diff options
Diffstat (limited to 'trunk/src/examples/oc.py')
| -rw-r--r-- | trunk/src/examples/oc.py | 193 |
1 files changed, 0 insertions, 193 deletions
diff --git a/trunk/src/examples/oc.py b/trunk/src/examples/oc.py deleted file mode 100644 index 77ea195..0000000 --- a/trunk/src/examples/oc.py +++ /dev/null @@ -1,193 +0,0 @@ -# oc.py
-#
-# A subset-C parser, (BNF taken from 1996 International Obfuscated C Code Contest)
-#
-# Copyright, 2010, Paul McGuire
-#
-"""
-http://www.ioccc.org/1996/august.hint
-
-The following is a description of the OC grammar:
-
- OC grammar
- ==========
- Terminals are in quotes, () is used for bracketing.
-
- program: decl*
-
- decl: vardecl
- fundecl
-
- vardecl: type NAME ;
- type NAME "[" INT "]" ;
-
- fundecl: type NAME "(" args ")" "{" body "}"
-
- args: /*empty*/
- ( arg "," )* arg
-
- arg: type NAME
-
- body: vardecl* stmt*
-
- stmt: ifstmt
- whilestmt
- dowhilestmt
- "return" expr ";"
- expr ";"
- "{" stmt* "}"
- ";"
-
- ifstmt: "if" "(" expr ")" stmt
- "if" "(" expr ")" stmt "else" stmt
-
- whilestmt: "while" "(" expr ")" stmt
-
- dowhilestmt: "do" stmt "while" "(" expr ")" ";"
-
- expr: expr binop expr
- unop expr
- expr "[" expr "]"
- "(" expr ")"
- expr "(" exprs ")"
- NAME
- INT
- CHAR
- STRING
-
- exprs: /*empty*/
- (expr ",")* expr
-
- binop: "+" | "-" | "*" | "/" | "%" |
- "=" |
- "<" | "==" | "!="
-
- unop: "!" | "-" | "*"
-
- type: "int" stars
- "char" stars
-
- stars: "*"*
-"""
-
-from pyparsing import *
-
-LPAR,RPAR,LBRACK,RBRACK,LBRACE,RBRACE,SEMI,COMMA = map(Suppress, "()[]{};,")
-INT = Keyword("int")
-CHAR = Keyword("char")
-WHILE = Keyword("while")
-DO = Keyword("do")
-IF = Keyword("if")
-ELSE = Keyword("else")
-RETURN = Keyword("return")
-
-NAME = Word(alphas+"_", alphanums+"_")
-integer = Regex(r"[+-]?\d+")
-char = Regex(r"'.'")
-string_ = dblQuotedString
-
-INT = Keyword("int")
-CHAR = Keyword("char")
-TYPE = Group((INT | CHAR) + ZeroOrMore("*"))
-
-expr = Forward()
-operand = NAME | integer | char | string_
-expr << (infixNotation(operand,
- [
- (oneOf('! - *'), 1, opAssoc.RIGHT),
- (oneOf('++ --'), 1, opAssoc.RIGHT),
- (oneOf('++ --'), 1, opAssoc.LEFT),
- (oneOf('* / %'), 2, opAssoc.LEFT),
- (oneOf('+ -'), 2, opAssoc.LEFT),
- (oneOf('< == > <= >= !='), 2, opAssoc.LEFT),
- (Regex(r'=[^=]'), 2, opAssoc.LEFT),
- ]) +
- Optional( LBRACK + expr + RBRACK |
- LPAR + Group(Optional(delimitedList(expr))) + RPAR )
- )
-
-stmt = Forward()
-
-ifstmt = IF - LPAR + expr + RPAR + stmt + Optional(ELSE + stmt)
-whilestmt = WHILE - LPAR + expr + RPAR + stmt
-dowhilestmt = DO - stmt + WHILE + LPAR + expr + RPAR + SEMI
-returnstmt = RETURN - expr + SEMI
-
-stmt << Group( ifstmt |
- whilestmt |
- dowhilestmt |
- returnstmt |
- expr + SEMI |
- LBRACE + ZeroOrMore(stmt) + RBRACE |
- SEMI)
-
-vardecl = Group(TYPE + NAME + Optional(LBRACK + integer + RBRACK)) + SEMI
-
-arg = Group(TYPE + NAME)
-body = ZeroOrMore(vardecl) + ZeroOrMore(stmt)
-fundecl = Group(TYPE + NAME + LPAR + Optional(Group(delimitedList(arg))) + RPAR +
- LBRACE + Group(body) + RBRACE)
-decl = fundecl | vardecl
-program = ZeroOrMore(decl)
-
-program.ignore(cStyleComment)
-
-# set parser element names
-for vname in ("ifstmt whilestmt dowhilestmt returnstmt TYPE "
- "NAME fundecl vardecl program arg body stmt".split()):
- v = vars()[vname]
- v.setName(vname)
-
-#~ for vname in "fundecl stmt".split():
- #~ v = vars()[vname]
- #~ v.setDebug()
-
-test = r"""
-/* A factorial program */
-int
-putstr(char *s)
-{
- while(*s)
- putchar(*s++);
-}
-
-int
-fac(int n)
-{
- if (n == 0)
- return 1;
- else
- return n*fac(n-1);
-}
-
-int
-putn(int n)
-{
- if (9 < n)
- putn(n / 10);
- putchar((n%10) + '0');
-}
-
-int
-facpr(int n)
-{
- putstr("factorial ");
- putn(n);
- putstr(" = ");
- putn(fac(n));
- putstr("\n");
-}
-
-int
-main()
-{
- int i;
- i = 0;
- while(i < 10)
- facpr(i++);
- return 0;
-}
-"""
-
-ast = program.parseString(test,parseAll=True)
-ast.pprint()
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