name}</cmd_code> takes exactly one argument.</err>"
+				f"<err>Command <cmd_code>:{command.name}</cmd_code> takes exactly one argument.</err>"
 			),
 			style = lamb.utils.style
 		)
@@ -145,7 +145,7 @@ def mdel(command, runner) -> None:
 	if len(command.args) != 1:
 		printf(
 			HTML(
-				"<err>Command <cmd_code>:{command.name}</cmd_code> takes exactly one argument.</err>"
+				f"<err>Command <cmd_code>:{command.name}</cmd_code> takes exactly one argument.</err>"
 			),
 			style = lamb.utils.style
 		)
@@ -185,6 +185,76 @@ def clear(command, runner) -> None:
 	clear_screen()
 	lamb.utils.show_greeting()
 
+@lamb_command(
+	help_text = "Get or set reduction limit"
+)
+def rlimit(command, runner) -> None:
+	if len(command.args) == 0:
+		if runner.reduction_limit is None:
+			printf(
+				HTML(
+					"<ok>No reduction limit is set</ok>"
+				),
+				style = lamb.utils.style
+			)
+		else:
+			printf(
+				HTML(
+					f"<ok>Reduction limit is {runner.reduction_limit:,}</ok>"
+				),
+				style = lamb.utils.style
+			)
+		return
+
+	elif len(command.args) != 1:
+		printf(
+			HTML(
+				f"<err>Command <cmd_code>:{command.name}</cmd_code> takes exactly one argument.</err>"
+			),
+			style = lamb.utils.style
+		)
+		return
+
+	t = command.args[0]
+	if t.lower() == "none":
+		runner.reduction_limit = None
+		printf(
+			HTML(
+				f"<ok>Removed reduction limit</ok>"
+			),
+			style = lamb.utils.style
+		)
+		return
+
+	try:
+		t = int(t)
+	except ValueError:
+		printf(
+			HTML(
+				"<err>Reduction limit must be a positive integer or \"none\".</err>"
+			),
+			style = lamb.utils.style
+		)
+		return
+
+	if 50 > t:
+		printf(
+			HTML(
+				"<err>Reduction limit must be at least 50.</err>"
+			),
+			style = lamb.utils.style
+		)
+		return
+
+	runner.reduction_limit = t
+	printf(
+		HTML(
+			f"<ok>Set reduction limit to {t:,}</ok>"
+		),
+		style = lamb.utils.style
+	)
+
+
 
 @lamb_command(
 	help_text = "Print this help"

lamb/parser.py

@@ -54,7 +54,7 @@ class LambdaParser:
 			(self.lp + self.pp_call + self.rp)
 		)
 
-		self.pp_command = pp.Suppress(":") + pp.Word(pp.alphas + "_") + pp.Word(pp.alphas + "_")[0, ...]
+		self.pp_command = pp.Suppress(":") + pp.Word(pp.alphas + "_") + pp.Word(pp.alphas + pp.nums + "_")[0, ...]
 
 
 		self.pp_all = (

lamb/runner.py

@@ -1,7 +1,6 @@
 from prompt_toolkit import PromptSession
 from prompt_toolkit.formatted_text import FormattedText
 from prompt_toolkit import print_formatted_text as printf
-from prompt_toolkit.shortcuts import clear as clear_screen
 import enum
 import math
 import time
@@ -86,7 +85,9 @@ class Runner:
 		self.iter_update = 231
 
 	def prompt(self):
-		return self.prompt_session.prompt(message = self.prompt_message)
+		return self.prompt_session.prompt(
+			message = self.prompt_message
+		)
 
 	def parse(self, line):
 		e = self.parser.parse_line(line)
@@ -151,7 +152,8 @@ class Runner:
 			("class:text", str(macro_expansions)),
 
 			("class:result_header", f"\nReductions: "),
-			("class:text", str(i))
+			("class:text", f"{i}    "),
+			("class:muted", f"(Limit: {self.reduction_limit:,})")
 		]
 
 		if (stop_reason == StopReason.BETA_NORMAL or stop_reason == StopReason.LOOP_DETECTED):

lamb/utils.py

@@ -11,6 +11,7 @@ style = Style.from_dict({ # type: ignore
 	"err": "#FF0000",
 	"prompt": "#00FFFF",
 	"ok": "#B4EC85",
+	"muted": "#AAAAAA",
 
 	# Syntax
 	"syn_macro": "#FF00FF",