Cleanup & build files

lamb/parser.py

@@ -0,0 +1,79 @@
+import pyparsing as pp
+
+import lamb.tokens as tokens
+import lamb.utils as utils
+
+class Parser:
+	lp = pp.Suppress("(")
+	rp = pp.Suppress(")")
+
+	# Simple tokens
+	pp_expr = pp.Forward()
+	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.
+	#
+	# <var> => <exp>
+	pp_lambda_fun = (
+		(pp.Suppress("λ") | pp.Suppress("\\")) +
+		pp.Group(pp.Char(pp.alphas)[1, ...]) +
+		pp.Suppress(".") +
+		(pp_expr ^ pp_call)
+	)
+	pp_lambda_fun.set_parse_action(tokens.lambda_func.from_parse)
+
+	# Assignment.
+	# Can only be found at the start of a line.
+	#
+	# <name> = <exp>
+	pp_macro_def = (
+		pp.line_start() +
+		pp_macro +
+		pp.Suppress("=") +
+		(pp_expr ^ pp_call)
+	)
+	pp_macro_def.set_parse_action(tokens.macro_expression.from_parse)
+
+	pp_expr <<= (
+		pp_church ^
+		pp_lambda_fun ^
+		pp_macro ^
+		(lp + pp_expr + rp) ^
+		(lp + pp_call + rp)
+	)
+
+	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):
+		return Parser.pp_all.parse_string(
+			line,
+			parse_all = True
+		)[0]
+
+	@staticmethod
+	def run_tests(lines):
+		return Parser.pp_all.run_tests(lines)