diff --git a/src/xoomonk.py b/src/xoomonk.py
index f3c06ed..2d51433 100755
--- a/src/xoomonk.py
+++ b/src/xoomonk.py
@@ -25,6 +25,269 @@
if self.value is None:
return 'AST(%r,%r)' % (self.type, self.children)
return 'AST(%r,value=%r)' % (self.type, self.value)
+
+
+class Scanner(object):
+ """A Scanner provides facilities for extracting successive
+ Xoomonk tokens from a string.
+
+ >>> a = Scanner(" {:= } foo ")
+ >>> a.token
+ '{'
+ >>> a.type
+ 'operator'
+ >>> a.scan()
+ >>> a.on(":=")
+ True
+ >>> a.on_type('operator')
+ True
+ >>> a.check_type('identifier')
+ Traceback (most recent call last):
+ ...
+ SyntaxError: Expected identifier, but found operator (':=')
+ >>> a.scan()
+ >>> a.consume(".")
+ False
+ >>> a.consume("}")
+ True
+ >>> a.expect("foo")
+ >>> a.type
+ 'EOF'
+ >>> a.expect("bar")
+ Traceback (most recent call last):
+ ...
+ SyntaxError: Expected 'bar', but found 'None'
+
+ """
+ def __init__(self, text):
+ self.text = text
+ self.token = None
+ self.type = None
+ self.scan()
+
+ def scan_pattern(self, pattern, type, token_group=1, rest_group=2):
+ pattern = r'^(' + pattern + r')(.*?)$'
+ match = re.match(pattern, self.text, re.DOTALL)
+ if not match:
+ return False
+ else:
+ self.type = type
+ self.token = match.group(token_group)
+ self.text = match.group(rest_group)
+ #print >>sys.stderr, "(%r/%s->%r)" % (self.token, self.type, self.text)
+ return True
+
+ def scan(self):
+ self.scan_pattern(r'[ \t\n\r]*', 'whitespace')
+ if not self.text:
+ self.token = None
+ self.type = 'EOF'
+ return
+ if self.scan_pattern(r':=|\;|\{|\}|\*|\.|\^|\$', 'operator'):
+ return
+ if self.scan_pattern(r'\d+', 'integer literal'):
+ return
+ if self.scan_pattern(r'\"(.*?)\"', 'string literal',
+ token_group=2, rest_group=3):
+ return
+ if self.scan_pattern(r'\w+', 'identifier'):
+ return
+ if self.scan_pattern(r'.', 'unknown character'):
+ return
+ else:
+ raise ValueError, "this should never happen, self.text=(%s)" % self.text
+
+ def expect(self, token):
+ if self.token == token:
+ self.scan()
+ else:
+ raise SyntaxError("Expected '%s', but found '%s'" %
+ (token, self.token))
+
+ def on(self, token):
+ return self.token == token
+
+ def on_type(self, type):
+ return self.type == type
+
+ def check_type(self, type):
+ if not self.type == type:
+ raise SyntaxError("Expected %s, but found %s ('%s')" %
+ (type, self.type, self.token))
+
+ def consume(self, token):
+ if self.token == token:
+ self.scan()
+ return True
+ else:
+ return False
+
+
+# Parser
+
+class Parser(object):
+ """A Parser provides facilities for recognizing various
+ parts of a Xoomonk program based on Xoomonk's grammar.
+
+ >>> a = Parser("123")
+ >>> a.expr()
+ AST('IntLit',value=123)
+ >>> a = Parser("{ a := 123 }")
+ >>> a.expr()
+ AST('Block',[AST('Assignment',[AST('Ref',[AST('Identifier',value='a')]), AST('IntLit',value=123)])])
+
+ >>> a = Parser("a:=5 c:=4")
+ >>> a.program()
+ AST('Program',[AST('Assignment',[AST('Ref',[AST('Identifier',value='a')]), AST('IntLit',value=5)]), AST('Assignment',[AST('Ref',[AST('Identifier',value='c')]), AST('IntLit',value=4)])])
+
+ >>> a = Parser("a := { b := 1 }")
+ >>> a.program()
+ AST('Program',[AST('Assignment',[AST('Ref',[AST('Identifier',value='a')]), AST('Block',[AST('Assignment',[AST('Ref',[AST('Identifier',value='b')]), AST('IntLit',value=1)])])])])
+
+ """
+ def __init__(self, text):
+ self.scanner = Scanner(text)
+
+ def program(self):
+ p = AST('Program')
+ while self.scanner.type != 'EOF':
+ p.add_child(self.stmt())
+ return p
+
+ def stmt(self):
+ if self.scanner.on("print"):
+ return self.print_stmt()
+ else:
+ return self.assign()
+
+ def assign(self):
+ r = self.ref()
+ self.scanner.expect(":=")
+ e = self.expr()
+ return AST('Assignment', [r, e])
+
+ def print_stmt(self):
+ s = None
+ self.scanner.expect("print")
+ if self.scanner.consume("string"):
+ self.scanner.check_type("string literal")
+ st = self.scanner.token
+ self.scanner.scan()
+ s = AST('PrintString', value=st)
+ elif self.scanner.consume("char"):
+ e = self.expr()
+ s = AST('PrintChar', [e])
+ else:
+ e = self.expr()
+ s = AST('Print', [e])
+ newline = True
+ if self.scanner.consume(";"):
+ newline = False
+ if newline:
+ s = AST('Newline', [s])
+ return s
+
+ def expr(self):
+ v = None
+ if self.scanner.on("{"):
+ v = self.block()
+ elif self.scanner.on_type('integer literal'):
+ v = AST('IntLit', value=int(self.scanner.token))
+ self.scanner.scan()
+ else:
+ v = self.ref()
+ if self.scanner.consume("*"):
+ v = AST('CopyOf', [v])
+ return v
+
+ def block(self):
+ b = AST('Block')
+ self.scanner.expect("{")
+ while not self.scanner.on("}"):
+ b.add_child(self.stmt())
+ self.scanner.expect("}")
+ return b
+
+ def ref(self):
+ r = AST('Ref')
+ r.add_child(self.name())
+ while self.scanner.consume("."):
+ r.add_child(self.name())
+ return r
+
+ def name(self):
+ if self.scanner.consume("^"):
+ return AST('Upvalue')
+ elif self.scanner.consume("$"):
+ self.scanner.check_type("identifier")
+ id = self.scanner.token
+ self.scanner.scan()
+ return AST('Dollar', value=id)
+ else:
+ self.scanner.check_type("identifier")
+ id = self.scanner.token
+ self.scanner.scan()
+ return AST('Identifier', value=id)
+
+
+# Runtime support for Xoomonk.
+
+def demo(store):
+ print "demo!"
+
+class MalingeringStore(object):
+ """
+ >>> a = MalingeringStore(['a','b'], [], demo)
+ demo!
+ >>> a['a'] = 7
+ >>> print a['a']
+ 7
+ >>> a['c'] = 7
+ Traceback (most recent call last):
+ ...
+ ValueError: Attempt to assign undefined variable c
+ >>> a = MalingeringStore(['a','b'], ['a'], demo)
+ >>> a['a'] = 7
+ demo!
+ >>> a = MalingeringStore(['a','b'], ['a'], demo)
+ >>> a['b'] = 7
+ Traceback (most recent call last):
+ ...
+ ValueError: Attempt to assign unresolved variable b
+
+ """
+ def __init__(self, variables, unassigned, fun):
+ self.dict = {}
+ self.variables = variables
+ for variable in self.variables:
+ self.dict[variable] = 0
+ self.unassigned = unassigned
+ self.fun = fun
+ if not self.unassigned:
+ self.run()
+
+ def run(self):
+ self.fun(self)
+
+ def __getitem__(self, name):
+ if name not in self.variables:
+ raise ValueError("Attempt to access undefined variable %s" % name)
+ # check to see if it is unassigned or derived
+ return self.dict[name]
+
+ def __setitem__(self, name, value):
+ if name not in self.variables:
+ raise ValueError("Attempt to assign undefined variable %s" % name)
+ if name in self.unassigned:
+ self.dict[name] = value
+ self.unassigned.remove(name)
+ if not self.unassigned:
+ self.run()
+ elif self.unassigned:
+ raise ValueError("Attempt to assign unresolved variable %s" % name)
+ else:
+ # the store is saturated, do what you want
+ self.dict[name] = value
def eval_xoomonk(ast, state):
@@ -64,269 +327,6 @@
raise NotImplementedError, "not an AST type I know: %s" % type
-class Scanner(object):
- """A Scanner provides facilities for extracting successive
- Xoomonk tokens from a string.
-
- >>> a = Scanner(" {:= } foo ")
- >>> a.token
- '{'
- >>> a.type
- 'operator'
- >>> a.scan()
- >>> a.on(":=")
- True
- >>> a.on_type('operator')
- True
- >>> a.check_type('identifier')
- Traceback (most recent call last):
- ...
- SyntaxError: Expected identifier, but found operator (':=')
- >>> a.scan()
- >>> a.consume(".")
- False
- >>> a.consume("}")
- True
- >>> a.expect("foo")
- >>> a.type
- 'EOF'
- >>> a.expect("bar")
- Traceback (most recent call last):
- ...
- SyntaxError: Expected 'bar', but found 'None'
-
- """
- def __init__(self, text):
- self.text = text
- self.token = None
- self.type = None
- self.scan()
-
- def scan_pattern(self, pattern, type, token_group=1, rest_group=2):
- pattern = r'^(' + pattern + r')(.*?)$'
- match = re.match(pattern, self.text, re.DOTALL)
- if not match:
- return False
- else:
- self.type = type
- self.token = match.group(token_group)
- self.text = match.group(rest_group)
- #print >>sys.stderr, "(%r/%s->%r)" % (self.token, self.type, self.text)
- return True
-
- def scan(self):
- self.scan_pattern(r'[ \t\n\r]*', 'whitespace')
- if not self.text:
- self.token = None
- self.type = 'EOF'
- return
- if self.scan_pattern(r':=|\;|\{|\}|\*|\.|\^|\$', 'operator'):
- return
- if self.scan_pattern(r'\d+', 'integer literal'):
- return
- if self.scan_pattern(r'\"(.*?)\"', 'string literal',
- token_group=2, rest_group=3):
- return
- if self.scan_pattern(r'\w+', 'identifier'):
- return
- if self.scan_pattern(r'.', 'unknown character'):
- return
- else:
- raise ValueError, "this should never happen, self.text=(%s)" % self.text
-
- def expect(self, token):
- if self.token == token:
- self.scan()
- else:
- raise SyntaxError("Expected '%s', but found '%s'" %
- (token, self.token))
-
- def on(self, token):
- return self.token == token
-
- def on_type(self, type):
- return self.type == type
-
- def check_type(self, type):
- if not self.type == type:
- raise SyntaxError("Expected %s, but found %s ('%s')" %
- (type, self.type, self.token))
-
- def consume(self, token):
- if self.token == token:
- self.scan()
- return True
- else:
- return False
-
-
-# Parser
-
-class Parser(object):
- """A Parser provides facilities for recognizing various
- parts of a Xoomonk program based on Xoomonk's grammar.
-
- >>> a = Parser("123")
- >>> a.expr()
- AST('IntLit',value=123)
- >>> a = Parser("{ a := 123 }")
- >>> a.expr()
- AST('Block',[AST('Assignment',[AST('Ref',[AST('Identifier',value='a')]), AST('IntLit',value=123)])])
-
- >>> a = Parser("a:=5 c:=4")
- >>> a.program()
- AST('Program',[AST('Assignment',[AST('Ref',[AST('Identifier',value='a')]), AST('IntLit',value=5)]), AST('Assignment',[AST('Ref',[AST('Identifier',value='c')]), AST('IntLit',value=4)])])
-
- >>> a = Parser("a := { b := 1 }")
- >>> a.program()
- AST('Program',[AST('Assignment',[AST('Ref',[AST('Identifier',value='a')]), AST('Block',[AST('Assignment',[AST('Ref',[AST('Identifier',value='b')]), AST('IntLit',value=1)])])])])
-
- """
- def __init__(self, text):
- self.scanner = Scanner(text)
-
- def program(self):
- p = AST('Program')
- while self.scanner.type != 'EOF':
- p.add_child(self.stmt())
- return p
-
- def stmt(self):
- if self.scanner.on("print"):
- return self.print_stmt()
- else:
- return self.assign()
-
- def assign(self):
- r = self.ref()
- self.scanner.expect(":=")
- e = self.expr()
- return AST('Assignment', [r, e])
-
- def print_stmt(self):
- s = None
- self.scanner.expect("print")
- if self.scanner.consume("string"):
- self.scanner.check_type("string literal")
- st = self.scanner.token
- self.scanner.scan()
- s = AST('PrintString', value=st)
- elif self.scanner.consume("char"):
- e = self.expr()
- s = AST('PrintChar', [e])
- else:
- e = self.expr()
- s = AST('Print', [e])
- newline = True
- if self.scanner.consume(";"):
- newline = False
- if newline:
- s = AST('Newline', [s])
- return s
-
- def expr(self):
- v = None
- if self.scanner.on("{"):
- v = self.block()
- elif self.scanner.on_type('integer literal'):
- v = AST('IntLit', value=int(self.scanner.token))
- self.scanner.scan()
- else:
- v = self.ref()
- if self.scanner.consume("*"):
- v = AST('CopyOf', [v])
- return v
-
- def block(self):
- b = AST('Block')
- self.scanner.expect("{")
- while not self.scanner.on("}"):
- b.add_child(self.stmt())
- self.scanner.expect("}")
- return b
-
- def ref(self):
- r = AST('Ref')
- r.add_child(self.name())
- while self.scanner.consume("."):
- r.add_child(self.name())
- return r
-
- def name(self):
- if self.scanner.consume("^"):
- return AST('Upvalue')
- elif self.scanner.consume("$"):
- self.scanner.check_type("identifier")
- id = self.scanner.token
- self.scanner.scan()
- return AST('Dollar', value=id)
- else:
- self.scanner.check_type("identifier")
- id = self.scanner.token
- self.scanner.scan()
- return AST('Identifier', value=id)
-
-
-# Runtime support for Xoomonk.
-
-def demo(store):
- print "demo!"
-
-class MalingeringStore(object):
- """
- >>> a = MalingeringStore(['a','b'], [], demo)
- demo!
- >>> a['a'] = 7
- >>> print a['a']
- 7
- >>> a['c'] = 7
- Traceback (most recent call last):
- ...
- ValueError: Attempt to assign undefined variable c
- >>> a = MalingeringStore(['a','b'], ['a'], demo)
- >>> a['a'] = 7
- demo!
- >>> a = MalingeringStore(['a','b'], ['a'], demo)
- >>> a['b'] = 7
- Traceback (most recent call last):
- ...
- ValueError: Attempt to assign unresolved variable b
-
- """
- def __init__(self, variables, unassigned, fun):
- self.dict = {}
- self.variables = variables
- for variable in self.variables:
- self.dict[variable] = 0
- self.unassigned = unassigned
- self.fun = fun
- if not self.unassigned:
- self.run()
-
- def run(self):
- self.fun(self)
-
- def __getitem__(self, name):
- if name not in self.variables:
- raise ValueError("Attempt to access undefined variable %s" % name)
- # check to see if it is unassigned or derived
- return self.dict[name]
-
- def __setitem__(self, name, value):
- if name not in self.variables:
- raise ValueError("Attempt to assign undefined variable %s" % name)
- if name in self.unassigned:
- self.dict[name] = value
- self.unassigned.remove(name)
- if not self.unassigned:
- self.run()
- elif self.unassigned:
- raise ValueError("Attempt to assign unresolved variable %s" % name)
- else:
- # the store is saturated, do what you want
- self.dict[name] = value
-
-
def main(argv):
optparser = OptionParser(__doc__)
optparser.add_option("-a", "--show-ast",