.vscode/settings.json

@@ -1,9 +1,7 @@
 {
     "cSpell.words": [
-        "autochurch",
         "freevar",
         "pyparsing",
-        "runstatus",
         "subvar"
     ],
     "python.analysis.typeCheckingMode": "basic"

README.md

@@ -2,12 +2,15 @@
 
 
 ## Todo (pre-release):
+ - Fix parser (call parentheses)
  - Good command parsing (`:save`, `:load`, are a bare minimum)
  - Python files: installable, package list, etc
  - $\alpha$-equivalence check
  - Versioning
+ - Automatic church numerals
  - Prettyprint functions (combine args, rename bound variables)
  - Documentation in README
+ - Don't crash on errors
 
 ## Todo:
  - live syntax check
@@ -17,8 +20,6 @@
  - Warn when overwriting macro
  - Syntax highlighting: parenthesis, bound variables, macros, etc
  - Pin header to top of screen
- - Parser is a bit slow. Maybe we can do better?
 
 ## Mention in Docs
- - lambda functions only work with single-letter arguments
+ - lambda functions only work with single-letter arguments
- - church numerals

main.py

@@ -43,7 +43,7 @@ r.run_lines([
 	"OR = λab.(a T b)",
 	"XOR = λab.(a (NOT a b) b)",
 	"w = λx.(x x)",
-	"W = w w",
+	"W = (w w)",
 	"Y = λf.( (λx.(f (x x))) (λx.(f (x x))) )",
 	"PAIR = λabi.( i a b )",
 	"inc = λnfa.(f (n f a))",
@@ -90,13 +90,7 @@ while True:
 
 	# If this line defined a macro, print nothing.
 	if isinstance(x, runner.MacroStatus):
-		printf(FormattedText([
+		pass
-			("#FFFFFF", "Set "),
-			("#FF00FF", x.macro_label),
-			("#FFFFFF", " to "),
-			("#FFFFFF", str(x.macro_expr))
-		]))
-
 
 	if isinstance(x, runner.CommandStatus):
 		printf(x.formatted_text)

parser.py

@@ -1,8 +1,17 @@
 import pyparsing as pp
 import tokens
-import utils
 
 class Parser:
+	"""
+	Macro_def must be on its own line.
+	macro_def  :: var = expr
+
+	var        :: word
+	lambda_fun :: var -> expr
+	call       :: '(' (var | expr) ')' +
+	expr       :: define | var | call | '(' expr ')'
+	"""
+
 	lp = pp.Suppress("(")
 	rp = pp.Suppress(")")
 
@@ -11,18 +20,6 @@ class Parser:
 	pp_macro = pp.Word(pp.alphas + "_")
 	pp_macro.set_parse_action(tokens.macro.from_parse)
 
-	pp_church = pp.Word(pp.nums)
-	pp_church.set_parse_action(utils.autochurch)
-
-	# Function calls.
-	# `tokens.lambda_apply.from_parse` handles chained calls.
-	#
-	# <exp> <exp>
-	# <exp> <exp> <exp>
-	pp_call = pp.Forward()
-	pp_call <<= pp_expr[2, ...]
-	pp_call.set_parse_action(tokens.lambda_apply.from_parse)
-
 	# Function definitions.
 	# Right associative.
 	#
@@ -31,44 +28,41 @@ class Parser:
 		(pp.Suppress("λ") | pp.Suppress("\\")) +
 		pp.Group(pp.Char(pp.alphas)[1, ...]) +
 		pp.Suppress(".") +
-		(pp_expr ^ pp_call)
+		pp_expr
 	)
 	pp_lambda_fun.set_parse_action(tokens.lambda_func.from_parse)
 
 	# Assignment.
 	# Can only be found at the start of a line.
 	#
-	# <name> = <exp>
+	# <var> = <exp>
-	pp_macro_def = (
+	pp_macro_def = pp.line_start() + pp_macro + pp.Suppress("=") + pp_expr
-		pp.line_start() +
-		pp_macro +
-		pp.Suppress("=") +
-		(pp_expr ^ pp_call)
-	)
 	pp_macro_def.set_parse_action(tokens.macro_expression.from_parse)
 
-	pp_expr <<= (
+	# Function calls.
-		pp_church ^
+	# `tokens.lambda_func.from_parse` handles chained calls.
-		pp_lambda_fun ^
+	#
-		pp_macro ^
+	# <var>(<exp>)
-		(lp + pp_expr + rp) ^
+	# <var>(<exp>)(<exp>)(<exp>)
-		(lp + pp_call + rp)
+	# (<exp>)(<exp>)
-	)
+	# (<exp>)(<exp>)(<exp>)(<exp>)
+	pp_call = pp.Forward()
+	pp_call <<= pp_expr[2, ...]
+	pp_call.set_parse_action(tokens.lambda_apply.from_parse)
+
+	pp_expr <<= pp_lambda_fun ^ (lp + pp_expr + rp) ^ pp_macro ^ (lp + pp_call + rp)
+	pp_all = pp_expr | pp_macro_def
 
 	pp_command = pp.Suppress(":") + pp.Word(pp.alphas + "_")
 	pp_command.set_parse_action(tokens.command.from_parse)
 
-
-	pp_all = (
-		pp_expr ^
-		pp_macro_def ^
-		pp_command ^
-		pp_call
-	)
-
 	@staticmethod
 	def parse_line(line):
-		k = Parser.pp_all.parse_string(
+		k = (
+			Parser.pp_expr ^
+			Parser.pp_macro_def ^
+			Parser.pp_command ^ Parser.pp_call
+		).parse_string(
 			line,
 			parse_all = True
 		)[0]
@@ -77,4 +71,4 @@ class Parser:
 
 	@staticmethod
 	def run_tests(lines):
-		return Parser.pp_all.run_tests(lines)
+		return Parser.pp_macro_def.run_tests(lines)

runner.py

@@ -10,6 +10,10 @@ from runstatus import ReduceStatus
 from runstatus import CommandStatus
 
 
+
+
+
+
 class Runner:
 	def __init__(self):
 		self.macro_table = {}
@@ -39,7 +43,7 @@ class Runner:
 		i = 0
 		macro_expansions = 0
 
-		while (self.reduction_limit is None) or (i < self.reduction_limit):
+		while i < self.reduction_limit:
 			r = expr.reduce(self.macro_table)
 			expr = r.output
 
@@ -60,7 +64,7 @@ class Runner:
 		return ReduceStatus(
 			reduction_count = i - macro_expansions,
 			stop_reason = StopReason.MAX_EXCEEDED,
-			result = r.output  # type: ignore
+			result = r.output
 		)
 
 
@@ -77,8 +81,7 @@ class Runner:
 
 			return MacroStatus(
 				was_rewritten = was_rewritten,
-				macro_label = e.label,
+				macro_label = e.label
-				macro_expr = e.exp
 			)
 
 		# If this line is a command, do the command.
@@ -86,11 +89,9 @@ class Runner:
 			return self.exec_command(e.name)
 
 		# If this line is a plain expression, reduce it.
-		elif isinstance(e, tokens.LambdaToken):
+		else:
 			e.bind_variables()
 			return self.reduce_expression(e)
-		else:
-			raise TypeError(f"I don't know what to do with a {type(e)}")
 
 
 	def run_lines(self, lines: list[str]):

runstatus.py

@@ -17,19 +17,16 @@ class MacroStatus(RunStatus):
 	Values:
 	`was_rewritten`:	If true, an old macro was replaced.
 	`macro_label`:		The name of the macro we just made.
-	`macro_expr`:		The expr of the macro we just made.
 	"""
 
 	def __init__(
 		self,
 		*,
 		was_rewritten: bool,
-		macro_label: str,
+		macro_label: str
-		macro_expr
 	):
 		self.was_rewritten = was_rewritten
 		self.macro_label = macro_label
-		self.macro_expr = macro_expr
 
 
 class StopReason(enum.Enum):

tokens.py

@@ -302,9 +302,9 @@ class lambda_func(LambdaToken):
 
 
 		# Bind variables inside this function.
-		if isinstance(self.output, macro) and placeholder is not None:
+		if isinstance(self.output, macro):
 			if self.output == placeholder:
-				self.output = val # type: ignore
+				self.output = val
 		elif isinstance(self.output, lambda_func):
 			self.output.bind_variables(placeholder, val)
 		elif isinstance(self.output, lambda_apply):
@@ -345,7 +345,7 @@ class lambda_func(LambdaToken):
 		calling_self = False
 		if bound_var is None:
 			calling_self = True
-			bound_var = self.input # type: ignore
+			bound_var = self.input
 		new_out = self.output
 		if isinstance(self.output, bound_variable):
 			if self.output == bound_var:
@@ -353,7 +353,7 @@ class lambda_func(LambdaToken):
 		elif isinstance(self.output, lambda_func):
 			new_out = self.output.apply(val, bound_var = bound_var)
 		elif isinstance(self.output, lambda_apply):
-			new_out = self.output.sub_bound_var(val, bound_var = bound_var) # type: ignore
+			new_out = self.output.sub_bound_var(val, bound_var = bound_var)
 
 		# If we're applying THIS function,
 		# just give the output
@@ -430,7 +430,7 @@ class lambda_apply(LambdaToken):
 		# everything below should still work as expected.
 		if isinstance(self.fn, macro) and placeholder is not None:
 			if self.fn == placeholder:
-				self.fn = val # type: ignore
+				self.fn = val
 		elif isinstance(self.fn, lambda_func):
 			self.fn.bind_variables(placeholder, val)
 		elif isinstance(self.fn, lambda_apply):
@@ -438,7 +438,7 @@ class lambda_apply(LambdaToken):
 
 		if isinstance(self.arg, macro) and placeholder is not None:
 			if self.arg == placeholder:
-				self.arg = val # type: ignore
+				self.arg = val
 		elif isinstance(self.arg, lambda_func):
 			self.arg.bind_variables(placeholder, val)
 		elif isinstance(self.arg, lambda_apply):

utils.py

@@ -1,24 +0,0 @@
-import tokens
-
-def autochurch(results):
-	"""
-	Makes a church numeral from an integer.
-	"""
-
-	num = int(results[0])
-
-	f = tokens.bound_variable()
-	a = tokens.bound_variable()
-
-	chain = a
-
-	for i in range(num):
-		chain = tokens.lambda_apply(f, chain)
-
-	return tokens.lambda_func(
-		f,
-		tokens.lambda_func(
-			a,
-			chain
-		)
-	)