convert lexer and parser into classes

parser/Lexer.py

@@ -0,0 +1,76 @@
+
+import ply.lex as lex
+
+class Lexer(object):
+    def __init__(self):
+        self.reserved = {
+                'C': 'C',
+                }
+
+        self.tokens = [
+                'LPAREN',
+                'RPAREN',
+                'SEMICOLON',
+                'STRING',
+                'ID',
+                ] + list(self.reserved.values())
+
+        self.states = (
+                ('string', 'exclusive'),
+                )
+
+        self.t_LPAREN = r'\('
+        self.t_RPAREN = r'\)'
+        self.t_SEMICOLON = r';'
+
+        self.t_ignore = ' \t\r'
+
+        self.lexer = lex.lex(module = self)
+
+    def t_ID(self, t):
+        r'[a-zA-Z_][a-zA-Z_0-9]*'
+        t.type = self.reserved.get(t.value, 'ID')
+        return t
+
+    def t_STRING(self, t):
+        r'\"'
+        self.str_buildup = ''
+        t.lexer.begin('string')
+
+    def t_string_1(self, t):
+        r'[^\\\n\"]'
+        self.str_buildup += t.value
+
+    def t_string_2(self, t):
+        r'\\[^\n]'
+        c = {
+                't': '\t',
+                'r': '\r',
+                'n': '\n',
+                'f': '\f',
+                'b': '\b',
+                'v': '\v',
+            }.get(t.value[1], t.value[1])
+        self.str_buildup += c
+
+    def t_string_3(self, t):
+        r'\"'
+        t.type = 'STRING'
+        t.value = self.str_buildup
+        t.lexer.begin('INITIAL')
+        return t
+
+    def t_newline(self, t):
+        r'\n+'
+        t.lexer.lineno += len(t.value)
+        return None
+
+    def t_error(self, t):
+        print 'Illegal character "%s"' % t.value[0]
+        t.lexer.skip(1)
+
+    def input(self, *args):
+        self.lexer.input(*args)
+
+    def token(self, *args):
+        return self.lexer.token(*args)

parser/Parser.py

@@ -0,0 +1,46 @@
+
+import ply.yacc as yacc
+from Lexer import Lexer
+from nodes import *
+
+class Parser(object):
+    def __init__(self, input):
+        self.input = input
+        self.lexer = Lexer()
+        self.tokens = self.lexer.tokens
+        self.parser = yacc.yacc(module = self, outputdir = 'parser')
+
+    def p_unit(self, p):
+        'unit : unit_items'
+        p[0] = UnitNode([p[1]])
+
+    def p_unit_items(self, p):
+        'unit_items : unit_item unit_items'
+        p[0] = Node([p[1]] + p[2].children)
+
+    def p_unit_items_empty(self, p):
+        'unit_items : empty'
+        p[0] = p[1]
+
+    def p_unit_item_c_stmt(self, p):
+        'unit_item : c_expr SEMICOLON'
+        p[0] = p[1]
+
+    def p_statement(self, p):
+        'statement : expr SEMICOLON'
+        p[0] = StatementNode([p[1]])
+
+    def p_expr(self, p):
+        'expr : c_expr'
+        p[0] = p[1]
+
+    def p_c_expr(self, p):
+        'c_expr : C LPAREN STRING RPAREN'
+        p[0] = CExprNode(p[3])
+
+    def p_empty(self, p):
+        'empty :'
+        p[0] = Node()
+
+    def parse(self):
+        return self.parser.parse(self.input, lexer = self.lexer)

parser/__init__.py

@@ -1,11 +1,5 @@
 
-import ply.lex as lex
-import ply.yacc as yacc
-import lexrules
-import parserules
+from Parser import Parser
 
 def parse(input):
-    lexer = lex.lex(module = lexrules)
-    parser = yacc.yacc(module = parserules, outputdir = 'parser')
-    result = parser.parse(input)
-    return result
+    return Parser(input).parse()

parser/lexrules.py

@@ -1,64 +0,0 @@
-
-reserved = {
-        'C': 'C',
-        }
-
-tokens = [
-        'LPAREN',
-        'RPAREN',
-        'SEMICOLON',
-        'STRING',
-        'ID',
-        ] + list(reserved.values())
-
-states = (
-        ('string', 'exclusive'),
-        )
-
-t_LPAREN = r'\('
-t_RPAREN = r'\)'
-t_SEMICOLON = r';'
-
-t_ignore = ' \t\r'
-
-def t_ID(t):
-    r'[a-zA-Z_][a-zA-Z_0-9]*'
-    t.type = reserved.get(t.value, 'ID')
-    return t
-
-def t_STRING(t):
-    r'\"'
-    t.lexer.str_buildup = ''
-    t.lexer.begin('string')
-
-def t_string_1(t):
-    r'[^\\\n\"]'
-    t.lexer.str_buildup += t.value
-
-def t_string_2(t):
-    r'\\[^\n]'
-    c = {
-            't': '\t',
-            'r': '\r',
-            'n': '\n',
-            'f': '\f',
-            'b': '\b',
-            'v': '\v',
-        }.get(t.value[1], t.value[1])
-    t.lexer.str_buildup += c
-
-def t_string_3(t):
-    r'\"'
-    t.type = 'STRING'
-    t.value = t.lexer.str_buildup
-    t.lexer.begin('INITIAL')
-    return t
-
-def t_newline(t):
-    r'\n+'
-    t.lexer.lineno += len(t.value)
-    return None
-
-def t_error(t):
-    print 'Illegal character "%s"' % t.value[0]
-    t.lexer.skip(1)

parser/parserules.py

@@ -1,35 +0,0 @@
-
-from lexrules import tokens
-from nodes import *
-
-def p_unit(p):
-    'unit : unit_items'
-    p[0] = UnitNode([p[1]])
-
-def p_unit_items(p):
-    'unit_items : unit_item unit_items'
-    p[0] = Node([p[1]] + p[2].children)
-
-def p_unit_items_empty(p):
-    'unit_items : empty'
-    p[0] = p[1]
-
-def p_unit_item_c_stmt(p):
-    'unit_item : c_expr SEMICOLON'
-    p[0] = p[1]
-
-def p_statement(p):
-    'statement : expr SEMICOLON'
-    p[0] = StatementNode([p[1]])
-
-def p_expr(p):
-    'expr : c_expr'
-    p[0] = p[1]
-
-def p_c_expr(p):
-    'c_expr : C LPAREN STRING RPAREN'
-    p[0] = CExprNode(p[3])
-
-def p_empty(p):
-    'empty :'
-    p[0] = Node()