def stmtlist(self,pass_in_ATexpr=None):
""" parse a bunch of statements """
self.dbg_msg(u" STMTLIST ")
stlist = StmtList()
while( not self.lex.end_of_tokens() ):
self.dbg_msg(u"STMTLIST => STMT")
ptok = self.peek()
self.dbg_msg(u"STMTLIST "+unicode(ptok))
if ( self.debug ): print(u"peek @ ",unicode(ptok))
if ( ptok.kind == EzhilToken.END ):
self.dbg_msg(u"End token found");
break
elif ( ptok.kind == EzhilToken.DOWHILE ):
if ( self.debug ): print("DOWHILE token found")
break
elif( self.inside_if and
( ptok.kind == EzhilToken.ELSE
or ptok.kind == EzhilToken.ATRATEOF
or ptok.kind == EzhilToken.CASE
or ptok.kind == EzhilToken.OTHERWISE ) ):
break
elif( ptok.kind == EzhilToken.DEF ):
break
st = self.stmt(pass_in_ATexpr)
pass_in_ATexpr = None
stlist.append( st )
return stlist
def stmtlist(self):
""" parse a bunch of statements """
self.dbg_msg(" STMTLIST ")
stlist = StmtList()
while not self.lex.end_of_tokens():
self.dbg_msg("STMTLIST => STMT")
ptok = self.peek()
if ptok.kind == Token.END:
break
if not self.inside_if and (ptok.kind == Token.ELSE or ptok.kind == Token.ELSEIF):
break
st = self.stmt()
stlist.append(st)
return stlist
def stmtlist(self):
""" parse a bunch of statements """
self.dbg_msg(" STMTLIST ")
stlist = StmtList()
while (not self.lex.end_of_tokens()):
self.dbg_msg("STMTLIST => STMT")
ptok = self.peek()
if (ptok.kind == Token.END):
break
if (not self.inside_if and
(ptok.kind == Token.ELSE or ptok.kind == Token.ELSEIF)):
break
st = self.stmt()
stlist.append(st)
return stlist
def parse(self):
""" parser routine """
self.ast = StmtList()
while (not self.lex.end_of_tokens()):
self.dbg_msg("AST length = %d" % len(self.ast))
if (self.lex.peek().kind == Token.DEF):
self.dbg_msg("parsing for function")
## save function in a global table.
func = self.function()
self.warn_function_overrides(func.name)
self.function_map[func.name] = func
else:
self.dbg_msg("parsing for stmt")
st = self.stmt()
if (not self.parsing_function):
self.ast.append(st)
return self.ast
def stmtlist(self, pass_in_ATexpr=None):
""" parse a bunch of statements """
self.dbg_msg(" STMTLIST ")
stlist = StmtList()
while (not self.lex.end_of_tokens()):
self.dbg_msg("STMTLIST => STMT")
ptok = self.peek()
self.dbg_msg("STMTLIST " + str(ptok))
if (self.debug): print("peek @ ", str(ptok))
if (ptok.kind == EzhilToken.END):
self.dbg_msg("End token found")
break
elif (ptok.kind == EzhilToken.DOWHILE):
if (self.debug): print("DOWHILE token found")
break
elif (self.inside_if
and (ptok.kind == EzhilToken.ELSE or ptok.kind
== EzhilToken.ATRATEOF or ptok.kind == EzhilToken.CASE
or ptok.kind == EzhilToken.OTHERWISE)):
break
st = self.stmt(pass_in_ATexpr)
pass_in_ATexpr = None
stlist.append(st)
return stlist
def parse(self):
""" parser routine """
self.ast = StmtList()
while ( not self.lex.end_of_tokens() ):
self.dbg_msg( "AST length = %d"%len(self.ast) )
if ( self.lex.peek().kind == Token.DEF ):
self.dbg_msg ( "parsing for function" )
## save function in a global table.
func = self.function()
self.warn_function_overrides(func.name)
self.function_map[func.name]=func
else:
self.dbg_msg( "parsing for stmt" )
st = self.stmt()
if ( not self.parsing_function ):
self.ast.append(st)
return self.ast
def parse(self):
""" parser routine """
self.ast = StmtList(istoplevel=True)
self.dbg_msg(u" entering parser " )
while ( not self.lex.end_of_tokens() ):
self.dbg_msg( u"AST length = %d"%len(self.ast) )
if ( self.lex.peek().kind == EzhilToken.DEF ):
self.dbg_msg ( u"parsing for function" )
## save function in a global table.
func = self.function()
self.warn_function_overrides(func.name)
self.function_map[func.name]=func
self.ast.append(DeclarationStmt(func)) #add to AST
else:
self.dbg_msg( u"parsing for stmt" )
st = self.stmtlist()
if ( not self.parsing_function ):
self.ast.append(st)
return self.ast
class EzhilParser(Parser):
""" when you add new language feature, add a AST class
and its evaluate methods. Also add a parser method """
def __init__(self,lexer,fcn_map, builtin_map, dbg = False):
if ( not isinstance(lexer, EzhilLex) ):
raise RuntimeException(u"Cannot find Ezhil lexer class")
Parser.__init__(self,lexer,fcn_map,builtin_map,dbg)
self.open_if_stmts = 0
self.backtrack_atexpr = None
@staticmethod
def factory(lexer,fcn_map,builtin_map, dbg = False):
""" Factory method """
return EzhilParser(lexer,fcn_map,builtin_map, dbg)
def match(self,kind):
## if match return token, else ParseException
tok = self.dequeue()
if ( tok.kind != kind ):
raise ParseException(u"cannot find token "+ \
EzhilToken.get_name(kind) + u" got " \
+ unicode(tok) \
+ u" instead!")
return tok
def parse(self):
""" parser routine """
self.ast = StmtList()
self.dbg_msg(u" entering parser " )
while ( not self.lex.end_of_tokens() ):
self.dbg_msg( u"AST length = %d"%len(self.ast) )
if ( self.lex.peek().kind == EzhilToken.DEF ):
self.dbg_msg ( u"parsing for function" )
## save function in a global table.
func = self.function()
self.warn_function_overrides(func.name)
self.function_map[func.name]=func
self.ast.append(DeclarationStmt(func)) #add to AST
else:
self.dbg_msg( u"parsing for stmt" )
st = self.stmtlist()
if ( not self.parsing_function ):
self.ast.append(st)
return self.ast
def stmtlist(self,pass_in_ATexpr=None):
""" parse a bunch of statements """
self.dbg_msg(u" STMTLIST ")
stlist = StmtList()
while( not self.lex.end_of_tokens() ):
self.dbg_msg(u"STMTLIST => STMT")
ptok = self.peek()
self.dbg_msg(u"STMTLIST "+unicode(ptok))
if ( self.debug ): print(u"peek @ ",unicode(ptok))
if ( ptok.kind == EzhilToken.END ):
self.dbg_msg(u"End token found");
break
elif ( ptok.kind == EzhilToken.DOWHILE ):
if ( self.debug ): print("DOWHILE token found")
break
elif( self.inside_if and
( ptok.kind == EzhilToken.ELSE
or ptok.kind == EzhilToken.ATRATEOF
or ptok.kind == EzhilToken.CASE
or ptok.kind == EzhilToken.OTHERWISE ) ):
break
elif( ptok.kind == EzhilToken.DEF ):
break
st = self.stmt(pass_in_ATexpr)
pass_in_ATexpr = None
stlist.append( st )
return stlist
def parseSwitchStmt(self,exp):
## @ <ID/EXPR> SWITCH @( expr ) CASE {stmtlist} @( expr ) CASE {stmtlist} OTHERWISE {stmtlist} END
## implement as an if-elseif-else statement
self.dbg_msg("parsing SWITCH statement")
sw_tok = self.dequeue()
[l,c]=sw_tok.get_line_col()
self.inside_if = True
lhs=exp[0]
# enter this if-statement always
ifstmt = IfStmt( Number(1), None, None, l, c, self.debug)
self.if_stack.append(ifstmt)
self.dbg_msg("parsing SWITCH-body") #self.dbg_msg
ptok = self.peek()
equality_token = EzhilLexeme("=",EzhilToken.EQUALITY)
while ( ptok.kind == EzhilToken.ATRATEOF or ptok.kind == EzhilToken.OTHERWISE ):
self.inside_if = True
[l,c]=ptok.get_line_col()
if ( ptok.kind == EzhilToken.ATRATEOF ):
# parse elseif branch
self.dbg_msg("parsing CASE")
self.match( EzhilToken.ATRATEOF )
exp = self.valuelist();
self.dbg_msg("parsing CASE EXPR")
self.match( EzhilToken.CASE )
next_stmt = self.stmtlist()
expr = Expr( lhs, equality_token, exp[0], l, c, self.debug )
self.dbg_msg("building an Expr "+unicode(expr))
if not ifstmt.body :
ifstmt.expr = expr
ifstmt.body = next_stmt
else:
case_stmt = IfStmt(expr,next_stmt,None,l,c,self.debug);
ifstmt.append_stmt( case_stmt )
elif ( ptok.kind == EzhilToken.OTHERWISE ):
#parse else branch
self.dbg_msg("parsing OTHERWISE: ")
self.match( EzhilToken.OTHERWISE )
self.dbg_msg("parsing OTHERWISE-Body")
self.inside_if = False
body = self.stmtlist()
else_stmt = ElseStmt( body , l, c, self.debug)
if not ifstmt.body :
ifstmt.body = else_stmt
else:
ifstmt.append_stmt( else_stmt )
break
else:
self.inside_if = False
raise ParseException("SWITCH-CASE-OTHERWISE statement syntax is messed up")
ptok = self.peek()
self.dbg_msg("parsing SWITCH-CASE next bits "+unicode(ptok))
self.match( EzhilToken.END )
self.inside_if = False
self.dbg_msg("parsing -SWITCH-CASE- complete")
return ifstmt
def parseIfStmt(self,exp):
## @ <expression> if { stmtlist } @<expr> ELSEIF {stmtlist} ELSE <stmtlist> END
self.dbg_msg(u"parsing IF statement")
if_tok = self.dequeue()
[l,c]=if_tok.get_line_col()
self.inside_if = True
ifstmt = IfStmt( exp[0], None, None, l, c, self.debug)
self.if_stack.append(ifstmt)
self.dbg_msg(u"parsing IF-body")
body = self.stmtlist()
prev_body = body;
ifstmt.set_body( body )
ptok = self.peek()
while ( ptok.kind == EzhilToken.ATRATEOF or ptok.kind == EzhilToken.ELSE ):
self.inside_if = True
[l,c]=ptok.get_line_col()
if ( ptok.kind == EzhilToken.ATRATEOF ):
# parse elseif branch
self.dbg_msg(u"parsing ELSE-IF")
self.match( EzhilToken.ATRATEOF )
exp = self.valuelist();
self.dbg_msg(u"parsing ELSE-IF EXPR")
tok = self.peek()
if ( tok.kind != EzhilToken.ELSEIF ):
# maybe another IF statement, SWITCH-CASE or a WHILE loop, DO-WHILE loop etc.
next_stmt = self.stmtlist(exp) #pass in the expression
prev_body.append( next_stmt )
# append to previously scanned body.
else:
self.dbg_msg(u"parsing ELSE-IF-body")
self.match( EzhilToken.ELSEIF )
body = self.stmtlist()
prev_body = body
next_stmt = IfStmt(exp[0],body,None,l,c,self.debug)
self.dbg_msg(u"ELSEIF parsed correctly => "+unicode(next_stmt))
ifstmt.append_stmt( next_stmt )
elif ( ptok.kind == EzhilToken.ELSE ):
#parse else branch
self.dbg_msg(u"parsing stmt else: ")
self.match( EzhilToken.ELSE )
self.dbg_msg(u"parsing ELSE-Body")
self.inside_if = False
body = self.stmtlist()
prev_body = body;
else_stmt = ElseStmt( body , l, c, self.debug)
ifstmt.append_stmt( else_stmt )
break
else:
self.inside_if = False
raise ParseException(u"If-Else-If statement syntax is messed up")
ptok = self.peek()
self.dbg_msg(u"parsing -IF next bits "+unicode(ptok))
self.match( EzhilToken.END )
self.inside_if = False
self.dbg_msg(u"parsing -IF-complete")
return ifstmt
def stmt(self,pass_in_ATexpr=None):
""" try an assign, print, return, if or eval statement """
self.dbg_msg(u" STMT ")
ptok = self.peek()
self.dbg_msg(u"stmt: peeking at "+unicode(ptok))
if ( ptok.kind == EzhilToken.RETURN ):
## return <expression>
self.dbg_msg('enter->return: <expression>')
ret_tok = self.dequeue()
[l,c]=ret_tok.get_line_col();
if ( not self.parsing_function ):
raise ParseException( u"return statement outside of function body "+unicode(ret_tok))
rstmt = ReturnStmt(self.expr(),l,c,self.debug)
self.dbg_msg(u"return statement parsed")
return rstmt
elif ( ptok.kind == EzhilToken.PRINT ):
self.dbg_msg(u"stmt : print ")
self.currently_parsing.append( ptok )
## print <expression>
print_tok = self.dequeue()
[l,c]=print_tok.get_line_col();
exprlist_val = self.exprlist();
self.currently_parsing.pop()
return PrintStmt(exprlist_val,l,c,self.debug)
elif ( ptok.kind == EzhilToken.ATRATEOF or pass_in_ATexpr):
## @ <expression> {if | while | elseif}
if not pass_in_ATexpr:
at_tok = self.match(EzhilToken.ATRATEOF)
self.currently_parsing.append( at_tok )
exp = self.valuelist();
self.currently_parsing.pop()
else:
exp = pass_in_ATexpr
pass_in_ATexpr = None #use it just once
if( self.debug ): print ("return from valuelist ",unicode(exp))
ptok = self.peek();
if ( ptok.kind == EzhilToken.IF ):
return self.parseIfStmt(exp)
elif ( ptok.kind == EzhilToken.WHILE ):
## @ ( expr ) while { body } end
self.loop_stack.append(True)
self.dbg_msg(u"while-statement")
while_tok = self.dequeue()
self.currently_parsing.append( while_tok )
[l,c]=while_tok.get_line_col()
wexpr = exp[0];
body = self.stmtlist( )
self.match( EzhilToken.END)
whilestmt = WhileStmt(wexpr, body, l, c, self.debug)
self.loop_stack.pop()
self.currently_parsing.pop()
return whilestmt
elif ( ptok.kind == EzhilToken.SWITCH ):
return self.parseSwitchStmt(exp)
elif ( ptok.kind == EzhilToken.FOREACH ):
foreach_tok = self.dequeue()
self.currently_parsing.append(foreach_tok)
[l,c]=foreach_tok.get_line_col()
if ( self.debug ): print(u"parsing FOREACH stmt")
self.loop_stack.append(True)
self.dbg_msg(u"foreach-statement")
# convert to a for statement - building Ezhil AST - transformations
if not isinstance( exp[1], Identifier ):
raise ParseException(u" FOR-EACH statement "+unicode(foreach_tok) )
foreach_iter = exp[1];
iter = Identifier("__"+foreach_iter.id,l=0,c=-1);
eq_token = EzhilLexeme(u"=",EzhilToken.EQUALS)
plus_token = EzhilLexeme(u"+",EzhilToken.PLUS)
lt_token = EzhilLexeme(u"<",EzhilToken.LT)
if ( self.debug ): print(u"build init assign stmt")
init = AssignStmt( iter, eq_token , Number(0),l,c,self.debug)
if ( self.debug ): print(u"build cond expr")
VL1 = ValueList([exp[0]],l,c,self.debug)
cond = Expr( iter, lt_token, ExprCall( Identifier("len",l,c), VL1, l, c, self.debug ), l, c, self.debug )
if ( self.debug ): print("build plus1 stmt")
plus1_iter = Expr( iter, plus_token, Number(1), l, c, self.debug )
if ( self.debug ): print(u"build equals stmt")
update = AssignStmt( iter, eq_token , plus1_iter ,l,c,self.debug)
body = self.stmtlist() #parse body
# and insert artifical update variable in body
VL2 = ValueList([exp[0],iter],l,c,self.debug)
extract_foreach_iter_from_list = ExprCall( Identifier("__getitem__",l,c), VL2,l,c,self.debug);
foreach_iter_Assign = AssignStmt( foreach_iter, eq_token , extract_foreach_iter_from_list, l,c,self.debug )
body.List.insert( 0,foreach_iter_Assign)
# complete FOREACH stmt
self.match( EzhilToken.END)
self.currently_parsing.pop()
foreach_stmt = ForStmt(init, cond, update, body, l, c, self.debug);
self.loop_stack.pop();
if ( self.debug ): print(u"completed parsing FOR-EACH loop",unicode(foreach_stmt))
return foreach_stmt
elif ( ptok.kind == EzhilToken.FOR ):
## Fixme : empty for loops not allowed.
""" For ( exp1 , exp2 , exp3 ) stmtlist end"""
if ( self.debug ): print("parsing FOR stmt")
self.loop_stack.append(True)
self.dbg_msg("for-statement")
for_tok = self.peek()
self.currently_parsing.append(for_tok)
if ( self.debug ): print("matching for STMT",unicode(self.peek()))
self.match( EzhilToken.FOR )
if ( self.debug ): print("matched for STMT",unicode(self.peek()))
[l,c]= for_tok.get_line_col();
init,cond,update = exp[0],exp[1],exp[2]
if ( self.debug ): print("extract 3 parts",unicode(init),unicode(cond),unicode(update))
body = self.stmtlist()
self.match( EzhilToken.END)
self.currently_parsing.pop()
if ( self.debug ): print("body of loop",unicode(body))
forstmt = ForStmt(init, cond, update, body, l, c, self.debug);
self.loop_stack.pop();
if ( self.debug ): print("completed parsing FOR loop",unicode(forstmt))
return forstmt
elif ( ptok.kind == EzhilToken.DO ):
if ( self.debug ): print("parsing DO-WHILE statement")
self.loop_stack.append(True)
do_tok = self.dequeue()
self.currently_parsing.append(do_tok)
[l,c]=do_tok.get_line_col()
body = self.stmtlist()
if ( self.debug ): print("parsed body")
self.match(EzhilToken.DOWHILE)
self.match(EzhilToken.ATRATEOF)
exp = self.valuelist();
if ( self.debug ): print("parsed EXP",exp[0])
doWhileStmt = DoWhileStmt(exp[0], body, l, c, self.debug)
self.loop_stack.pop()
self.currently_parsing.pop()
return doWhileStmt
elif ( ptok.kind == EzhilToken.BREAK ):
## break, must be in loop-environment
self.dbg_msg("break-statement");
break_tok = self.dequeue();
[l,c]=break_tok.get_line_col()
self.check_loop_stack(); ##raises a parse error
brkstmt = BreakStmt( l, c, self.debug);
return brkstmt
elif ( ptok.kind == EzhilToken.CONTINUE ):
## continue, must be in loop-environment
self.dbg_msg("continue-statement");
cont_tok = self.dequeue();
[l,c]=cont_tok.get_line_col()
self.check_loop_stack(); ##raises a parse error
cntstmt = ContinueStmt( l, c, self.debug);
return cntstmt
else:
## lval := rval
ptok = self.peek()
self.currently_parsing.append(ptok)
[l,c] = ptok.get_line_col()
lhs = self.expr()
self.dbg_msg("parsing expr: "+unicode(lhs))
ptok = self.peek()
if ( ptok.kind in EzhilToken.ASSIGNOP ):
assign_tok = self.dequeue()
rhs = self.expr()
[l,c]=assign_tok.get_line_col()
self.currently_parsing.pop()
return AssignStmt( lhs, assign_tok, rhs, l, c, self.debug)
self.currently_parsing.pop()
return EvalStmt( lhs, l, c, self.debug )
raise ParseException("parsing Statement, unknown operators" + unicode(ptok))
def function(self):
""" def[kw] fname[id] (arglist) {body} end[kw] """
if ( self.parsing_function ):
self.parsing_function = False
raise ParseException(u" Nested functions not allowed! "+unicode(self.last_token()))
self.parsing_function = True
def_tok = self.dequeue()
if ( def_tok.kind != EzhilToken.DEF ):
raise ParseException(u"unmatched 'def' in function " +unicode(def_tok))
id_tok = self.dequeue()
if ( id_tok.kind != EzhilToken.ID ):
raise ParseException(u"expected identifier in function"+unicode(id_tok))
arglist = self.arglist()
self.dbg_msg( u"finished parsing arglist" )
body = self.stmtlist()
self.match( EzhilToken.END )
[l,c] = def_tok.get_line_col()
fval = Function( id_tok.val, arglist, body, l, c, self.debug )
self.parsing_function = False
self.dbg_msg( u"finished parsing function" )
return fval
def valuelist(self):
"""parse: ( expr_1 , expr_2, ... ) """
valueList = list()
self.dbg_msg(u"valuelist: ")
lparen_tok = self.match( EzhilToken.LPAREN )
while ( self.peek().kind != EzhilToken.RPAREN ):
val = self.expr()
if ( self.debug ): print(u"val = ",unicode(val))
ptok = self.peek()
if ( self.debug ) : print(u"ptok = ",unicode(ptok),unicode(ptok.kind),unicode(EzhilToken.ASSIGNOP))
if ( ptok.kind in EzhilToken.ASSIGNOP ):
assign_tok = self.dequeue()
rhs = self.expr()
[l,c]=assign_tok.get_line_col()
lhs = val
val = AssignStmt( lhs, assign_tok, rhs, l, c, self.debug)
if ( self.debug ): print(u"AssignStmt = ",unicode(val))
ptok = self.peek()
else:
if ( self.debug ): print(u"No-Assign // Expr =",unicode(val))
self.dbg_msg(u"valuelist-expr: "+unicode(val))
valueList.append( val )
if ( ptok.kind == EzhilToken.RPAREN ):
break
elif ( ptok.kind == EzhilToken.COMMA ):
self.match( EzhilToken.COMMA )
else:
raise ParseException(u" function call argument list "+unicode(ptok))
self.match( EzhilToken.RPAREN )
[l,c] = lparen_tok.get_line_col()
return ValueList(valueList, l, c, self.debug )
def arglist(self):
"""parse: ( arg_1, arg_2, ... ) """
self.dbg_msg( u" ARGLIST " )
args = list()
lparen_tok = self.match( EzhilToken.LPAREN )
while ( self.peek().kind != EzhilToken.RPAREN ):
arg_name = self.dequeue()
args.append( arg_name.val )
ptok = self.peek()
if ( ptok.kind == EzhilToken.RPAREN ):
break
elif ( ptok.kind == EzhilToken.COMMA ):
self.match( EzhilToken.COMMA )
else:
raise ParseException(u" function definition argument list "
+unicode(ptok))
self.match( EzhilToken.RPAREN )
[l,c] = lparen_tok.get_line_col()
return ArgList(args , l, c, self.debug )
def exprlist(self):
""" EXPRLIST : EXPR, EXPRLIST
## EXPRLIST : EXPR """
self.dbg_msg( u" EXPRLIST " )
exprs=[]
comma_tok = None
l = 0; c = 0
while ( not self.lex.end_of_tokens() ):
exprs.append(self.expr())
if self.lex.peek().kind != EzhilToken.COMMA:
break
tok = self.match( EzhilToken.COMMA)
if ( not comma_tok ):
comma_tok = tok
if ( comma_tok ):
[l,c] = comma_tok.get_line_col()
self.dbg_msg(u"finished expression list")
return ExprList(exprs, l, c, self.debug)
def expr(self):
self.dbg_msg( u" EXPR " )
val1=self.term()
res=val1
ptok = self.peek()
if ptok.kind in EzhilToken.ADDSUB:
binop=self.dequeue()
if ( ptok.kind == EzhilToken.MINUS ):
val2 = self.term()
else:
val2=self.expr()
[l,c] = binop.get_line_col()
res=Expr(val1,binop,val2, l, c, self.debug )
elif ptok.kind == EzhilToken.LPAREN:
## function call
if ( not isinstance(res, Identifier) ):
raise ParseException(u"invalid function call"+unicode(ptok))
[l,c] = ptok.get_line_col()
vallist = self.valuelist()
res=ExprCall( res, vallist, l, c, self.debug )
ptok = self.peek()
while ptok.kind in EzhilToken.BINOP:
binop = self.dequeue()
[l,c] = binop.get_line_col()
res = Expr( res, binop,self.expr(), l,c,self.debug)
ptok = self.peek()
return res
def term(self):
""" this is a grammar abstraction;
but AST only has Expr elements"""
self.dbg_msg( "term" )
val1=self.factor()
res=val1
tok = self.peek()
if ( tok.kind in EzhilToken.MULDIV
or tok.kind in EzhilToken.COMPARE
or tok.kind in EzhilToken.EXPMOD
or tok.kind in EzhilToken.BITWISE_AND_LOGICAL ):
binop=self.dequeue()
val2=self.term()
[l,c] = binop.get_line_col()
res=Expr(val1,binop,val2, l, c, self.debug)
return res
def factor(self):
self.dbg_msg( "factor" )
tok=self.peek()
if tok.kind == EzhilToken.LPAREN:
lparen_tok = self.dequeue()
val=self.expr()
if self.dequeue().kind!= EzhilToken.RPAREN:
raise SyntaxError("Missing Parens "+unicode(self.last_token()))
elif tok.kind == EzhilToken.NUMBER:
tok_num = self.dequeue()
[l, c] = tok_num.get_line_col()
val = Number( tok.val , l, c, self.debug )
elif tok.kind == EzhilToken.LOGICAL_NOT:
tok_not = self.dequeue()
[l, c] = tok_not.get_line_col()
val = UnaryExpr( self.expr(), tok_not , l, c, self.debug )
self.dbg_msg("completed parsing unary expression"+unicode(val))
elif tok.kind == EzhilToken.ID:
tok_id = self.dequeue()
[l, c] = tok_id.get_line_col()
val = Identifier( tok.val , l, c, self.debug )
ptok = self.peek()
self.dbg_msg(u"factor: "+unicode(ptok) + u" / "+ unicode(tok) )
if ( ptok.kind == EzhilToken.LPAREN ):
## function call
[l, c] = ptok.get_line_col()
vallist = self.valuelist()
val=ExprCall( val, vallist, l, c, self.debug )
elif ( ptok.kind == EzhilToken.LSQRBRACE ):
## indexing a array type variable or ID
[l,c] = ptok.get_line_col()
## replace with a call to __getitem__
exp = self.factor();
if ( hasattr(exp,'__getitem__') ):
VL2 = ValueList([val,exp[0]],l,c,self.debug)
else:
# when exp is a expression
VL2 = ValueList([val,exp],l,c,self.debug)
val = ExprCall( Identifier("__getitem__",l,c), VL2,l,c,self.debug)
for itr in range(1,len(exp)):
VL2 = ValueList([val,exp[itr]],l,c,self.debug)
val = ExprCall( Identifier("__getitem__",l,c), VL2,l,c,self.debug)
#raise ParseException("array indexing implemented"+unicode(ptok));
elif ( ptok.kind == EzhilToken.LCURLBRACE ):
val=None
raise ParseException("dictionary indexing implemented"+unicode(ptok));
elif tok.kind == EzhilToken.STRING :
str_tok = self.dequeue()
[l,c] = str_tok.get_line_col()
val = String( tok.val , l, c, self.debug )
elif tok.kind in EzhilToken.ADDSUB:
unop = self.dequeue();
[l, c] = unop.get_line_col()
val=Expr(Number(0),unop,self.term(),l,c,self.debug);
elif tok.kind == EzhilToken.LCURLBRACE:
# creating a list/dictionary expression
dict_start = self.dequeue();
val = Dict()
while( True ):
if ( self.peek().kind == EzhilToken.RCURLBRACE ):
break;
exprkey = self.expr()
tok_colon = self.match(EzhilToken.COLON)
exprval = self.expr()
val.update( {exprkey : exprval} )
if self.debug : print(self.peek().__class__,self.peek())
if ( self.peek().kind == EzhilToken.RCURLBRACE ):
break
else:
assert( self.peek().kind == EzhilToken.COMMA)
self.dequeue()
assert( self.peek().kind == EzhilToken.RCURLBRACE )
list_end = self.dequeue()
elif tok.kind == EzhilToken.LSQRBRACE:
# creating a list/array expression
list_start = self.dequeue();
val = Array()
while( True ):
if ( self.peek().kind == EzhilToken.RSQRBRACE ):
break;
exprval = self.expr()
val.append( exprval )
if self.debug : print(self.peek().__class__,self.peek())
if ( self.peek().kind == EzhilToken.RSQRBRACE ):
break
else:
assert( self.peek().kind == EzhilToken.COMMA)
self.dequeue()
assert( self.peek().kind == EzhilToken.RSQRBRACE )
list_end = self.dequeue()
else:
raise ParseException("Expected Number, found something "+unicode(tok))
self.dbg_msg( u"factor-returning: "+unicode(val) )
return val
class Parser(DebugUtils):
""" when you add new language feature, add a AST class
and its evaluate methods. Also add a parser method """
def __init__(self,lexer,fcn_map, builtin_map, dbg = False):
DebugUtils.__init__(self,dbg)
self.parsing_function = False
self.lex=lexer
self.ast=None
self.currently_parsing = [] # stack, just in case we should have parse errors
self.function_map = fcn_map #parsed functions
self.builtin_map = builtin_map #pointers to builtin functions
self.if_stack = [] #parsing if-statements
self.loop_stack = [] #parsing while-statements
self.last_tok = None ## handle to last token dequeued
self.inside_if = False
def reset(self):
"""reset parser, and lexer, when stuff gets messed up"""
self.inside_if = False
self.loop_stack = []
self.if_stack = []
self.currently_parsing = []
self.lex.reset()
return
def check_loop_stack(self):
if ( len(self.loop_stack) == 0 ):
raise ParseException(u"break/continue statement outside any loop, near" + str(self.last_token()));
return len(self.loop_stack);
def check_if_stack(self):
if ( len(self.if_stack) == 0 ):
raise ParseException(u"unmatched else statement, near" + str(self.last_token()))
return len(self.if_stack)
def last_token(self):
return self.last_tok
def peek(self):
ptok = self.lex.peek()
self.dbg_msg(u"peek: " + unicode(ptok))
return ptok
def dequeue(self):
tok = self.lex.dequeue()
self.last_tok = tok
self.dbg_msg( u"deqeue: " + unicode(tok) )
return tok
def match(self,kind):
## if match return token, else ParseException
tok = self.dequeue()
if ( tok.kind != kind ):
raise ParseException(u"cannot find token "+ \
Token.get_name(kind) + u" got " \
+ unicode(tok) + u" instead!")
return tok
def __repr__(self):
rval = u"[Interpreter: "
rval = rval + u"[Functions["
for k in list(self.function_map.keys()):
rval = rval + u"\n "+ str(self.function_map[k])
rval = rval + u"]] "+ str(self.ast) + u"]\n"
return rval
def warn_function_overrides( self, func_name ):
## used in defining user-functions to see
## if they shadow builtins.
val = ( func_name in self.function_map \
or func_name in self.builtin_map )
if ( val ):
print(u"WARNING: function %s overrides builtin"%(func_name))
return val
def parse(self):
""" parser routine """
self.ast = StmtList()
while ( not self.lex.end_of_tokens() ):
self.dbg_msg( "AST length = %d"%len(self.ast) )
if ( self.lex.peek().kind == Token.DEF ):
self.dbg_msg ( "parsing for function" )
## save function in a global table.
func = self.function()
self.warn_function_overrides(func.name)
self.function_map[func.name]=func
else:
self.dbg_msg( "parsing for stmt" )
st = self.stmt()
if ( not self.parsing_function ):
self.ast.append(st)
return self.ast
def stmtlist(self):
""" parse a bunch of statements """
self.dbg_msg(" STMTLIST ")
stlist = StmtList()
while( not self.lex.end_of_tokens() ):
self.dbg_msg("STMTLIST => STMT")
ptok = self.peek()
if ( ptok.kind == Token.END ):
break
if ( not self.inside_if and
( ptok.kind == Token.ELSE
or ptok.kind == Token.ELSEIF ) ):
break
st = self.stmt()
stlist.append( st )
return stlist
def stmt(self):
""" try an assign, print, return, if or eval statement """
self.dbg_msg(" STMT ")
ptok = self.peek()
self.dbg_msg("stmt: peeking at "+unicode(ptok))
if ( ptok.kind == Token.RETURN ):
## return <expression>
ret_tok = self.dequeue()
[l,c]=ret_tok.get_line_col();
rstmt = ReturnStmt(self.expr(),l,c,self.debug)
self.dbg_msg("return statement parsed")
return rstmt
elif ( ptok.kind == Token.PRINT ):
## print <expression>
print_tok = self.dequeue()
[l,c]=print_tok.get_line_col();
return PrintStmt(self.exprlist(),l,c,self.debug)
elif ( ptok.kind == Token.IF ):
## if <expression> stmtlist end
if_tok = self.dequeue()
[l,c]=if_tok.get_line_col();
exp = self.expr()
ifstmt = IfStmt( exp, None, None, l, c, self.debug)
self.if_stack.append(ifstmt)
body = self.stmtlist()
ifstmt.set_body( body )
ptok = self.peek()
if ( ptok.kind in [Token.ELSEIF, Token.ELSE] ):
self.inside_if = True
next_stmt = self.stmtlist()
self.inside_if = False
ifstmt.append_stmt( next_stmt )
self.match(Token.END)
return ifstmt
elif ( ptok.kind == Token.ELSEIF ):
## elseif <expression> stmtlist
elseif_tok = self.dequeue()
[l,c]=elseif_tok.get_line_col();
self.check_if_stack()
exp = self.expr()
elseif_stmt = IfStmt( exp, None, None, l, c, self.debug )
ifstmt = self.if_stack[-1]
ifstmt.append_stmt( elseif_stmt )
self.if_stack.pop()
self.if_stack.append( elseif_stmt )
body = self.stmtlist( )
elseif_stmt.set_body ( body )
return elseif_stmt
elif ( ptok.kind == Token.ELSE ):
## else stmtlist
self.check_if_stack()
ifstmt = self.if_stack.pop()
self.dbg_msg("stmt-else: ")
else_tok = self.dequeue()
[l,c]=else_tok.get_line_col()
body = self.stmtlist()
else_stmt = ElseStmt( body , l, c, self.debug)
ifstmt.append_stmt( else_stmt )
return else_stmt
elif ( ptok.kind == Token.FOR ):
## Fixme : empty for loops not allowed.
""" For ( exp1 ; exp2 ; exp3 ) stmtlist end"""
self.loop_stack.append(True)
self.dbg_msg("for-statement")
for_tok = self.dequeue()
self.match(Token.LPAREN)
lhs = self.expr()
init = lhs
ptok = self.peek()
if ( ptok.kind in Token.ASSIGNOP ):
assign_tok = self.dequeue()
[l,c]=assign_tok.get_line_col();
rhs = self.expr()
init = AssignStmt( lhs, assign_tok, rhs, l, c, self.debug)
self.match(Token.COMMA )
cond = self.expr();
self.match(Token.COMMA )
lhs = self.expr()
update = lhs
ptok = self.peek()
if ( ptok.kind in Token.ASSIGNOP ):
assign_tok = self.dequeue()
[l,c]=assign_tok.get_line_col()
rhs = self.expr()
update = AssignStmt( lhs, assign_tok, rhs, l, c, self.debug)
self.match(Token.RPAREN);
body = self.stmtlist( )
self.match(Token.END)
[l,c]= for_tok.get_line_col();
forstmt = ForStmt(init, cond, update, body, l, c, self.debug);
self.loop_stack.pop();
return forstmt
elif ( ptok.kind == Token.WHILE ):
## while ( expr ) body end
self.loop_stack.append(True);
self.dbg_msg("while-statement");
while_tok = self.dequeue();
[l,c]=while_tok.get_line_col()
wexpr = self.expr();
body = self.stmtlist( )
self.match(Token.END)
whilestmt = WhileStmt(wexpr, body, l, c, self.debug);
self.loop_stack.pop();
return whilestmt
elif ( ptok.kind == Token.BREAK ):
## break, must be in loop-environment
self.dbg_msg("break-statement");
break_tok = self.dequeue();
[l,c]=break_tok.get_line_col()
self.check_loop_stack(); ##raises a parse error
brkstmt = BreakStmt( l, c, self.debug);
return brkstmt
elif ( ptok.kind == Token.CONTINUE ):
## continue, must be in loop-environment
self.dbg_msg("continue-statement");
cont_tok = self.dequeue();
[l,c]=cont_tok.get_line_col()
self.check_loop_stack(); ##raises a parse error
cntstmt = ContinueStmt( l, c, self.debug);
return cntstmt
else:
## lval := rval
ptok = self.peek()
[l,c] = ptok.get_line_col()
lhs = self.expr()
self.dbg_msg("parsing expr: "+str(lhs))
ptok = self.peek()
if ( ptok.kind in Token.ASSIGNOP ):
assign_tok = self.dequeue()
rhs = self.expr()
[l,c]=assign_tok.get_line_col()
return AssignStmt( lhs, assign_tok, rhs, l, c, self.debug)
return EvalStmt( lhs, l, c, self.debug )
raise ParseException("parsing Statement, unkown operators" + unicode(ptok))
def function(self):
""" def[kw] fname[id] (arglist) {body} end[kw] """
if ( self.parsing_function ):
raise ParseException(" Nested functions not allowed! ")
self.parsing_function = True
def_tok = self.dequeue()
if ( def_tok.kind != Token.DEF ):
raise ParseException("unmatched 'def' in function " +str(def_tok))
id_tok = self.dequeue()
if ( id_tok.kind != Token.ID ):
raise ParseException("expected identifier in function"+str(id_tok))
arglist = self.arglist()
self.dbg_msg( "finished parsing arglist" )
body = self.stmtlist()
self.match( Token.END )
[l,c] = def_tok.get_line_col()
fval = Function( id_tok.val, arglist, body, l, c, self.debug )
self.parsing_function = False
self.dbg_msg( "finished parsing function" )
return fval
def valuelist(self):
"""parse: ( expr_1 , expr_2, ... ) """
valueList = list()
self.dbg_msg("valuelist: ")
lparen_tok = self.match( Token.LPAREN )
while ( self.peek().kind != Token.RPAREN ):
val = self.expr()
self.dbg_msg("valuelist-expr: "+str(val))
valueList.append( val )
ptok = self.peek()
if ( ptok.kind == Token.RPAREN ):
break
elif ( ptok.kind == Token.COMMA ):
self.match( Token.COMMA )
else:
raise ParseException(" function call argument list "+unicode(ptok))
self.match( Token.RPAREN )
[l,c] = lparen_tok.get_line_col()
return ValueList(valueList, l, c, self.debug )
def arglist(self):
"""parse: ( arg_1, arg_2, ... ) """
self.dbg_msg( " ARGLIST " )
args = list()
lparen_tok = self.match( Token.LPAREN )
while ( self.peek().kind != Token.RPAREN ):
arg_name = self.dequeue()
args.append( arg_name.val )
ptok = self.peek()
if ( ptok.kind == Token.RPAREN ):
break
elif ( ptok.kind == Token.COMMA ):
self.match( Token.COMMA )
else:
raise ParseException(" function definition argument list "
+unicode(ptok))
self.match( Token.RPAREN )
[l,c] = lparen_tok.get_line_col()
return ArgList(args , l, c, self.debug )
def exprlist(self):
""" EXPRLIST : EXPR, EXPRLIST
## EXPRLIST : EXPR """
self.dbg_msg( " EXPRLIST " )
exprs=[]
comma_tok = None
l = 0; c = 0
while ( not self.lex.end_of_tokens() ):
exprs.append(self.expr())
if self.lex.peek().kind != Token.COMMA:
break
tok = self.match(Token.COMMA)
if ( not comma_tok ):
comma_tok = tok
if ( comma_tok ):
[l,c] = comma_tok.get_line_col()
self.dbg_msg("finished expression list")
return ExprList(exprs, l, c, self.debug)
def expr(self):
self.dbg_msg( " EXPR " )
val1=self.term()
res=val1
ptok = self.peek()
if ptok.kind in Token.ADDSUB:
binop=self.dequeue()
val2=self.expr()
[l,c] = binop.get_line_col()
res=Expr(val1,binop,val2, l, c, self.debug )
elif ptok.kind == Token.LPAREN:
## function call -OR- array type.
if ( res.__class__ != Identifier ):
raise ParseException("invalid function call"+unicode(ptok))
[l,c] = ptok.get_line_col()
vallist = self.valuelist()
res=ExprCall( res, vallist, l, c, self.debug )
return res
def term(self):
""" this is a grammar abstraction;
but AST only has Expr elements"""
self.dbg_msg( "term" )
val1=self.factor()
res=val1
tok = self.peek()
if ( tok.kind in Token.MULDIV
or tok.kind in Token.COMPARE
or tok.kind in Token.EXPMOD ):
binop=self.dequeue()
val2=self.expr()
[l,c] = binop.get_line_col()
res=Expr(val1,binop,val2, l, c, self.debug)
return res
def factor(self):
self.dbg_msg( "factor" )
tok=self.peek()
if tok.kind == Token.LPAREN:
lparen_tok = self.dequeue()
val=self.expr()
if self.dequeue().kind!=Token.RPAREN:
raise SyntaxError("Missing Parens")
elif tok.kind == Token.NUMBER:
tok_num = self.dequeue()
[l, c] = tok_num.get_line_col()
val = Number( tok.val , l, c, self.debug )
elif tok.kind == Token.ID:
tok_id = self.dequeue()
[l, c] = tok_id.get_line_col()
val = Identifier( tok.val , l, c, self.debug )
ptok = self.peek()
self.dbg_msg("factor: "+unicode(ptok) + " / "+str(tok) )
if ( ptok.kind == Token.LPAREN ):
## function call
[l, c] = ptok.get_line_col()
vallist = self.valuelist()
val=ExprCall( val, vallist, l, c, self.debug )
elif ( ptok.kind == Token.LSQRBRACE ):
## array type
val=None
raise ParseException("arrays not implemented"+unicode(ptok));
elif tok.kind == Token.STRING :
str_tok = self.dequeue()
[l,c] = str_tok.get_line_col()
val = String( tok.val , l, c, self.debug )
else:
raise ParseException("Expected Number, found something "+str(tok))
self.dbg_msg( "factor-returning: "+str(val) )
return val
class Parser(DebugUtils):
""" when you add new language feature, add a AST class
and its evaluate methods. Also add a parser method """
def __init__(self, lexer, fcn_map, builtin_map, dbg=False):
DebugUtils.__init__(self, dbg)
self.parsing_function = False
self.lex = lexer
self.ast = None
self.currently_parsing = [
] # stack, just in case we should have parse errors
self.function_map = fcn_map #parsed functions
self.builtin_map = builtin_map #pointers to builtin functions
self.if_stack = [] #parsing if-statements
self.loop_stack = [] #parsing while-statements
self.last_tok = None ## handle to last token dequeued
self.inside_if = False
def reset(self):
"""reset parser, and lexer, when stuff gets messed up"""
self.inside_if = False
self.loop_stack = []
self.if_stack = []
self.currently_parsing = []
self.lex.reset()
return
def check_loop_stack(self):
if (len(self.loop_stack) == 0):
raise ParseException(
"break/continue statement outside any loop, near" +
str(self.last_token()))
return len(self.loop_stack)
def check_if_stack(self):
if (len(self.if_stack) == 0):
raise ParseException("unmatched else statement, near" +
str(self.last_token()))
return len(self.if_stack)
def last_token(self):
return self.last_tok
def peek(self):
ptok = self.lex.peek()
self.dbg_msg("peek: " + str(ptok))
return ptok
def dequeue(self):
tok = self.lex.dequeue()
self.last_tok = tok
self.dbg_msg("deqeue: " + str(tok))
return tok
def match(self, kind):
## if match return token, else ParseException
tok = self.dequeue()
if (tok.kind != kind):
raise ParseException("cannot find token "+ \
Token.get_name(kind) + " got " \
+ str(tok) \
+ " instead!")
return tok
def __repr__(self):
rval = "[Interpreter: "
rval = rval + "[Functions["
for k in list(self.function_map.keys()):
rval = rval + "\n " + str(self.function_map[k])
rval = rval + "]] " + str(self.ast) + "]\n"
return rval
def warn_function_overrides(self, func_name):
## used in defining user-functions to see
## if they shadow builtins.
val = ( func_name in self.function_map \
or func_name in self.builtin_map )
if (val):
print("WARNING: function %s overrides builtin" % (func_name))
return val
def parse(self):
""" parser routine """
self.ast = StmtList()
while (not self.lex.end_of_tokens()):
self.dbg_msg("AST length = %d" % len(self.ast))
if (self.lex.peek().kind == Token.DEF):
self.dbg_msg("parsing for function")
## save function in a global table.
func = self.function()
self.warn_function_overrides(func.name)
self.function_map[func.name] = func
else:
self.dbg_msg("parsing for stmt")
st = self.stmt()
if (not self.parsing_function):
self.ast.append(st)
return self.ast
def stmtlist(self):
""" parse a bunch of statements """
self.dbg_msg(" STMTLIST ")
stlist = StmtList()
while (not self.lex.end_of_tokens()):
self.dbg_msg("STMTLIST => STMT")
ptok = self.peek()
if (ptok.kind == Token.END):
break
if (not self.inside_if and
(ptok.kind == Token.ELSE or ptok.kind == Token.ELSEIF)):
break
st = self.stmt()
stlist.append(st)
return stlist
def stmt(self):
""" try an assign, print, return, if or eval statement """
self.dbg_msg(" STMT ")
ptok = self.peek()
self.dbg_msg("stmt: peeking at " + str(ptok))
if (ptok.kind == Token.RETURN):
## return <expression>
ret_tok = self.dequeue()
[l, c] = ret_tok.get_line_col()
rstmt = ReturnStmt(self.expr(), l, c, self.debug)
self.dbg_msg("return statement parsed")
return rstmt
elif (ptok.kind == Token.PRINT):
## print <expression>
print_tok = self.dequeue()
[l, c] = print_tok.get_line_col()
return PrintStmt(self.exprlist(), l, c, self.debug)
elif (ptok.kind == Token.IF):
## if <expression> stmtlist end
if_tok = self.dequeue()
[l, c] = if_tok.get_line_col()
exp = self.expr()
ifstmt = IfStmt(exp, None, None, l, c, self.debug)
self.if_stack.append(ifstmt)
body = self.stmtlist()
ifstmt.set_body(body)
ptok = self.peek()
if (ptok.kind in [Token.ELSEIF, Token.ELSE]):
self.inside_if = True
next_stmt = self.stmtlist()
self.inside_if = False
ifstmt.append_stmt(next_stmt)
self.match(Token.END)
return ifstmt
elif (ptok.kind == Token.ELSEIF):
## elseif <expression> stmtlist
elseif_tok = self.dequeue()
[l, c] = elseif_tok.get_line_col()
self.check_if_stack()
exp = self.expr()
elseif_stmt = IfStmt(exp, None, None, l, c, self.debug)
ifstmt = self.if_stack[-1]
ifstmt.append_stmt(elseif_stmt)
self.if_stack.pop()
self.if_stack.append(elseif_stmt)
body = self.stmtlist()
elseif_stmt.set_body(body)
return elseif_stmt
elif (ptok.kind == Token.ELSE):
## else stmtlist
self.check_if_stack()
ifstmt = self.if_stack.pop()
self.dbg_msg("stmt-else: ")
else_tok = self.dequeue()
[l, c] = else_tok.get_line_col()
body = self.stmtlist()
else_stmt = ElseStmt(body, l, c, self.debug)
ifstmt.append_stmt(else_stmt)
return else_stmt
elif (ptok.kind == Token.FOR):
## Fixme : empty for loops not allowed.
""" For ( exp1 ; exp2 ; exp3 ) stmtlist end"""
self.loop_stack.append(True)
self.dbg_msg("for-statement")
for_tok = self.dequeue()
self.match(Token.LPAREN)
lhs = self.expr()
init = lhs
ptok = self.peek()
if (ptok.kind in Token.ASSIGNOP):
assign_tok = self.dequeue()
[l, c] = assign_tok.get_line_col()
rhs = self.expr()
init = AssignStmt(lhs, assign_tok, rhs, l, c, self.debug)
self.match(Token.COMMA)
cond = self.expr()
self.match(Token.COMMA)
lhs = self.expr()
update = lhs
ptok = self.peek()
if (ptok.kind in Token.ASSIGNOP):
assign_tok = self.dequeue()
[l, c] = assign_tok.get_line_col()
rhs = self.expr()
update = AssignStmt(lhs, assign_tok, rhs, l, c, self.debug)
self.match(Token.RPAREN)
body = self.stmtlist()
self.match(Token.END)
[l, c] = for_tok.get_line_col()
forstmt = ForStmt(init, cond, update, body, l, c, self.debug)
self.loop_stack.pop()
return forstmt
elif (ptok.kind == Token.WHILE):
## while ( expr ) body end
self.loop_stack.append(True)
self.dbg_msg("while-statement")
while_tok = self.dequeue()
[l, c] = while_tok.get_line_col()
wexpr = self.expr()
body = self.stmtlist()
self.match(Token.END)
whilestmt = WhileStmt(wexpr, body, l, c, self.debug)
self.loop_stack.pop()
return whilestmt
elif (ptok.kind == Token.BREAK):
## break, must be in loop-environment
self.dbg_msg("break-statement")
break_tok = self.dequeue()
[l, c] = break_tok.get_line_col()
self.check_loop_stack()
##raises a parse error
brkstmt = BreakStmt(l, c, self.debug)
return brkstmt
elif (ptok.kind == Token.CONTINUE):
## continue, must be in loop-environment
self.dbg_msg("continue-statement")
cont_tok = self.dequeue()
[l, c] = cont_tok.get_line_col()
self.check_loop_stack()
##raises a parse error
cntstmt = ContinueStmt(l, c, self.debug)
return cntstmt
else:
## lval := rval
ptok = self.peek()
[l, c] = ptok.get_line_col()
lhs = self.expr()
self.dbg_msg("parsing expr: " + str(lhs))
ptok = self.peek()
if (ptok.kind in Token.ASSIGNOP):
assign_tok = self.dequeue()
rhs = self.expr()
[l, c] = assign_tok.get_line_col()
return AssignStmt(lhs, assign_tok, rhs, l, c, self.debug)
return EvalStmt(lhs, l, c, self.debug)
raise ParseException("parsing Statement, unkown operators" + str(ptok))
def function(self):
""" def[kw] fname[id] (arglist) {body} end[kw] """
if (self.parsing_function):
raise ParseException(" Nested functions not allowed! ")
self.parsing_function = True
def_tok = self.dequeue()
if (def_tok.kind != Token.DEF):
raise ParseException("unmatched 'def' in function " +
str(def_tok))
id_tok = self.dequeue()
if (id_tok.kind != Token.ID):
raise ParseException("expected identifier in function" +
str(id_tok))
arglist = self.arglist()
self.dbg_msg("finished parsing arglist")
body = self.stmtlist()
self.match(Token.END)
[l, c] = def_tok.get_line_col()
fval = Function(id_tok.val, arglist, body, l, c, self.debug)
self.parsing_function = False
self.dbg_msg("finished parsing function")
return fval
def valuelist(self):
"""parse: ( expr_1 , expr_2, ... ) """
valueList = list()
self.dbg_msg("valuelist: ")
lparen_tok = self.match(Token.LPAREN)
while (self.peek().kind != Token.RPAREN):
val = self.expr()
self.dbg_msg("valuelist-expr: " + str(val))
valueList.append(val)
ptok = self.peek()
if (ptok.kind == Token.RPAREN):
break
elif (ptok.kind == Token.COMMA):
self.match(Token.COMMA)
else:
raise ParseException(" function call argument list " +
str(ptok))
self.match(Token.RPAREN)
[l, c] = lparen_tok.get_line_col()
return ValueList(valueList, l, c, self.debug)
def arglist(self):
"""parse: ( arg_1, arg_2, ... ) """
self.dbg_msg(" ARGLIST ")
args = list()
lparen_tok = self.match(Token.LPAREN)
while (self.peek().kind != Token.RPAREN):
arg_name = self.dequeue()
args.append(arg_name.val)
ptok = self.peek()
if (ptok.kind == Token.RPAREN):
break
elif (ptok.kind == Token.COMMA):
self.match(Token.COMMA)
else:
raise ParseException(" function definition argument list " +
str(ptok))
self.match(Token.RPAREN)
[l, c] = lparen_tok.get_line_col()
return ArgList(args, l, c, self.debug)
def exprlist(self):
""" EXPRLIST : EXPR, EXPRLIST
## EXPRLIST : EXPR """
self.dbg_msg(" EXPRLIST ")
exprs = []
comma_tok = None
l = 0
c = 0
while (not self.lex.end_of_tokens()):
exprs.append(self.expr())
if self.lex.peek().kind != Token.COMMA:
break
tok = self.match(Token.COMMA)
if (not comma_tok):
comma_tok = tok
if (comma_tok):
[l, c] = comma_tok.get_line_col()
self.dbg_msg("finished expression list")
return ExprList(exprs, l, c, self.debug)
def expr(self):
self.dbg_msg(" EXPR ")
val1 = self.term()
res = val1
ptok = self.peek()
if ptok.kind in Token.ADDSUB:
binop = self.dequeue()
val2 = self.expr()
[l, c] = binop.get_line_col()
res = Expr(val1, binop, val2, l, c, self.debug)
elif ptok.kind == Token.LPAREN:
## function call -OR- array type.
if (res.__class__ != Identifier):
raise ParseException("invalid function call" + str(ptok))
[l, c] = ptok.get_line_col()
vallist = self.valuelist()
res = ExprCall(res, vallist, l, c, self.debug)
return res
def term(self):
""" this is a grammar abstraction;
but AST only has Expr elements"""
self.dbg_msg("term")
val1 = self.factor()
res = val1
tok = self.peek()
if (tok.kind in Token.MULDIV or tok.kind in Token.COMPARE
or tok.kind in Token.EXPMOD):
binop = self.dequeue()
val2 = self.expr()
[l, c] = binop.get_line_col()
res = Expr(val1, binop, val2, l, c, self.debug)
return res
def factor(self):
self.dbg_msg("factor")
tok = self.peek()
if tok.kind == Token.LPAREN:
lparen_tok = self.dequeue()
val = self.expr()
if self.dequeue().kind != Token.RPAREN:
raise SyntaxError("Missing Parens")
elif tok.kind == Token.NUMBER:
tok_num = self.dequeue()
[l, c] = tok_num.get_line_col()
val = Number(tok.val, l, c, self.debug)
elif tok.kind == Token.ID:
tok_id = self.dequeue()
[l, c] = tok_id.get_line_col()
val = Identifier(tok.val, l, c, self.debug)
ptok = self.peek()
self.dbg_msg("factor: " + str(ptok) + " / " + str(tok))
if (ptok.kind == Token.LPAREN):
## function call
[l, c] = ptok.get_line_col()
vallist = self.valuelist()
val = ExprCall(val, vallist, l, c, self.debug)
elif (ptok.kind == Token.LSQRBRACE):
## array type
val = None
raise ParseException("arrays not implemented" + str(ptok))
elif tok.kind == Token.STRING:
str_tok = self.dequeue()
[l, c] = str_tok.get_line_col()
val = String(tok.val, l, c, self.debug)
else:
raise ParseException("Expected Number, found something " +
str(tok))
self.dbg_msg("factor-returning: " + str(val))
return val
class EzhilParser(Parser):
""" when you add new language feature, add a AST class
and its evaluate methods. Also add a parser method """
def __init__(self, lexer, fcn_map, builtin_map, dbg=False):
if (not isinstance(lexer, EzhilLex)):
raise RuntimeException("Cannot find Ezhil lexer class")
Parser.__init__(self, lexer, fcn_map, builtin_map, dbg)
def factory(lexer, fcn_map, builtin_map, dbg=False):
""" Factory method """
return EzhilParser(lexer, fcn_map, builtin_map, dbg)
factory = staticmethod(factory)
def match(self, kind):
## if match return token, else ParseException
tok = self.dequeue()
if (tok.kind != kind):
raise ParseException("cannot find token "+ \
EzhilToken.get_name(kind) + " got " \
+ str(tok) \
+ " instead!")
return tok
def parse(self):
""" parser routine """
self.ast = StmtList()
while (not self.lex.end_of_tokens()):
self.dbg_msg("AST length = %d" % len(self.ast))
if (self.lex.peek().kind == EzhilToken.DEF):
self.dbg_msg("parsing for function")
## save function in a global table.
func = self.function()
self.warn_function_overrides(func.name)
self.function_map[func.name] = func
else:
self.dbg_msg("parsing for stmt")
st = self.stmt()
if (not self.parsing_function):
self.ast.append(st)
return self.ast
def stmtlist(self, pass_in_ATexpr=None):
""" parse a bunch of statements """
self.dbg_msg(" STMTLIST ")
stlist = StmtList()
while (not self.lex.end_of_tokens()):
self.dbg_msg("STMTLIST => STMT")
ptok = self.peek()
self.dbg_msg("STMTLIST " + str(ptok))
if (self.debug): print("peek @ ", str(ptok))
if (ptok.kind == EzhilToken.END):
self.dbg_msg("End token found")
break
elif (ptok.kind == EzhilToken.DOWHILE):
if (self.debug): print("DOWHILE token found")
break
elif (self.inside_if
and (ptok.kind == EzhilToken.ELSE or ptok.kind
== EzhilToken.ATRATEOF or ptok.kind == EzhilToken.CASE
or ptok.kind == EzhilToken.OTHERWISE)):
break
st = self.stmt(pass_in_ATexpr)
pass_in_ATexpr = None
stlist.append(st)
return stlist
def parseSwitchStmt(self, exp):
## @ <ID/EXPR> SWITCH @( expr ) CASE {stmtlist} @( expr ) CASE {stmtlist} OTHERWISE {stmtlist} END
## implement as an if-elseif-else statement
self.dbg_msg("parsing SWITCH statement")
sw_tok = self.dequeue()
[l, c] = sw_tok.get_line_col()
self.inside_if = True
lhs = exp[0]
# enter this if-statement always
ifstmt = IfStmt(Number(1), None, None, l, c, self.debug)
self.if_stack.append(ifstmt)
self.dbg_msg("parsing SWITCH-body") #self.dbg_msg
ptok = self.peek()
equality_token = EzhilLexeme("=", EzhilToken.EQUALITY)
while (ptok.kind == EzhilToken.ATRATEOF
or ptok.kind == EzhilToken.OTHERWISE):
self.inside_if = True
[l, c] = ptok.get_line_col()
if (ptok.kind == EzhilToken.ATRATEOF):
# parse elseif branch
self.dbg_msg("parsing CASE")
self.match(EzhilToken.ATRATEOF)
exp = self.valuelist()
self.dbg_msg("parsing CASE EXPR")
self.match(EzhilToken.CASE)
next_stmt = self.stmtlist()
expr = Expr(lhs, equality_token, exp[0], l, c, self.debug)
self.dbg_msg("building an Expr " + str(expr))
if not ifstmt.body:
ifstmt.expr = expr
ifstmt.body = next_stmt
else:
case_stmt = IfStmt(expr, next_stmt, None, l, c, self.debug)
ifstmt.append_stmt(case_stmt)
elif (ptok.kind == EzhilToken.OTHERWISE):
#parse else branch
self.dbg_msg("parsing OTHERWISE: ")
self.match(EzhilToken.OTHERWISE)
self.dbg_msg("parsing OTHERWISE-Body")
self.inside_if = False
body = self.stmtlist()
else_stmt = ElseStmt(body, l, c, self.debug)
if not ifstmt.body:
ifstmt.body = else_stmt
else:
ifstmt.append_stmt(else_stmt)
break
else:
self.inside_if = False
raise ParseError(
"SWITCH-CASE-OTHERWISE statement syntax is messed up")
ptok = self.peek()
self.dbg_msg("parsing SWITCH-CASE next bits " + str(ptok))
self.match(EzhilToken.END)
self.inside_if = False
self.dbg_msg("parsing -SWITCH-CASE- complete")
return ifstmt
def parseIfStmt(self, exp):
## @ <expression> if { stmtlist } @<expr> ELSEIF {stmtlist} ELSE <stmtlist> END
self.dbg_msg("parsing IF statement")
if_tok = self.dequeue()
[l, c] = if_tok.get_line_col()
self.inside_if = True
ifstmt = IfStmt(exp[0], None, None, l, c, self.debug)
self.if_stack.append(ifstmt)
self.dbg_msg("parsing IF-body")
body = self.stmtlist()
prev_body = body
ifstmt.set_body(body)
ptok = self.peek()
while (ptok.kind == EzhilToken.ATRATEOF
or ptok.kind == EzhilToken.ELSE):
self.inside_if = True
[l, c] = ptok.get_line_col()
if (ptok.kind == EzhilToken.ATRATEOF):
# parse elseif branch
self.dbg_msg("parsing ELSE-IF")
self.match(EzhilToken.ATRATEOF)
exp = self.valuelist()
self.dbg_msg("parsing ELSE-IF EXPR")
tok = self.peek()
if (tok.kind != EzhilToken.ELSEIF):
# maybe another IF statement, SWITCH-CASE or a WHILE loop, DO-WHILE loop etc.
next_stmt = self.stmtlist(exp) #pass in the expression
prev_body.append(next_stmt)
# append to previously scanned body.
else:
self.dbg_msg("parsing ELSE-IF-body")
self.match(EzhilToken.ELSEIF)
body = self.stmtlist()
prev_body = body
next_stmt = IfStmt(exp[0], body, None, l, c, self.debug)
ifstmt.append_stmt(next_stmt)
elif (ptok.kind == EzhilToken.ELSE):
#parse else branch
self.dbg_msg("parsing stmt else: ")
self.match(EzhilToken.ELSE)
self.dbg_msg("parsing ELSE-Body")
self.inside_if = False
body = self.stmtlist()
prev_body = body
else_stmt = ElseStmt(body, l, c, self.debug)
ifstmt.append_stmt(else_stmt)
break
else:
self.inside_if = False
raise ParseError("If-Else-If statement syntax is messed up")
ptok = self.peek()
self.dbg_msg("parsing -IF next bits " + str(ptok))
self.match(EzhilToken.END)
self.inside_if = False
self.dbg_msg("parsing -IF-complete")
return ifstmt
def stmt(self, pass_in_ATexpr=None):
""" try an assign, print, return, if or eval statement """
self.dbg_msg(" STMT ")
ptok = self.peek()
self.dbg_msg("stmt: peeking at " + str(ptok))
if (ptok.kind == EzhilToken.RETURN):
## return <expression>
self.dbg_msg('enter->return: <expression>')
ret_tok = self.dequeue()
[l, c] = ret_tok.get_line_col()
rstmt = ReturnStmt(self.expr(), l, c, self.debug)
self.dbg_msg("return statement parsed")
return rstmt
elif (ptok.kind == EzhilToken.PRINT):
self.currently_parsing.append(ptok)
## print <expression>
print_tok = self.dequeue()
[l, c] = print_tok.get_line_col()
exprlist_val = self.exprlist()
self.currently_parsing.pop()
return PrintStmt(exprlist_val, l, c, self.debug)
elif (ptok.kind == EzhilToken.ATRATEOF or pass_in_ATexpr):
## @ <expression> {if | while | elseif}
if not pass_in_ATexpr:
at_tok = self.match(EzhilToken.ATRATEOF)
self.currently_parsing.append(at_tok)
exp = self.valuelist()
self.currently_parsing.pop()
else:
exp = pass_in_ATexpr
if (self.debug): print("return from valuelist ", str(exp))
ptok = self.peek()
if (ptok.kind == EzhilToken.IF):
return self.parseIfStmt(exp)
elif (ptok.kind == EzhilToken.WHILE):
## @ ( expr ) while { body } end
self.loop_stack.append(True)
self.dbg_msg("while-statement")
while_tok = self.dequeue()
self.currently_parsing.append(while_tok)
[l, c] = while_tok.get_line_col()
wexpr = exp[0]
body = self.stmtlist()
self.match(EzhilToken.END)
whilestmt = WhileStmt(wexpr, body, l, c, self.debug)
self.loop_stack.pop()
self.currently_parsing.pop()
return whilestmt
elif (ptok.kind == EzhilToken.SWITCH):
return self.parseSwitchStmt(exp)
elif (ptok.kind == EzhilToken.FOREACH):
foreach_tok = self.dequeue()
self.currently_parsing.append(foreach_tok)
[l, c] = foreach_tok.get_line_col()
if (self.debug): print("parsing FOREACH stmt")
self.loop_stack.append(True)
self.dbg_msg("foreach-statement")
# convert to a for statement - building Ezhil AST - transformations
if not isinstance(exp[1], Identifier):
raise ParseError(" FOR-EACH statement " + str(foreach_tok))
foreach_iter = exp[1]
iter = Identifier("__" + foreach_iter.id, l=0, c=-1)
eq_token = EzhilLexeme("=", EzhilToken.EQUALS)
plus_token = EzhilLexeme("+", EzhilToken.PLUS)
lt_token = EzhilLexeme("<", EzhilToken.LT)
if (self.debug): print("build init assign stmt")
init = AssignStmt(iter, eq_token, Number(0), l, c, self.debug)
if (self.debug): print("build cond expr")
VL1 = ValueList([exp[0]], l, c, self.debug)
cond = Expr(
iter, lt_token,
ExprCall(Identifier("len", l, c), VL1, l, c, self.debug),
l, c, self.debug)
if (self.debug): print("build plus1 stmt")
plus1_iter = Expr(iter, plus_token, Number(1), l, c,
self.debug)
if (self.debug): print("build equals stmt")
update = AssignStmt(iter, eq_token, plus1_iter, l, c,
self.debug)
body = self.stmtlist() #parse body
# and insert artifical update variable in body
VL2 = ValueList([exp[0], iter], l, c, self.debug)
extract_foreach_iter_from_list = ExprCall(
Identifier("__getitem__", l, c), VL2, l, c, self.debug)
foreach_iter_Assign = AssignStmt(
foreach_iter, eq_token, extract_foreach_iter_from_list, l,
c, self.debug)
body.List.insert(0, foreach_iter_Assign)
# complete FOREACH stmt
self.match(EzhilToken.END)
self.currently_parsing.pop()
foreach_stmt = ForStmt(init, cond, update, body, l, c,
self.debug)
self.loop_stack.pop()
if (self.debug):
print("completed parsing FOR-EACH loop", str(foreach_stmt))
return foreach_stmt
elif (ptok.kind == EzhilToken.FOR):
## Fixme : empty for loops not allowed.
""" For ( exp1 , exp2 , exp3 ) stmtlist end"""
if (self.debug): print("parsing FOR stmt")
self.loop_stack.append(True)
self.dbg_msg("for-statement")
for_tok = self.peek()
self.currently_parsing.append(for_tok)
if (self.debug): print("matching for STMT", str(self.peek()))
self.match(EzhilToken.FOR)
if (self.debug): print("matched for STMT", str(self.peek()))
[l, c] = for_tok.get_line_col()
init, cond, update = exp[0], exp[1], exp[2]
if (self.debug):
print("extract 3 parts", str(init), str(cond), str(update))
body = self.stmtlist()
self.match(EzhilToken.END)
self.currently_parsing.pop()
if (self.debug): print("body of loop", str(body))
forstmt = ForStmt(init, cond, update, body, l, c, self.debug)
self.loop_stack.pop()
if (self.debug):
print("completed parsing FOR loop", str(forstmt))
return forstmt
elif (ptok.kind == EzhilToken.DO):
if (self.debug): print("parsing DO-WHILE statement")
self.loop_stack.append(True)
do_tok = self.dequeue()
self.currently_parsing.append(do_tok)
[l, c] = do_tok.get_line_col()
body = self.stmtlist()
if (self.debug): print("parsed body")
self.match(EzhilToken.DOWHILE)
self.match(EzhilToken.ATRATEOF)
exp = self.valuelist()
if (self.debug): print("parsed EXP", exp[0])
doWhileStmt = DoWhileStmt(exp[0], body, l, c, self.debug)
self.loop_stack.pop()
self.currently_parsing.pop()
return doWhileStmt
elif (ptok.kind == EzhilToken.BREAK):
## break, must be in loop-environment
self.dbg_msg("break-statement")
break_tok = self.dequeue()
[l, c] = break_tok.get_line_col()
self.check_loop_stack()
##raises a parse error
brkstmt = BreakStmt(l, c, self.debug)
return brkstmt
elif (ptok.kind == EzhilToken.CONTINUE):
## continue, must be in loop-environment
self.dbg_msg("continue-statement")
cont_tok = self.dequeue()
[l, c] = cont_tok.get_line_col()
self.check_loop_stack()
##raises a parse error
cntstmt = ContinueStmt(l, c, self.debug)
return cntstmt
else:
## lval := rval
ptok = self.peek()
self.currently_parsing.append(ptok)
[l, c] = ptok.get_line_col()
lhs = self.expr()
self.dbg_msg("parsing expr: " + str(lhs))
ptok = self.peek()
if (ptok.kind in EzhilToken.ASSIGNOP):
assign_tok = self.dequeue()
rhs = self.expr()
[l, c] = assign_tok.get_line_col()
self.currently_parsing.pop()
return AssignStmt(lhs, assign_tok, rhs, l, c, self.debug)
self.currently_parsing.pop()
return EvalStmt(lhs, l, c, self.debug)
raise ParseException("parsing Statement, unkown operators" + str(ptok))
def function(self):
""" def[kw] fname[id] (arglist) {body} end[kw] """
if (self.parsing_function):
self.parsing_function = False
raise ParseException(" Nested functions not allowed! " +
str(self.last_token()))
self.parsing_function = True
def_tok = self.dequeue()
if (def_tok.kind != EzhilToken.DEF):
raise ParseException("unmatched 'def' in function " +
str(def_tok))
id_tok = self.dequeue()
if (id_tok.kind != EzhilToken.ID):
raise ParseException("expected identifier in function" +
str(id_tok))
arglist = self.arglist()
self.dbg_msg("finished parsing arglist")
body = self.stmtlist()
self.match(EzhilToken.END)
[l, c] = def_tok.get_line_col()
fval = Function(id_tok.val, arglist, body, l, c, self.debug)
self.parsing_function = False
self.dbg_msg("finished parsing function")
return fval
def valuelist(self):
"""parse: ( expr_1 , expr_2, ... ) """
valueList = list()
self.dbg_msg("valuelist: ")
lparen_tok = self.match(EzhilToken.LPAREN)
while (self.peek().kind != EzhilToken.RPAREN):
val = self.expr()
if (self.debug): print("val = ", str(val))
ptok = self.peek()
if (self.debug):
print("ptok = ", str(ptok), str(ptok.kind),
str(EzhilToken.ASSIGNOP))
if (ptok.kind in EzhilToken.ASSIGNOP):
assign_tok = self.dequeue()
rhs = self.expr()
[l, c] = assign_tok.get_line_col()
lhs = val
val = AssignStmt(lhs, assign_tok, rhs, l, c, self.debug)
if (self.debug): print("AssignStmt = ", str(val))
ptok = self.peek()
else:
if (self.debug): print("No-Assign // Expr =", str(val))
self.dbg_msg("valuelist-expr: " + str(val))
valueList.append(val)
if (ptok.kind == EzhilToken.RPAREN):
break
elif (ptok.kind == EzhilToken.COMMA):
self.match(EzhilToken.COMMA)
else:
raise ParseException(" function call argument list " +
str(ptok))
self.match(EzhilToken.RPAREN)
[l, c] = lparen_tok.get_line_col()
return ValueList(valueList, l, c, self.debug)
def arglist(self):
"""parse: ( arg_1, arg_2, ... ) """
self.dbg_msg(" ARGLIST ")
args = list()
lparen_tok = self.match(EzhilToken.LPAREN)
while (self.peek().kind != EzhilToken.RPAREN):
arg_name = self.dequeue()
args.append(arg_name.val)
ptok = self.peek()
if (ptok.kind == EzhilToken.RPAREN):
break
elif (ptok.kind == EzhilToken.COMMA):
self.match(EzhilToken.COMMA)
else:
raise ParseException(" function definition argument list " +
str(ptok))
self.match(EzhilToken.RPAREN)
[l, c] = lparen_tok.get_line_col()
return ArgList(args, l, c, self.debug)
def exprlist(self):
""" EXPRLIST : EXPR, EXPRLIST
## EXPRLIST : EXPR """
self.dbg_msg(" EXPRLIST ")
exprs = []
comma_tok = None
l = 0
c = 0
while (not self.lex.end_of_tokens()):
exprs.append(self.expr())
if self.lex.peek().kind != EzhilToken.COMMA:
break
tok = self.match(EzhilToken.COMMA)
if (not comma_tok):
comma_tok = tok
if (comma_tok):
[l, c] = comma_tok.get_line_col()
self.dbg_msg("finished expression list")
return ExprList(exprs, l, c, self.debug)
def expr(self):
self.dbg_msg(" EXPR ")
val1 = self.term()
res = val1
ptok = self.peek()
if ptok.kind in EzhilToken.ADDSUB:
binop = self.dequeue()
if (ptok.kind == EzhilToken.MINUS):
val2 = self.term()
else:
val2 = self.expr()
[l, c] = binop.get_line_col()
res = Expr(val1, binop, val2, l, c, self.debug)
elif ptok.kind == EzhilToken.LPAREN:
## function call
if (res.__class__ != Identifier):
raise ParseException("invalid function call" + str(ptok))
[l, c] = ptok.get_line_col()
vallist = self.valuelist()
res = ExprCall(res, vallist, l, c, self.debug)
ptok = self.peek()
while ptok.kind in EzhilToken.BINOP:
binop = self.dequeue()
[l, c] = binop.get_line_col()
res = Expr(res, binop, self.expr(), l, c, self.debug)
ptok = self.peek()
return res
def term(self):
""" this is a grammar abstraction;
but AST only has Expr elements"""
self.dbg_msg("term")
val1 = self.factor()
res = val1
tok = self.peek()
if (tok.kind in EzhilToken.MULDIV or tok.kind in EzhilToken.COMPARE
or tok.kind in EzhilToken.EXPMOD
or tok.kind in EzhilToken.BITWISE_AND_LOGICAL):
binop = self.dequeue()
val2 = self.term()
[l, c] = binop.get_line_col()
res = Expr(val1, binop, val2, l, c, self.debug)
return res
def factor(self):
self.dbg_msg("factor")
tok = self.peek()
if tok.kind == EzhilToken.LPAREN:
lparen_tok = self.dequeue()
val = self.expr()
if self.dequeue().kind != EzhilToken.RPAREN:
raise SyntaxError("Missing Parens " + str(self.last_token()))
elif tok.kind == EzhilToken.NUMBER:
tok_num = self.dequeue()
[l, c] = tok_num.get_line_col()
val = Number(tok.val, l, c, self.debug)
elif tok.kind == EzhilToken.LOGICAL_NOT:
tok_not = self.dequeue()
[l, c] = tok_not.get_line_col()
val = UnaryExpr(self.expr(), tok_not, l, c, self.debug)
self.dbg_msg("completed parsing unary expression" + str(val))
elif tok.kind == EzhilToken.ID:
tok_id = self.dequeue()
[l, c] = tok_id.get_line_col()
val = Identifier(tok.val, l, c, self.debug)
ptok = self.peek()
self.dbg_msg("factor: " + str(ptok) + " / " + str(tok))
if (ptok.kind == EzhilToken.LPAREN):
## function call
[l, c] = ptok.get_line_col()
vallist = self.valuelist()
val = ExprCall(val, vallist, l, c, self.debug)
elif (ptok.kind == EzhilToken.LSQRBRACE):
## indexing a array type variable or ID
val = None
raise ParseException("arrays not implemented" + str(ptok))
elif tok.kind == EzhilToken.STRING:
str_tok = self.dequeue()
[l, c] = str_tok.get_line_col()
val = String(tok.val, l, c, self.debug)
elif tok.kind in EzhilToken.ADDSUB:
unop = self.dequeue()
[l, c] = unop.get_line_col()
val = Expr(Number(0), unop, self.term(), l, c, self.debug)
elif tok.kind == EzhilToken.LSQRBRACE:
# creating a list/array expression
list_start = self.dequeue()
val = Array()
while (True):
exprval = self.expr()
val.append(exprval)
if self.debug: print(self.peek().__class__, self.peek())
if (self.peek().kind == EzhilToken.RSQRBRACE):
break
else:
assert (self.peek().kind == EzhilToken.COMMA)
self.dequeue()
assert (self.peek().kind == EzhilToken.RSQRBRACE)
list_end = self.dequeue()
else:
raise ParseException("Expected Number, found something " +
str(tok))
self.dbg_msg("factor-returning: " + str(val))
return val
