diff options
Diffstat (limited to 'src/examples/oc.py')
| -rw-r--r-- | src/examples/oc.py | 107 |
1 files changed, 50 insertions, 57 deletions
diff --git a/src/examples/oc.py b/src/examples/oc.py index 77ea195..42b9d48 100644 --- a/src/examples/oc.py +++ b/src/examples/oc.py @@ -9,85 +9,78 @@ 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.
+ OC grammar
+ ==========
+ Terminals are in quotes, () is used for bracketing.
- program: decl*
+ program: decl*
- decl: vardecl
- fundecl
+ decl: vardecl
+ fundecl
- vardecl: type NAME ;
- type NAME "[" INT "]" ;
+ vardecl: type NAME ;
+ type NAME "[" INT "]" ;
- fundecl: type NAME "(" args ")" "{" body "}"
+ fundecl: type NAME "(" args ")" "{" body "}"
- args: /*empty*/
- ( arg "," )* arg
+ args: /*empty*/
+ ( arg "," )* arg
- arg: type NAME
+ arg: type NAME
- body: vardecl* stmt*
+ body: vardecl* stmt*
- stmt: ifstmt
- whilestmt
- dowhilestmt
- "return" expr ";"
- expr ";"
- "{" stmt* "}"
- ";"
+ stmt: ifstmt
+ whilestmt
+ dowhilestmt
+ "return" expr ";"
+ expr ";"
+ "{" stmt* "}"
+ ";"
- ifstmt: "if" "(" expr ")" stmt
- "if" "(" expr ")" stmt "else" stmt
+ ifstmt: "if" "(" expr ")" stmt
+ "if" "(" expr ")" stmt "else" stmt
- whilestmt: "while" "(" expr ")" stmt
+ whilestmt: "while" "(" expr ")" stmt
- dowhilestmt: "do" stmt "while" "(" expr ")" ";"
+ dowhilestmt: "do" stmt "while" "(" expr ")" ";"
- expr: expr binop expr
- unop expr
- expr "[" expr "]"
- "(" expr ")"
- expr "(" exprs ")"
- NAME
- INT
- CHAR
- STRING
+ expr: expr binop expr
+ unop expr
+ expr "[" expr "]"
+ "(" expr ")"
+ expr "(" exprs ")"
+ NAME
+ INT
+ CHAR
+ STRING
- exprs: /*empty*/
- (expr ",")* expr
+ exprs: /*empty*/
+ (expr ",")* expr
- binop: "+" | "-" | "*" | "/" | "%" |
- "=" |
- "<" | "==" | "!="
+ binop: "+" | "-" | "*" | "/" | "%" |
+ "=" |
+ "<" | "==" | "!="
- unop: "!" | "-" | "*"
+ unop: "!" | "-" | "*"
- type: "int" stars
- "char" stars
+ type: "int" stars
+ "char" stars
- 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")
+INT, CHAR, WHILE, DO, IF, ELSE, RETURN = map(Keyword,
+ "int char while do if else return".split())
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()
@@ -148,23 +141,23 @@ int putstr(char *s)
{
while(*s)
- putchar(*s++);
+ putchar(*s++);
}
int
fac(int n)
{
if (n == 0)
- return 1;
+ return 1;
else
- return n*fac(n-1);
+ return n*fac(n-1);
}
int
putn(int n)
{
if (9 < n)
- putn(n / 10);
+ putn(n / 10);
putchar((n%10) + '0');
}
@@ -184,10 +177,10 @@ main() int i;
i = 0;
while(i < 10)
- facpr(i++);
+ facpr(i++);
return 0;
}
"""
-ast = program.parseString(test,parseAll=True)
+ast = program.parseString(test, parseAll=True)
ast.pprint()
|