let's get more serious (splat that mess)

.gitignore

@@ -0,0 +1 @@
+*.pyc

parser.py

@@ -1,96 +0,0 @@
-from __future__ import print_function
-from rply import ParserGenerator, LexerGenerator
-from rply.token import BaseBox
-
-lg = LexerGenerator()
-lg.add("LPAREN", r"\(")
-lg.add("RPAREN", r"\)")
-lg.add("QUOTE", r"'")
-lg.add("ATOM", r"[^\s()]+")
-lg.ignore(r"\s+")
-
-pg = ParserGenerator(["QUOTE", "LPAREN", "RPAREN", "ATOM"])
-
-
-@pg.error
-def error_handler(token):
-    type = token.gettokentype()
-    pos = token.getsourcepos()
-    raise ValueError("unexpected %s at (%s, %s)" %
-                     (type, pos.lineno, pos.colno))
-
-
-@pg.production("main : sexpr")
-def main(p):
-    return p[0]
-
-
-@pg.production("sexpr : ATOM")
-@pg.production("sexpr : QUOTE sexpr")
-@pg.production("sexpr : LPAREN list RPAREN")
-def sexpr(p):
-    if p[0].gettokentype() == "ATOM":
-        return BoxAtom(p[0].getstr())
-    elif p[0].gettokentype() == "QUOTE":
-        return BoxQuote(p[1])
-    else:
-        return p[1]
-
-
-@pg.production("list : sexpr")
-@pg.production("list : sexpr list")
-def list(p):
-    if len(p) == 1:
-        return BoxPair(p[0])
-    else:
-        return BoxPair(p[0], p[1])
-
-lexer = lg.build()
-parser = pg.build()
-
-
-class BoxQuote(BaseBox):
-    def __init__(self, sexpr):
-        self.sexpr = sexpr
-
-    def sexpr(self):
-        return self.sexpr
-
-    def __str__(self):
-        return "' %s" % self.sexpr
-
-
-class BoxPair(BaseBox):
-    def __init__(self, x, y=None):
-        self.x = x
-        self.y = y
-
-    def __str__(self):
-        if self.y is None:
-            y = "NIL"
-        else:
-            y = self.y
-        return "(%s . %s)" % (self.x, y)
-
-
-class BoxAtom(BaseBox):
-    def __init__(self, atom):
-        self.atom = atom
-
-    def atom(self):
-        return self.atom
-
-    def __str__(self):
-        return "%s" % (self.atom)
-
-
-print(parser.parse(lexer.lex("1")))
-print(parser.parse(lexer.lex("'1")))
-print(parser.parse(lexer.lex("+")))
-print(parser.parse(lexer.lex("'+")))
-print(parser.parse(lexer.lex("(+ 1 2)")))
-print(parser.parse(lexer.lex("'(+ 1 2)")))
-print(parser.parse(lexer.lex("(+ 1 (* 3 2))")))
-print(parser.parse(lexer.lex("'(+ 1 (* 3 2))")))
-print(parser.parse(lexer.lex("(+ (* 4 5) (* 3 2))")))
-print(parser.parse(lexer.lex("(+ '(* 4 5) (* 3 2))")))

requirements.txt

@@ -0,0 +1 @@
+rply==0.6.1

test.py

@@ -0,0 +1,39 @@
+from unittest import TestCase
+import wasp.parser as parser
+
+class TestParser(TestCase):
+    def test_atom(self):
+        self.assertEqual(str(parser.parse("1")), "1")
+
+    def test_quoted_atom(self):
+        self.assertEqual(str(parser.parse("'1")), "'1")
+
+    def test_nonalpha_symbol(self):
+        self.assertEqual(str(parser.parse("+")), "+")
+
+    def test_quoted_nonalpha_symbol(self):
+        self.assertEqual(str(parser.parse("'+")), "'+")
+
+    def test_list(self):
+        self.assertEqual(str(parser.parse("(+ 1 2)")),
+                         "(+ . (1 . (2 . NIL)))")
+
+    def test_quoted_list(self):
+        self.assertEqual(str(parser.parse("'(+ 1 2)")),
+                         "'(+ . (1 . (2 . NIL)))")
+
+    def test_list_in_list(self):
+        self.assertEqual(str(parser.parse("(+ 1 (* 3 2))")),
+                         "(+ . (1 . ((* . (3 . (2 . NIL))) . NIL)))")
+
+    def test_lists_in_list(self):
+        self.assertEqual(str(parser.parse("(+ (* 4 5) (* 3 2))")),
+                         "(+ . ((* . (4 . (5 . NIL))) . ((* . (3 . (2 . NIL))) . NIL)))")
+
+    def test_quote_in_list(self):
+        self.assertEqual(str(parser.parse("(+ '1 (* 3 2))")),
+                         "(+ . ('1 . ((* . (3 . (2 . NIL))) . NIL)))")
+
+if __name__ == '__main__':
+    import unittest
+    unittest.main()

wasp/parser/__init__.py

@@ -0,0 +1,54 @@
+from rply import ParserGenerator, LexerGenerator
+import box
+
+
+lg = LexerGenerator()
+lg.add("LPAREN", r"\(")
+lg.add("RPAREN", r"\)")
+lg.add("QUOTE", r"'")
+lg.add("ATOM", r"[^\s()]+")
+lg.ignore(r"\s+")
+
+pg = ParserGenerator(["QUOTE", "LPAREN", "RPAREN", "ATOM"],
+                     precedence=[],
+                     cache_id="wasp")
+
+
+@pg.error
+def error_handler(token):
+    type = token.gettokentype()
+    pos = token.getsourcepos()
+    raise ValueError("unexpected %s at (%s, %s)" %
+                     (type, pos.lineno, pos.colno))
+
+
+@pg.production("main : sexpr")
+def main(p):
+    return p[0]
+
+
+@pg.production("sexpr : ATOM")
+@pg.production("sexpr : QUOTE sexpr")
+@pg.production("sexpr : LPAREN list RPAREN")
+def sexpr(p):
+    if p[0].gettokentype() == "ATOM":
+        return box.Atom(p[0].getstr())
+    elif p[0].gettokentype() == "QUOTE":
+        return box.Quote(p[1])
+    else:
+        return p[1]
+
+
+@pg.production("list : sexpr")
+@pg.production("list : sexpr list")
+def list(p):
+    if len(p) == 1:
+        return box.Pair(p[0])
+    else:
+        return box.Pair(p[0], p[1])
+
+lexer = lg.build()
+parser = pg.build()
+
+def parse(string):
+    return parser.parse(lexer.lex(string))

wasp/parser/box.py

@@ -0,0 +1,37 @@
+from rply.token import BaseBox
+
+class Quote(BaseBox):
+    def __init__(self, sexpr):
+        self.sexpr = sexpr
+
+    def sexpr(self):
+        return self.sexpr
+
+    def __str__(self):
+        return "'%s" % self.sexpr
+
+
+class Pair(BaseBox):
+    def __init__(self, x, y=None):
+        self.x = x
+        self.y = y
+
+    def __str__(self):
+        if self.y is None:
+            y = "NIL"
+        else:
+            y = self.y
+        return "(%s . %s)" % (self.x, y)
+
+
+class Atom(BaseBox):
+    def __init__(self, atom):
+        self.atom = atom
+
+    def atom(self):
+        return self.atom
+
+    def __str__(self):
+        return "%s" % (self.atom)
+
+