fix function_call

- function_call is now an expression and a statement
- call keyword is required to make lookahead = 1 work

6 files changed, 59 insertions, 102 deletions

diff --git a/doc/mylang.ebnf b/doc/mylang.ebnf
index 7c67bbb..f84869f 100644
--- a/doc/mylang.ebnf
+++ b/doc/mylang.ebnf
@@ -8,27 +8,27 @@ nl = "\n".
 ident = letter { letter | digit }.
 integer = digit { digit }.
 
-disjunction = conjunction { "||" conjunction }.
-conjunction = boolean { "&&" boolean }.
-boolean = "!" disjunction | comparison | "(" disjunction ")" | "true" | "false".
-comparison = expression ( "==" | "!=" | "<" | "<=" | "=>" | ">" ) expression.
-
+boolean = join { "||" join }.
+join = relation { "&&" relation }.
+relation = expression { ( "==" | "!=" | "<" | "<=" | ">=" | ">" ) expression }.
 expression = term { ( "+" | "-" ) term }.
 term = unary { ( "*" | "/" | "%" ) unary }.
-unary = ident | integer | "-" unary | "(" expression ")".
+unary = "!" unary | "-" unary | factor.
+factor = "(" boolean ")" | ident | integer | "true" | "false" | function_call.
+
+function_call = "call" ident "[" [ expression_list ] "]".
 
 ident_list = ident { "," ident }.
-expression_list = expression { "," expression }.
-function_list = function { nl function }.
-statement_list = statement { nl statement }.
-
-function = "fun" ident "[" [ ident_list ] "]" nl statement_list nl "end".
-statement = [ if_statement | while_statement | assign_statement | function_call | return_statement ].
-
-if_statement = "if" expression nl statement_list nl [ "else" statement_list nl ] "end".
-while_statement = "while" expression nl statement_list nl "end".
-return_statement = "@" expression.
-assign_statement = ident "=" expression.
-function_call = ident "[" [ expression_list ] "]".
+expression_list = boolean { "," boolean }.
+function_list = function { function }.
+statement_list = statement { statement }.
+
+function = "fun" ident "[" [ ident_list ] "]" nl statement_list "end" nl.
+statement = ( if_statement | while_statement | assign_statement | return_statement | function_call ).
+
+if_statement = "if" boolean nl statement_list [ "else" nl statement_list ] "end" nl.
+while_statement = "while" boolean nl statement_list "end" nl.
+return_statement = "@" boolean nl.
+assign_statement = ident "=" boolean nl.
 
 program = function_list.
diff --git a/src/__init__.py b/src/__init__.py
index 747efde..ad0278b 100644
--- a/src/__init__.py
+++ b/src/__init__.py
@@ -1,13 +1,12 @@
 from front.lexer import Lexer
 from front.parser import Parser
-#from front.symbols import SymbolTable
 
 def main():
     source = '''fun fib[a]
 	if a < 2
 		@1
 	end
-	@( fib[a-1] + fib[a-2] )
+	@( call fib[a-1] + call fib[a-2] )
 end
 
 # main function
@@ -15,24 +14,13 @@ fun main[]
 	sum = 0
 	i = 0
 	while (i < 10)
-		sum = sum + fib[i]
+		sum = sum + call fib[i]
 		i = i + 1
 	end
 	@sum
 end'''
 
-    #symbols = SymbolTable()
-    #lex = Lexer(source)
-
-    # testing
-    #while True:
-    #    token = lex.scan()
-    #    print token.__repr__()
-    #    if not token:
-    #        break
-
-    parse = Parser(Lexer(source))
-    print parse.parse()
+    print Parser(Lexer(source)).parse()
 
 if __name__ == "__main__":
     main()
diff --git a/src/front/ast.py b/src/front/ast.py
index 751d38d..d6d4a3f 100644
--- a/src/front/ast.py
+++ b/src/front/ast.py
@@ -25,7 +25,7 @@ class Function(Node):
         self.lineno = lineno
 
     def __repr__(self):
-        return "<Function: %s %s %s>" % (self.name, str(self.params), str(self.statements))
+        return "<Function: %s(%s) at line %d: %s>" % (self.name, str(self.params), self.lineno, str(self.statements))
 
     def eval(self,tacarray):
         return tacarray.append(te)
diff --git a/src/front/lexer.py b/src/front/lexer.py
index f2810cd..53ccaec 100644
--- a/src/front/lexer.py
+++ b/src/front/lexer.py
@@ -21,6 +21,7 @@ class Lexer:
                               'while': Token(Tag.WHILE),
                               'if': Token(Tag.IF),
                               'else': Token(Tag.ELSE),
+                              'call': Token(Tag.CALL),
                               'fun': Token(Tag.FUN),
                               'end': Token(Tag.END)}
         return
diff --git a/src/front/parser.py b/src/front/parser.py
index 29e300d..610a5bb 100644
--- a/src/front/parser.py
+++ b/src/front/parser.py
@@ -36,58 +36,41 @@ class Parser:
     def boolean(self):
         res = self.join()
         while self.token.tag == Tag.OPERATOR and self.token.value == "||":
-            self.move()
-            res = BinaryExpression(res, "||", self.join())
+            res = BinaryExpression(res, self.match(Tag.OPERATOR), self.join(), self.lexer.line)
         return res
 
-    # join = equality { "&&" equality }.
+    # join = relation { "&&" relation }.
     def join(self):
-        res = self.equality()
-        while self.token.tag == Tag.OPERATOR and self.token.value == "&&":
-            self.move()
-            res = BinaryExpression(res, "&&", self.relation())
-        return res
-
-    # equality = relation { ( "==" | "!=" ) relation }.
-    def equality(self):
         res = self.relation()
-        while self.token.tag == Tag.OPERATOR and self.token.value in ["==", "!="]:
-            op = self.match(Tag.OPERATOR)
-            res = BinaryExpression(res, op, self.relation())
+        while self.token.tag == Tag.OPERATOR and self.token.value == "&&":
+            res = BinaryExpression(res, self.match(Tag.OPERATOR), self.relation(), self.lexer.line)
         return res
 
-    # relation = expression { ( "<" | "<=" | ">=" | ">" ) expression }.
+    # relation = expression { ( "==" | "!=" | "<" | "<=" | ">=" | ">" ) expression }.
     def relation(self):
         res = self.expression()
-        while self.token.tag == Tag.OPERATOR and self.token.value in ["<", "<=", ">=", ">"]:
-            op = self.match(Tag.OPERATOR)
-            res = BinaryExpression(res, op, self.expression())
+        while self.token.tag == Tag.OPERATOR and self.token.value in ["==", "!=", "<", "<=", ">=", ">"]:
+            res = BinaryExpression(res, self.match(Tag.OPERATOR), self.expression(), self.lexer.line)
         return res
 
     # expression = term { ( "+" | "-" ) term }.
     def expression(self):
         res = self.term()
         while self.token.tag == Tag.OPERATOR and self.token.value in ["+", "-"]:
-            op = self.match(Tag.OPERATOR)
-            res = BinaryExpression(res, op, self.term())
+            res = BinaryExpression(res, self.match(Tag.OPERATOR), self.term(), self.lexer.line)
         return res
 
     # term = unary { ( "*" | "/" | "%" ) unary }.
     def term(self):
         res = self.unary()
         while self.token.tag == Tag.OPERATOR and self.token.value in ["*", "/", "%"]:
-            op = self.match(Tag.OPERATOR)
-            res = BinaryExpression(res, op, self.unary())
+            res = BinaryExpression(res, self.match(Tag.OPERATOR), self.unary(), self.lexer.line)
         return res
 
     # unary = "!" unary | "-" unary | factor.
     def unary(self):
-        if self.token.tag == Tag.OPERATOR and self.token.value == "!":
-            self.move()
-            return UnaryExpression("!", self.unary())
-        if self.token.tag == Tag.OPERATOR and self.token.value == "-":
-            self.move()
-            return UnaryExpression("-", self.unary())
+        if self.token.tag == Tag.OPERATOR and self.token.value in ["!", "-"]:
+            return UnaryExpression(self.match(Tag.OPERATOR), self.unary(), self.lexer.line)
         return self.factor()
 
     # factor = "(" boolean ")" | integer | "true" | "false" | ident | function_call.
@@ -98,46 +81,25 @@ class Parser:
             self.match(Tag.RPAREN)
             return res
         if self.token.tag == Tag.NUMBER:
-            return Constant(self.match(Tag.NUMBER))
+            return Constant(self.match(Tag.NUMBER), self.lexer.line)
         if self.token.tag == Tag.TRUE:
             self.move()
-            return Constant(1)
+            return Constant(1, self.lexer.line)
         if self.token.tag == Tag.FALSE:
             self.move()
-            return Constant(0)
-        ''' Wegen der Änderung in function_call() kann die Grammatik nicht
-            mehr mit einem Lookahead von 1 geparst werden. Die Lösung hier
-            ist, den Aufruf von function_call() zu "inlinen". Muss irgendwann
-            aber geändert werden. Eine Lösung wäre Funktionen mit call
-            aufzurufen oder eben auf LL(2) oder LR umzusteigen.
-        '''
+            return Constant(0, self.lexer.line)
         if self.token.tag == Tag.IDENT:
-            name = self.match(Tag.IDENT)
-            if self.token.tag == Tag.LBRAK: # function_call
-                self.match(Tag.LBRAK)
-                args = [] if self.token.tag == Tag.RBRAK else self.expression_list()
-                self.match(Tag.RBRAK)
-                return FunctionCall(name, args)
-            return Variable(name)# variable
-
-        error("unknown factor begins with " + self.token.tag)
-
-    # function_call = ident "[" [ expression_list ] "]".
-    ''' function_call muss eine expression sein sonst geht alles folgende nicht:
-            foo = bar[]
-            @foo[bar]
-            spam[5] + eggs[1]
-        andererseits ist function_call dann kein statement mehr
-            exit[]
-        wäre also falsch. Der Aufruf muss in einem assignment verkapselt werden:
-            dummy = exit[]
-    '''
+            return Variable(self.match(Tag.IDENT), self.lexer.line)
+        return self.function_call()
+
+    # function_call = "call" ident "[" [ expression_list ] "]".
     def function_call(self):
+        self.match(Tag.CALL)
         name = self.match(Tag.IDENT)
         self.match(Tag.LBRAK)
         args = [] if self.token.tag == Tag.RBRAK else self.expression_list()
         self.match(Tag.RBRAK)
-        return FunctionCall(name, args)
+        return FunctionCall(name, args, self.lexer.line)
 
     # ident_list = ident { "," ident }.
     def ident_list(self):
@@ -171,6 +133,7 @@ class Parser:
 
     # function = "fun" ident "[" [ ident_list ] "]" nl statement_list "end" nl.
     def function(self):
+        line = self.lexer.line
         self.match(Tag.FUN)
         name = self.match(Tag.IDENT)
         self.match(Tag.LBRAK)
@@ -180,18 +143,20 @@ class Parser:
         block = self.statement_list()
         self.match(Tag.END)
         self.match(Tag.NEWLINE)
-        return Function(name, args, block)
+        return Function(name, args, block, line)
 
-    # statement = [ if_statement | while_statement | assign_statement | return_statement ].
+    # statement = [ if_statement | while_statement | assign_statement | return_statement | function_call ].
     def statement(self):
         return {Tag.IF:         self.if_statement,
                 Tag.WHILE:      self.while_statement,
                 Tag.IDENT:      self.assignment,
-                Tag.RETURN:     self.return_statement
+                Tag.RETURN:     self.return_statement,
+                Tag.CALL:       self.function_call,
                 }[self.token.tag]()
 
-    # if_statement = "if" boolean nl statement_list [ "else" [ nl ] statement_list ] "end" nl.
+    # if_statement = "if" boolean nl statement_list [ "else" nl statement_list ] "end" nl.
     def if_statement(self):
+        line = self.lexer.line
         self.match(Tag.IF)
         condition = self.boolean()
         self.match(Tag.NEWLINE)
@@ -199,38 +164,40 @@ class Parser:
         else_case = []
         if self.token.tag == Tag.ELSE:
             self.move()
-            if self.token.tag == Tag.NEWLINE: self.move()
+            self.match(Tag.NEWLINE)
             else_case = self.statement_list()
         self.match(Tag.END)
         self.match(Tag.NEWLINE)
-        return IfStatement(condition, true_case, else_case)
+        return IfStatement(condition, true_case, else_case, line)
 
     # while_statement = "while" boolean nl statement_list "end" nl.
     def while_statement(self):
+        line = self.lexer.line
         self.match(Tag.WHILE)
         condition = self.boolean()
         self.match(Tag.NEWLINE)
         body = self.statement_list()
         self.match(Tag.END)
         self.match(Tag.NEWLINE)
-        return WhileStatement(condition, body)
+        return WhileStatement(condition, body, line)
 
     # return_statement = "@" boolean nl.
     def return_statement(self):
+        line = self.lexer.line
         self.match(Tag.RETURN)
         exp = self.boolean()
         self.match(Tag.NEWLINE)
-        return ReturnStatement(exp)
+        return ReturnStatement(exp, line)
 
     # assignment = ident "=" boolean nl.
     def assignment(self):
+        line = self.lexer.line
         name = self.match(Tag.IDENT)
         self.match(Tag.ASSIGNMENT)
         exp = self.boolean()
         self.match(Tag.NEWLINE)
-        return AssignStatement(name, exp)
+        return AssignStatement(name, exp, line)
 
     # program = function_list.
     def program(self):
         return Program(self.function_list())
-
diff --git a/src/front/token.py b/src/front/token.py
index bfcc082..78e9dab 100644
--- a/src/front/token.py
+++ b/src/front/token.py
@@ -27,6 +27,7 @@ Tag.RPAREN      = Tag("RPAREN")
 Tag.NEWLINE     = Tag("NEWLINE")
 Tag.COMMA       = Tag("COMMA")
 Tag.FUN         = Tag("FUN")
+Tag.CALL        = Tag("CALL")
 Tag.ASSIGNMENT  = Tag("ASSIGNMENT")
 Tag.RETURN      = Tag("RETURN")
 Tag.OPERATOR    = Tag("OPERATOR")