Merge branch 'master' of https://github.com/rm-dr/lamb

.gitignore

@@ -1,7 +1,13 @@
+# Python dev files
 venv
 __pycache__
 
+# Python build files
 *.egg-info
 *.spec
 build
-dist
+dist
+
+# Misc
+*.gif
+misc/secrets.sh

.vscode/settings.json

@@ -1,5 +1,6 @@
 {
     "cSpell.words": [
+        "appendleft",
         "autochurch",
         "delmac",
         "Endnodes",
@@ -7,6 +8,7 @@
         "mdel",
         "onefile",
         "Packrat",
+        "printables",
         "pyparsing",
         "rlimit",
         "runstatus",

README.md

@@ -1,26 +1,43 @@
-# Lamb: A Lambda Calculus Engine
+# 🐑 Lamb: A Lambda Calculus Engine
 
-![Lamb screenshot](./misc/screenshot.png)
+![Lamb Demo](https://github.com/rm-dr/lamb/assets/96270320/d518e344-e7c8-47ed-89c4-7ce273bf4e2d)
 
-## Installation
 
-### Method 1: PyPi (not yet)
-1. Put this on PyPi
-2. Write these instructions
+
+## :brain: What is lambda calculus?
+
+ - [video 1](https://www.youtube.com/watch?v=3VQ382QG-y4): Introduction and boolean logic. The first few minutes are a bit confusing, but it starts to make sense at about [`6:50`](https://youtu.be/3VQ382QG-y4?t=400)
+
+ - [video 2](https://www.youtube.com/watch?v=pAnLQ9jwN-E): Continuation of video 1. Features combinators and numerals.
+
+ - [blog](https://www.driverlesscrocodile.com/technology/lambda-calculus-for-people-a-step-behind-me-1): Another introduction. Moves slower than the two videos above and doesn't assume CS knowledge. Four-part series.
+
+ - [handout](https://static.betalupi.com/ormc/Advanced/Lambda%20Calculus.pdf): A handout I've written on lambda calculus.
+
+## :package: Installation
+
+### Method 1: [PyPi](https://pypi.org/project/lamb-engine)
+1. *(Optional but recommended)* make and enter a [venv](https://docs.python.org/3/library/venv.html)
+	- **On Windows, run the following in cmd or powershell:**
+	- `cd Desktop`
+	- `python -m venv lamb`
+	- `.\Scripts\activate`
+2. `pip install lamb-engine`
+3. `lamb`
 
 ### Method 2: Git
 1. Clone this repository.
 2. Make and enter a [virtual environment](https://docs.python.org/3/library/venv.html).
 3. ``cd`` into this directory
 4. Run ``pip install .``
-5. Run ``python .``
+5. Run ``lamb``
 
 -------------------------------------------------
 
-## Usage
+## 📖 Usage
 
 
-Type lambda expressions into the prompt, and Lamb will evaluate them. \
+Type expressions into the prompt, and Lamb will evaluate them. \
 Use your `\` (backslash) key to type a `λ`. \
 To define macros, use `=`. For example,
 ```
@@ -43,35 +60,47 @@ Numbers will automatically be converted to Church numerals. For example, the fol
 If an expression takes too long to evaluate, you may interrupt reduction with `Ctrl-C`. \
 Exit the prompt with `Ctrl-C` or `Ctrl-D`.
 
-There are many useful macros in [macros.lamb](./macros.lamb). Load them with the `:load` command:
+There are many useful macros in [macros.lamb](./macros.lamb). Download the file, then load them with the `:load` command:
 ```
 ==> :load macros.lamb
 ```
 
+You can also pass files to lamb directly to have them loaded at startup:
+```
+lamb file1 file2
+```
+
+Use your up/down arrows to recall history.
+
 Have fun!
 
 -------------------------------------------------
 
-## Commands
+## :card_file_box: Commands
 
 Lamb understands many commands. Prefix them with a `:` in the prompt.
 
-`:help` Prints a help message
+`:help` Print a help message
 
 `:clear` Clear the screen
 
 `:rlimit [int | None]` Set maximum reduction limit. `:rlimit none` sets no limit.
 
-`:macros` List macros in the current environment.
+`:macros` List macros.
 
 `:mdel [macro]` Delete a macro
 
-`:step [yes | no]` Enable or disable step-by-step reduction. Toggle if no argument is given.
+`:delmac` Delete all macros
+
+`:step [yes | no]` Enable or disable step-by-step reduction. Toggle if no argument is given. When reducing by steps, the prompt tells you what kind of reduction was done last:
+
+ - `M`: Macro expansion
+ - `C`: Church expansion
+ - `H`: History expansion
+ - `F`: Function application
 
 `:expand [yes | no]` Enable or disable full expansion. Toggle if no argument is given. If full expansion is enabled, ALL macros will be expanded when printing output.
 
-`:delmac` Delete all macros
-
 `:save [filename]` \
 `:load [filename]` \
 Save or load macros from a file.
@@ -79,26 +108,12 @@ The lines in a file look exactly the same as regular entries in the prompt, but
 
 -------------------------------------------------
 
-
-## Todo (pre-release, in this order):
- - History queue
- - Prevent macro-chaining recursion
- - Update screenshot
- - Update documentation
- - Write "how it works"
- - PyPi package
-
-
 ## Todo:
+ - Prevent macro-chaining recursion
  - Cleanup warnings
- - Syntax highlight printouts
  - Truncate long expressions in warnings
- - History indexing
- - Show history command
  - Loop detection
- - $\alpha$-equivalence check
- - Command-line options (load a file)
  - Unchurch command: make church numerals human-readable
- - Better Syntax highlighting
- - Complete file names and commands
- - Tests
+ - Better syntax highlighting
+ - Tab-complete file names and commands
+ - Load default macros without manually downloading `macros.lamb` (via `requests`, maybe?)

build_bin.py

@@ -1,10 +0,0 @@
-import PyInstaller.__main__
-
-# Run this file to build a standalone executable.
-# pyinstaller does not build cross-platform.
-
-PyInstaller.__main__.run([
-	"lamb/__main__.py",
-	"--onefile",
-	"--console"
-])

lamb/__main__.py

@@ -1,61 +0,0 @@
-if __name__ != "__main__":
-	raise ImportError("lamb.__main__ should never be imported. Run it directly.")
-
-from prompt_toolkit import PromptSession
-from prompt_toolkit import print_formatted_text as printf
-from prompt_toolkit.formatted_text import FormattedText
-from prompt_toolkit.formatted_text import to_plain_text
-from pyparsing import exceptions as ppx
-
-import lamb
-
-
-lamb.utils.show_greeting()
-
-
-r = lamb.Runner(
-	prompt_session = PromptSession(
-		style = lamb.utils.style,
-		lexer = lamb.utils.LambdaLexer(),
-		key_bindings = lamb.utils.bindings
-	),
-	prompt_message = FormattedText([
-		("class:prompt", "==> ")
-	])
-)
-
-while True:
-	try:
-		i = r.prompt()
-
-	# Catch Ctrl-C and Ctrl-D
-	except KeyboardInterrupt:
-		printf("\n\nGoodbye.\n")
-		break
-	except EOFError:
-		printf("\n\nGoodbye.\n")
-		break
-
-	# Skip empty lines
-	if i.strip() == "":
-		continue
-
-	# Try to run an input line.
-	# Catch parse errors and point them out.
-	try:
-		x = r.run(i)
-	except ppx.ParseException as e:
-		l = len(to_plain_text(r.prompt_session.message))
-		printf(FormattedText([
-			("class:err", " "*(e.loc + l) + "^\n"),
-			("class:err", f"Syntax error at char {e.loc}."),
-			("class:text", "\n")
-		]), style = lamb.utils.style)
-		continue
-	except lamb.nodes.ReductionError as e:
-		printf(FormattedText([
-			("class:err", f"{e.msg}\n")
-		]), style = lamb.utils.style)
-		continue
-
-	printf("")

lamb_engine/__init__.py

@@ -3,4 +3,6 @@ from . import nodes
 from . import parser
 
 from .runner import Runner
-from .runner import StopReason
+from .runner import StopReason
+
+from .__main__ import main

lamb_engine/__main__.py

@@ -0,0 +1,79 @@
+from prompt_toolkit import PromptSession
+from prompt_toolkit import print_formatted_text as printf
+from prompt_toolkit.formatted_text import FormattedText
+from prompt_toolkit.formatted_text import to_plain_text
+from pyparsing import exceptions as ppx
+import sys
+
+import lamb_engine
+
+def main():
+
+	lamb_engine.utils.show_greeting()
+
+
+	r = lamb_engine.Runner(
+		prompt_session = PromptSession(
+			style = lamb_engine.utils.style,
+			lexer = lamb_engine.utils.LambdaLexer(),
+			key_bindings = lamb_engine.utils.bindings
+		),
+		prompt_message = FormattedText([
+			("class:prompt", "==> ")
+		])
+	)
+
+	# Load files passed as arguments
+	if len(sys.argv) > 1:
+		for i in range(1, len(sys.argv)):
+			try:
+				printf(FormattedText([
+					("class:warn", "\nLoading file "),
+					("class:code", sys.argv[i]),
+				]), style = lamb_engine.utils.style)
+				r.run(":load " + sys.argv[i])
+			except:
+				printf(FormattedText([
+					("class:err", "Error. Does this file exist?"),
+				]), style = lamb_engine.utils.style)
+
+		print("")
+
+	while True:
+		try:
+			i = r.prompt()
+
+		# Catch Ctrl-C and Ctrl-D
+		except KeyboardInterrupt:
+			printf("\n\nGoodbye.\n")
+			break
+		except EOFError:
+			printf("\n\nGoodbye.\n")
+			break
+
+		# Skip empty lines
+		if i.strip() == "":
+			continue
+
+		# Try to run an input line.
+		# Catch parse errors and point them out.
+		try:
+			x = r.run(i)
+		except ppx.ParseException as e:
+			l = len(to_plain_text(r.prompt_session.message))
+			printf(FormattedText([
+				("class:err", " "*(e.loc + l) + "^\n"),
+				("class:err", f"Syntax error at char {e.loc}."),
+				("class:text", "\n")
+			]), style = lamb_engine.utils.style)
+			continue
+		except lamb_engine.nodes.ReductionError as e:
+			printf(FormattedText([
+				("class:err", f"{e.msg}\n")
+			]), style = lamb_engine.utils.style)
+			continue
+
+		printf("")
+
+if __name__ == "__main__":
+	main()

lamb_engine/nodes/functions.py

@@ -1,5 +1,5 @@
-import lamb
-import lamb.nodes as lbn
+import lamb_engine
+import lamb_engine.nodes as lbn
 
 def print_node(node: lbn.Node, *, export: bool = False) -> str:
 	if not isinstance(node, lbn.Node):
@@ -28,7 +28,7 @@ def print_node(node: lbn.Node, *, export: bool = False) -> str:
 					i = -1
 					p = o
 					while o in bound_subs.values():
-						o = p + lamb.utils.subscript(i := i + 1)
+						o = p + lamb_engine.utils.subscript(i := i + 1)
 					bound_subs[n.input.identifier] = o
 				else:
 					bound_subs[n.input.identifier] = n.input.print_value()
@@ -162,14 +162,13 @@ def prepare(root: lbn.Root, *, ban_macro_name = None) -> list:
 	it = iter(root)
 	for s, n in it:
 		if isinstance(n, lbn.History):
-			if len(root.runner.history) == 0:
+			if root.runner.history[0] == None:
 				raise lbn.ReductionError("There isn't any history to reference.")
 			else:
 				warnings += [
 					("class:code", "$"),
-					("class:warn", " will be expanded to "),
-					("class:code", f"{n.expand()[1]}\n"),
-				]
+					("class:warn", " will be expanded to ")
+				] + lamb_engine.utils.lex_str(str(n.expand()[1]))
 
 		# If this expression is part of a macro,
 		# make sure we don't reference it inside itself.
@@ -209,7 +208,7 @@ def prepare(root: lbn.Root, *, ban_macro_name = None) -> list:
 					raise lbn.ReductionError(f"Bound variable name conflict: \"{n.input.name}\"")
 				else:
 					bound_variables[n.input.name] = lbn.Bound(
-						lamb.utils.remove_sub(n.input.name),
+						lamb_engine.utils.remove_sub(n.input.name),
 						macro_name = n.input.name
 					)
 					n.input = bound_variables[n.input.name]

lamb_engine/nodes/nodes.py

@@ -1,5 +1,5 @@
-import lamb
-import lamb.nodes as lbn
+import lamb_engine
+import lamb_engine.nodes as lbn
 
 class TreeWalker:
 	"""
@@ -77,12 +77,12 @@ class Node:
 		self.parent_side: Direction = None # type: ignore
 
 		# Left and right nodes, None if empty
-		self._left: Node | None = None
-		self._right: Node | None = None
+		self._left = None
+		self._right = None
 
 		# The runner this node is attached to.
 		# Set by Node.set_runner()
-		self.runner: lamb.runner.Runner = None # type: ignore
+		self.runner: lamb_engine.runner.Runner = None # type: ignore
 
 	def __iter__(self):
 		return TreeWalker(self)
@@ -321,12 +321,12 @@ class History(ExpandableEndNode):
 	def expand(self) -> tuple[lbn.ReductionType, Node]:
 		# We shouldn't ever get here, prepare()
 		# catches empty history.
-		if len(self.runner.history) == 0:
+		if self.runner.history[0] == None:
 			raise Exception(f"Tried to expand empty history.")
 		# .left is VERY important!
 		# self.runner.history will contain Root nodes,
 		# and we don't want those *inside* our tree.
-		return lbn.ReductionType.HIST_EXPAND, lbn.clone(self.runner.history[-1].left)
+		return lbn.ReductionType.HIST_EXPAND, lbn.clone(self.runner.history[0].left)
 
 	def copy(self):
 		return History(runner = self.runner)
@@ -341,7 +341,7 @@ class Bound(EndNode):
 		# The name of the macro this bound came from.
 		# Always equal to self.name, unless the macro
 		# this came from had a subscript.
-		self.macro_name: str | None = macro_name
+		self.macro_name = macro_name
 
 		if forced_id is None:
 			self.identifier = bound_counter
@@ -381,9 +381,9 @@ class Func(Node):
 				Func.from_parse(result)
 			)
 
-	def __init__(self, input: Macro | Bound, output: Node, *, runner = None) -> None:
+	def __init__(self, input, output: Node, *, runner = None) -> None:
 		super().__init__()
-		self.input: Macro | Bound = input
+		self.input = input
 		self.left: Node = output
 		self.right: None = None
 		self.runner = runner # type: ignore

lamb_engine/parser.py

@@ -56,7 +56,7 @@ class LambdaParser:
 			(self.lp + self.pp_history + self.rp)
 		)
 
-		self.pp_command = pp.Suppress(":") + pp.Word(pp.alphas + "_") + pp.Word(pp.alphas + pp.nums + "_.")[0, ...]
+		self.pp_command = pp.Suppress(":") + pp.Word(pp.alphas + "_") + pp.Word(pp.printables)[0, ...]
 
 
 		self.pp_all = (

lamb_engine/runner/commands.py

@@ -7,14 +7,14 @@ from prompt_toolkit import prompt
 import os.path
 from pyparsing import exceptions as ppx
 
-import lamb
+import lamb_engine
 
 commands = {}
 help_texts = {}
 
 def lamb_command(
 		*,
-		command_name: str | None = None,
+		command_name = None,
 		help_text: str
 	):
 	"""
@@ -38,7 +38,7 @@ def cmd_step(command, runner) -> None:
 			HTML(
 				f"<err>Command <code>:{command.name}</code> takes no more than one argument.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -53,7 +53,7 @@ def cmd_step(command, runner) -> None:
 				HTML(
 					f"<err>Usage: <code>:step [yes|no]</code></err>"
 				),
-				style = lamb.utils.style
+				style = lamb_engine.utils.style
 			)
 			return
 
@@ -63,7 +63,7 @@ def cmd_step(command, runner) -> None:
 			HTML(
 				f"<warn>Enabled step-by-step reduction.</warn>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		runner.step_reduction = True
 	else:
@@ -71,7 +71,7 @@ def cmd_step(command, runner) -> None:
 			HTML(
 				f"<warn>Disabled step-by-step reduction.</warn>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		runner.step_reduction = False
 
@@ -85,7 +85,7 @@ def cmd_expand(command, runner) -> None:
 			HTML(
 				f"<err>Command <code>:{command.name}</code> takes no more than one argument.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -100,7 +100,7 @@ def cmd_expand(command, runner) -> None:
 				HTML(
 					f"<err>Usage: <code>:expand [yes|no]</code></err>"
 				),
-				style = lamb.utils.style
+				style = lamb_engine.utils.style
 			)
 			return
 
@@ -110,7 +110,7 @@ def cmd_expand(command, runner) -> None:
 			HTML(
 				f"<warn>Enabled complete expansion.</warn>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		runner.full_expansion = True
 	else:
@@ -118,7 +118,7 @@ def cmd_expand(command, runner) -> None:
 			HTML(
 				f"<warn>Disabled complete expansion.</warn>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		runner.full_expansion = False
 
@@ -133,7 +133,7 @@ def cmd_save(command, runner) -> None:
 			HTML(
 				f"<err>Command <code>:{command.name}</code> takes exactly one argument.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -144,7 +144,7 @@ def cmd_save(command, runner) -> None:
 				("class:warn", "File exists. Overwrite? "),
 				("class:text", "[yes/no]: ")
 			]),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		).lower()
 
 		if confirm != "yes":
@@ -152,7 +152,7 @@ def cmd_save(command, runner) -> None:
 				HTML(
 					"<err>Cancelled.</err>"
 				),
-				style = lamb.utils.style
+				style = lamb_engine.utils.style
 			)
 			return
 
@@ -165,7 +165,7 @@ def cmd_save(command, runner) -> None:
 		HTML(
 			f"Wrote {len(runner.macro_table)} macros to <code>{target}</code>"
 		),
-		style = lamb.utils.style
+		style = lamb_engine.utils.style
 	)
 
 
@@ -179,7 +179,7 @@ def cmd_load(command, runner):
 			HTML(
 				f"<err>Command <code>:{command.name}</code> takes exactly one argument.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -189,7 +189,7 @@ def cmd_load(command, runner):
 			HTML(
 				f"<err>File {target} doesn't exist.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -215,18 +215,18 @@ def cmd_load(command, runner):
 					("class:err", l[e.loc]),
 					("class:code", l[e.loc+1:])
 				]),
-				style = lamb.utils.style
+				style = lamb_engine.utils.style
 			)
 			return
 
-		if not isinstance(x, lamb.runner.runner.MacroDef):
+		if not isinstance(x, lamb_engine.runner.runner.MacroDef):
 			printf(
 				FormattedText([
 					("class:warn", f"Skipping line {i+1:02}: "),
 					("class:code", l),
 					("class:warn", f" is not a macro definition.")
 				]),
-				style = lamb.utils.style
+				style = lamb_engine.utils.style
 			)
 			return
 
@@ -234,10 +234,9 @@ def cmd_load(command, runner):
 
 		printf(
 			FormattedText([
-				("class:ok", f"Loaded {x.label}: "),
-				("class:code", str(x.expr))
-			]),
-			style = lamb.utils.style
+				("class:ok", f"Loaded {x.label}: ")
+			] + lamb_engine.utils.lex_str(str(x.expr))),
+			style = lamb_engine.utils.style
 		)
 
 
@@ -250,7 +249,7 @@ def mdel(command, runner) -> None:
 			HTML(
 				f"<err>Command <code>:{command.name}</code> takes exactly one argument.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -260,7 +259,7 @@ def mdel(command, runner) -> None:
 			HTML(
 				f"<warn>Macro \"{target}\" is not defined</warn>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -275,7 +274,7 @@ def delmac(command, runner) -> None:
 			("class:warn", "Are you sure? "),
 			("class:text", "[yes/no]: ")
 		]),
-		style = lamb.utils.style
+		style = lamb_engine.utils.style
 	).lower()
 
 	if confirm != "yes":
@@ -283,7 +282,7 @@ def delmac(command, runner) -> None:
 			HTML(
 				"<err>Cancelled.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -298,7 +297,7 @@ def macros(command, runner) -> None:
 		printf(FormattedText([
 				("class:warn", "No macros are defined."),
 			]),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 	else:
 		printf(FormattedText([
@@ -308,7 +307,7 @@ def macros(command, runner) -> None:
 				("class:text", f"\t{name} \t {exp}\n")
 				for name, exp in runner.macro_table.items()
 			]),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 
 @lamb_command(
@@ -316,7 +315,7 @@ def macros(command, runner) -> None:
 )
 def clear(command, runner) -> None:
 	clear_screen()
-	lamb.utils.show_greeting()
+	lamb_engine.utils.show_greeting()
 
 @lamb_command(
 	help_text = "Get or set reduction limit"
@@ -328,14 +327,14 @@ def rlimit(command, runner) -> None:
 				HTML(
 					"<ok>No reduction limit is set</ok>"
 				),
-				style = lamb.utils.style
+				style = lamb_engine.utils.style
 			)
 		else:
 			printf(
 				HTML(
 					f"<ok>Reduction limit is {runner.reduction_limit:,}</ok>"
 				),
-				style = lamb.utils.style
+				style = lamb_engine.utils.style
 			)
 		return
 
@@ -344,7 +343,7 @@ def rlimit(command, runner) -> None:
 			HTML(
 				f"<err>Command <code>:{command.name}</code> takes exactly one argument.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -355,7 +354,7 @@ def rlimit(command, runner) -> None:
 			HTML(
 				f"<ok>Removed reduction limit</ok>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -366,7 +365,7 @@ def rlimit(command, runner) -> None:
 			HTML(
 				"<err>Reduction limit must be a positive integer or \"none\".</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -375,7 +374,7 @@ def rlimit(command, runner) -> None:
 			HTML(
 				"<err>Reduction limit must be at least 50.</err>"
 			),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 		return
 
@@ -384,7 +383,7 @@ def rlimit(command, runner) -> None:
 		HTML(
 			f"<ok>Set reduction limit to {t:,}</ok>"
 		),
-		style = lamb.utils.style
+		style = lamb_engine.utils.style
 	)
 
 
@@ -417,5 +416,5 @@ def help(command, runner) -> None:
 			"<muted>Detailed documentation can be found on this project's git page.</muted>" +
 			"</text>"
 		),
-		style = lamb.utils.style
+		style = lamb_engine.utils.style
 	)

lamb_engine/runner/misc.py

@@ -1,5 +1,5 @@
 import enum
-import lamb
+import lamb_engine
 
 class StopReason(enum.Enum):
 	BETA_NORMAL		= ("class:text", "β-normal form")
@@ -16,7 +16,7 @@ class MacroDef:
 			result[1]
 		)
 
-	def __init__(self, label: str, expr: lamb.nodes.Node):
+	def __init__(self, label: str, expr: lamb_engine.nodes.Node):
 		self.label = label
 		self.expr = expr
 

lamb_engine/runner/runner.py

@@ -3,16 +3,16 @@ from prompt_toolkit.formatted_text import FormattedText
 from prompt_toolkit.key_binding import KeyBindings
 from prompt_toolkit import prompt
 from prompt_toolkit import print_formatted_text as printf
-import enum
+import collections
 import math
 import time
 
-import lamb
+import lamb_engine
 
-from lamb.runner.misc import MacroDef
-from lamb.runner.misc import Command
-from lamb.runner.misc import StopReason
-from lamb.runner import commands as cmd
+from lamb_engine.runner.misc import MacroDef
+from lamb_engine.runner.misc import Command
+from lamb_engine.runner.misc import StopReason
+from lamb_engine.runner import commands as cmd
 
 
 # Keybindings for step prompt.
@@ -32,21 +32,21 @@ class Runner:
 		self.macro_table = {}
 		self.prompt_session = prompt_session
 		self.prompt_message = prompt_message
-		self.parser = lamb.parser.LambdaParser(
-			action_func = lamb.nodes.Func.from_parse,
-			action_bound = lamb.nodes.Macro.from_parse,
-			action_macro = lamb.nodes.Macro.from_parse,
-			action_call = lamb.nodes.Call.from_parse,
-			action_church = lamb.nodes.Church.from_parse,
+		self.parser = lamb_engine.parser.LambdaParser(
+			action_func = lamb_engine.nodes.Func.from_parse,
+			action_bound = lamb_engine.nodes.Macro.from_parse,
+			action_macro = lamb_engine.nodes.Macro.from_parse,
+			action_call = lamb_engine.nodes.Call.from_parse,
+			action_church = lamb_engine.nodes.Church.from_parse,
 			action_macro_def = MacroDef.from_parse,
 			action_command = Command.from_parse,
-			action_history = lamb.nodes.History.from_parse
+			action_history = lamb_engine.nodes.History.from_parse
 		)
 
 		# Maximum amount of reductions.
 		# If None, no maximum is enforced.
 		# Must be at least 1.
-		self.reduction_limit: int | None = 1_000_000
+		self.reduction_limit = 1_000_000
 
 		# Ensure bound variables are unique.
 		# This is automatically incremented whenever we make
@@ -58,7 +58,10 @@ class Runner:
 		# so that all digits appear to be changing.
 		self.iter_update = 231
 
-		self.history: list[lamb.nodes.Root] = []
+		self.history = collections.deque(
+			[None] * 10,
+			10)
+
 
 		# If true, reduce step-by-step.
 		self.step_reduction = False
@@ -71,23 +74,23 @@ class Runner:
 			message = self.prompt_message
 		)
 
-	def parse(self, line) -> tuple[lamb.nodes.Root | MacroDef | Command, list]:
+	def parse(self, line): # -> tuple[lamb_engine.nodes.Root | MacroDef | Command, list]
 		e = self.parser.parse_line(line)
 
 		w = []
 		if isinstance(e, MacroDef):
-			e.expr = lamb.nodes.Root(e.expr)
+			e.expr = lamb_engine.nodes.Root(e.expr)
 			e.set_runner(self)
-			w = lamb.nodes.prepare(e.expr, ban_macro_name = e.label)
-		elif isinstance(e, lamb.nodes.Node):
-			e = lamb.nodes.Root(e)
+			w = lamb_engine.nodes.prepare(e.expr, ban_macro_name = e.label)
+		elif isinstance(e, lamb_engine.nodes.Node):
+			e = lamb_engine.nodes.Root(e)
 			e.set_runner(self)
-			w = lamb.nodes.prepare(e)
+			w = lamb_engine.nodes.prepare(e)
 
 		return e, w
 
 
-	def reduce(self, node: lamb.nodes.Root, *, warnings = []) -> None:
+	def reduce(self, node: lamb_engine.nodes.Root, *, warnings = []) -> None:
 
 		# Reduction Counter.
 		# We also count macro (and church) expansions,
@@ -100,16 +103,16 @@ class Runner:
 		out_text = []
 
 		only_macro = (
-			isinstance(node.left, lamb.nodes.Macro) or
-			isinstance(node.left, lamb.nodes.Church)
+			isinstance(node.left, lamb_engine.nodes.Macro) or
+			isinstance(node.left, lamb_engine.nodes.Church)
 		)
 		if only_macro:
 			stop_reason = StopReason.SHOW_MACRO
-		m, node = lamb.nodes.expand(node, force_all = only_macro)
+		m, node = lamb_engine.nodes.expand(node, force_all = only_macro)
 		macro_expansions += m
 
 		if len(warnings) != 0:
-			printf(FormattedText(warnings), style = lamb.utils.style)
+			printf(FormattedText(warnings), style = lamb_engine.utils.style)
 
 		if self.step_reduction:
 			printf(FormattedText([
@@ -120,58 +123,59 @@ class Runner:
 				("class:muted", "Press "),
 				("class:cmd_key", "enter"),
 				("class:muted", " to step.\n"),
-			]), style = lamb.utils.style)
+			]), style = lamb_engine.utils.style)
 
 
 		skip_to_end = False
-		while (
-				(
-					(self.reduction_limit is None) or
-					(k < self.reduction_limit)
-				) and not only_macro
-			):
-
-			# Show reduction count
-			if (
-					( (k >= self.iter_update) and (k % self.iter_update == 0) )
-					and not (self.step_reduction and not skip_to_end)
+		try:
+			while (
+					(
+						(self.reduction_limit is None) or
+						(k < self.reduction_limit)
+					) and not only_macro
 				):
-				print(f" Reducing... {k:,}", end = "\r")
 
-			try:
-				red_type, node = lamb.nodes.reduce(node)
-			except KeyboardInterrupt:
-				stop_reason = StopReason.INTERRUPT
-				break
+				# Show reduction count
+				if (
+						( (k >= self.iter_update) and (k % self.iter_update == 0) )
+						and not (self.step_reduction and not skip_to_end)
+					):
+					print(f" Reducing... {k:,}", end = "\r")
 
-			# If we can't reduce this expression anymore,
-			# it's in beta-normal form.
-			if red_type == lamb.nodes.ReductionType.NOTHING:
-				stop_reason = StopReason.BETA_NORMAL
-				break
+				# Reduce
+				red_type, node = lamb_engine.nodes.reduce(node)
 
-			# Count reductions
-			k += 1
-			if red_type == lamb.nodes.ReductionType.FUNCTION_APPLY:
-				macro_expansions += 1
+				# If we can't reduce this expression anymore,
+				# it's in beta-normal form.
+				if red_type == lamb_engine.nodes.ReductionType.NOTHING:
+					stop_reason = StopReason.BETA_NORMAL
+					break
 
-			# Pause after step if necessary
-			if self.step_reduction and not skip_to_end:
-				try:
-					s = prompt(
-						message = FormattedText([
-							("class:muted", lamb.nodes.reduction_text[red_type]),
-							("class:muted", f":{k:03} "),
-							("class:text", str(node)),
-						]),
-						style = lamb.utils.style,
-						key_bindings = step_bindings
-					)
-				except KeyboardInterrupt or EOFError:
-					skip_to_end = True
-					printf(FormattedText([
-						("class:warn", "Skipping to end."),
-					]), style = lamb.utils.style)
+				# Count reductions
+				k += 1
+				if red_type == lamb_engine.nodes.ReductionType.FUNCTION_APPLY:
+					macro_expansions += 1
+
+				# Pause after step if necessary
+				if self.step_reduction and not skip_to_end:
+					try:
+						s = prompt(
+							message = FormattedText([
+								("class:prompt", lamb_engine.nodes.reduction_text[red_type]),
+								("class:prompt", f":{k:03} ")
+							] + lamb_engine.utils.lex_str(str(node))),
+							style = lamb_engine.utils.style,
+							key_bindings = step_bindings
+						)
+					except KeyboardInterrupt or EOFError:
+						skip_to_end = True
+						printf(FormattedText([
+							("class:warn", "Skipping to end."),
+						]), style = lamb_engine.utils.style)
+
+		# Gracefully catch keyboard interrupts
+		except KeyboardInterrupt:
+			stop_reason = StopReason.INTERRUPT
 
 		# Print a space between step messages
 		if self.step_reduction:
@@ -183,7 +187,7 @@ class Runner:
 
 		# Expand fully if necessary
 		if self.full_expansion:
-			o, node = lamb.nodes.expand(node, force_all = True)
+			o, node = lamb_engine.nodes.expand(node, force_all = True)
 			macro_expansions += o
 
 		if only_macro:
@@ -192,24 +196,31 @@ class Runner:
 			]
 
 		else:
+			if not self.step_reduction:
+				out_text += [
+					("class:ok", f"Runtime: "),
+					("class:text", f"{time.time() - start_time:.03f} seconds"),
+					("class:text", "\n")
+				]
+
 			out_text += [
-				("class:ok", f"Runtime: "),
-				("class:text", f"{time.time() - start_time:.03f} seconds"),
-
-				("class:ok", f"\nExit reason: "),
+				("class:ok", f"Exit reason: "),
 				stop_reason.value,
+				("class:text", "\n"),
 
-				("class:ok", f"\nMacro expansions: "),
+				("class:ok", f"Macro expansions: "),
 				("class:text", f"{macro_expansions:,}"),
+				("class:text", "\n"),
 
-				("class:ok", f"\nReductions: "),
+				("class:ok", f"Reductions: "),
 				("class:text", f"{k:,}\t"),
 				("class:muted", f"(Limit: {self.reduction_limit:,})")
 			]
 
 		if self.full_expansion:
 			out_text += [
-				("class:ok", "\nAll macros have been expanded")
+				("class:text", "\n"),
+				("class:ok", "All macros have been expanded")
 			]
 
 		if (
@@ -218,19 +229,23 @@ class Runner:
 				only_macro
 		):
 			out_text += [
-				("class:ok", "\n\n    => "),
-				("class:text", str(node)), # type: ignore
-			]
+				("class:ok", "\n\n    => ")
+			] + lamb_engine.utils.lex_str(str(node))
 
 
 		printf(
 			FormattedText(out_text),
-			style = lamb.utils.style
+			style = lamb_engine.utils.style
 		)
 
 		# Save to history
 		# Do this at the end so we don't always fully expand.
-		self.history.append(lamb.nodes.expand(node, force_all = True)[1])
+		self.history.appendleft(
+			lamb_engine.nodes.expand( # type: ignore
+				node,
+				force_all = True
+			)[1]
+		)
 
 	def save_macro(
 			self,
@@ -247,7 +262,7 @@ class Runner:
 				("class:code", macro.label),
 				("class:text", " to "),
 				("class:code", str(macro.expr))
-			]), style = lamb.utils.style)
+			]), style = lamb_engine.utils.style)
 
 	# Apply a list of definitions
 	def run(
@@ -269,13 +284,13 @@ class Runner:
 					FormattedText([
 						("class:warn", f"Unknown command \"{e.name}\"")
 					]),
-					style = lamb.utils.style
+					style = lamb_engine.utils.style
 				)
 			else:
 				cmd.commands[e.name](e, self)
 
 		# If this line is a plain expression, reduce it.
-		elif isinstance(e, lamb.nodes.Node):
+		elif isinstance(e, lamb_engine.nodes.Node):
 			self.reduce(e, warnings = w)
 
 		# We shouldn't ever get here.

lamb_engine/utils.py

@@ -4,6 +4,7 @@ from prompt_toolkit.lexers import Lexer
 from prompt_toolkit.key_binding import KeyBindings
 from prompt_toolkit import print_formatted_text as printf
 from importlib.metadata import version
+from prompt_toolkit.document import Document
 
 import re
 
@@ -77,6 +78,10 @@ class LambdaLexer(Lexer):
 		return inner
 
 
+
+def lex_str(s: str) -> list[tuple[str, str]]:
+	return LambdaLexer().lex_document(Document(s))(0)
+
 def show_greeting():
 	#   |  _.._ _.|_
 	#   |_(_|| | ||_)
@@ -96,7 +101,7 @@ def show_greeting():
 		"",
 		"<_h>    |  _.._ _.|_",
 		"    |_(_|| | ||_)</_h>",
-		f"        <_v>{version('lamb')}</_v>",
+		f"        <_v>{version('lamb_engine')}</_v>",
 		"        __  __",
 		"     ,-`  ``  `,",
 		"    (`   <_l>\\</_l>      )",

misc/demo.tape

@@ -0,0 +1,84 @@
+# See makedemo.sh
+
+#Output lambdemo.mp4
+Output lambdemo.gif
+
+Set FontSize 30
+Set Width 2000
+Set Height 1500
+Set FontFamily "FantasqueSansMono NF"
+Set TypingSpeed 60ms
+Set Framerate 30
+
+# Intro
+Sleep 2000ms
+Type "lamb"
+Sleep 1000ms
+Enter
+Sleep 2000ms
+
+# Demo 1: load
+Type ":load ../macros.lamb"
+Sleep 500ms
+Enter
+Sleep 2000ms
+
+Type "NOT T"
+Sleep 1000ms
+Enter
+Sleep 6s
+
+Type ":clear"
+Sleep 1000ms
+Enter
+Sleep 1500ms
+
+
+# Demo 2: stepping
+Type ":step"
+Sleep 500ms
+Enter
+Sleep 1500ms
+
+Type "NOT T"
+Sleep 100ms
+Enter
+Sleep 1500ms
+Enter
+Sleep 760ms
+Enter
+Sleep 850ms
+Enter
+Sleep 650ms
+Enter
+Sleep 700ms
+Enter
+
+Sleep 3000ms
+
+Type ":step"
+Sleep 500ms
+Enter
+Sleep 6s
+Type ":clear"
+Sleep 1000ms
+Enter
+Sleep 1500ms
+
+# Demo 3: macros
+Type "M = \x.x x"
+Sleep 500ms
+Enter
+Sleep 500ms
+
+Type "M M"
+Sleep 500ms
+Enter
+Sleep 3s
+Ctrl+c
+Sleep 1000ms
+
+Type "Y FAC 3"
+Sleep 500ms
+Enter
+Sleep 6s

misc/makedemo.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+# Should be run from the misc directory.
+# Will not work with any other root.
+
+# Create this file.
+# Should define two variables:
+# DAV_USER="name:password"
+# DAV_URL="https://site.com/dav-path"
+
+if [[ -f "secrets.sh" ]]; then
+	source secrets.sh
+else
+	echo "Cannot run without secrets.sh"
+	exit
+fi
+
+# Activate venv if not in venv
+if [[ "$VIRTUAL_ENV" == "" ]]; then
+	source ../venv/bin/activate
+fi
+
+# Make sure our venv is running the latest
+# version of lamb.
+pip install --editable ..
+
+
+# Make gif
+vhs < demo.tape
+
+# Upload
+curl \
+	--user $DAV_USER \
+	--url $DAV_URL \
+	--upload-file "lambdemo.gif"

pyproject.toml

@@ -1,30 +1,28 @@
+[build-system]
+requires = [ "setuptools>=61.0" ]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = [ "." ]
+include = ["lamb_engine*"]
+namespaces = false
+
+[project.scripts]
+lamb = "lamb_engine:main"
+
+
+
 [project]
-name = "Lamb"
+name = "lamb_engine"
 description = "A lambda calculus engine"
-
-# We use the standard semantic versioning:
-# maj.min.pat
-#
-# Major release:
-# 1.0.0 is the first stable release.
-# Incremented on BIG breaking changes.
-#
-# Minor release:
-# Large bug fixes, new features
-#
-# Patch release:
-# Small, compatible fixes.
-version = "0.1.3"
-
+version = "1.1.9"
 dependencies = [
 	"prompt-toolkit==3.0.31",
 	"pyparsing==3.0.9"
 ]
-
 authors = [
 	{ name="Mark", email="mark@betalupi.com" }
 ]
-
 readme = "README.md"
 requires-python = ">=3.7"
 license = {text = "GNU General Public License v3 (GPLv3)"}
@@ -35,20 +33,10 @@ classifiers = [
 	"Environment :: Console"
 ]
 
-
 [project.urls]
 "Homepage" = "https://git.betalupi.com/Mark/lamb"
 
-
-[build-system]
-requires = [ "setuptools>=61.0" ]
-build-backend = "setuptools.build_meta"
-
-[tool.setuptools.packages.find]
-where = ["lamb"]
-include = ["lamb*"]
-namespaces = false
-
-[project.optional-dependencies]
-# Used to build a standalone executable
-pyinstaller = [	"pyinstaller==5.5" ]
+# To build:
+# pip install build twine
+# python -m build
+# twine upload dist/lamb_engine-1.1.6* (change the version)