fix function call as statement, fix EBNF errors

3 files changed, 23 insertions, 26 deletions

diff --git a/doc/mylang.ebnf b/doc/mylang.ebnf
index f84869f..04db743 100644
--- a/doc/mylang.ebnf
+++ b/doc/mylang.ebnf
@@ -10,25 +10,24 @@ integer = digit { digit }.
 
 boolean = join { "||" join }.
 join = relation { "&&" relation }.
-relation = expression { ( "==" | "!=" | "<" | "<=" | ">=" | ">" ) expression }.
-expression = term { ( "+" | "-" ) term }.
-term = unary { ( "*" | "/" | "%" ) unary }.
+relation = expression [ ( "==" | "!=" | "<" | "<=" | ">=" | ">" ) expression ].
+expression = term [ ( "+" | "-" ) term ].
+term = unary [ ( "*" | "/" | "%" ) unary ].
 unary = "!" unary | "-" unary | factor.
 factor = "(" boolean ")" | ident | integer | "true" | "false" | function_call.
 
-function_call = "call" ident "[" [ expression_list ] "]".
-
 ident_list = ident { "," ident }.
 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 ).
+statement = ( if_statement | while_statement | assign_statement | return_statement | function_call ) nl.
 
-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.
+if_statement = "if" boolean nl statement_list [ "else" nl statement_list ] "end".
+while_statement = "while" boolean nl statement_list "end".
+return_statement = "@" boolean.
+assign_statement = ident "=" boolean.
+function_call = "call" ident "[" [ expression_list ] "]".
 
 program = function_list.
diff --git a/src/front/ast.py b/src/front/ast.py
index 875bdf0..77aab95 100644
--- a/src/front/ast.py
+++ b/src/front/ast.py
@@ -178,8 +178,7 @@ class FunctionCall(Statement, Expression):
         for argument in self.arguments:
             self.emit(Op.POP, 0)
 
-    # XXX: wrong signature?
-    def generate(self):
+    def generate(self, before, after, last):
         self.debug("FunctionCall.generate(): %s" % (repr(self)))
         self.push_params()
         self.emit(Op.CALL, self.ident, 0)
diff --git a/src/front/parser.py b/src/front/parser.py
index 8eca7a2..72e0051 100644
--- a/src/front/parser.py
+++ b/src/front/parser.py
@@ -17,7 +17,6 @@ class Parser:
 
     def move(self):
         self.token = self.lexer.scan()
-        #print "move(): %s" % self.token
 
     def error(self, msg):
         raise ParseError(msg)
@@ -50,21 +49,21 @@ class Parser:
             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 ["==", "!=", "<", "<=", ">=", ">"]:
             res = BinaryExpression(res, self.match(Tag.OPERATOR), self.expression(), self.lexer.line)
         return res
 
-    # expression = term { ( "+" | "-" ) term }.
+    # expression = term [ ( "+" | "-" ) term ].
     def expression(self):
         res = self.term()
         while self.token.tag == Tag.OPERATOR and self.token.value in ["+", "-"]:
             res = BinaryExpression(res, self.match(Tag.OPERATOR), self.term(), self.lexer.line)
         return res
 
-    # term = unary { ( "*" | "/" | "%" ) unary }.
+    # term = unary [ ( "*" | "/" | "%" ) unary ].
     def term(self):
         res = self.unary()
         while self.token.tag == Tag.OPERATOR and self.token.value in ["*", "/", "%"]:
@@ -150,16 +149,18 @@ class Parser:
         self.match(Tag.END, Tag.NEWLINE)
         return Function(name, args, block, line)
 
-    # statement = [ if_statement | while_statement | assign_statement | return_statement | function_call ].
+    # statement = ( if_statement | while_statement | assign_statement | return_statement | function_call ) nl.
     def statement(self):
-        return {Tag.IF:         self.if_statement,
+        res =  {Tag.IF:         self.if_statement,
                 Tag.WHILE:      self.while_statement,
                 Tag.IDENT:      self.assignment,
                 Tag.RETURN:     self.return_statement,
                 Tag.CALL:       self.function_call,
                 }[self.token.tag]()
+        self.match(Tag.NEWLINE)
+        return res
 
-    # 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".
     def if_statement(self):
         line = self.lexer.line
         self.match(Tag.IF)
@@ -171,34 +172,32 @@ class Parser:
             self.move()
             self.match(Tag.NEWLINE)
             else_case = self.statement_list()
-        self.match(Tag.END, Tag.NEWLINE)
+        self.match(Tag.END)
         return IfStatement(condition, true_case, else_case, line)
 
-    # while_statement = "while" boolean nl statement_list "end" nl.
+    # while_statement = "while" boolean nl statement_list "end".
     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, Tag.NEWLINE)
+        self.match(Tag.END)
         return WhileStatement(condition, body, line)
 
-    # return_statement = "@" boolean nl.
+    # return_statement = "@" boolean.
     def return_statement(self):
         line = self.lexer.line
         self.match(Tag.RETURN)
         exp = self.boolean()
-        self.match(Tag.NEWLINE)
         return ReturnStatement(exp, line)
 
-    # assignment = ident "=" boolean nl.
+    # assignment = ident "=" boolean.
     def assignment(self):
         line = self.lexer.line
         name = self.match(Tag.IDENT)
         self.match(Tag.ASSIGNMENT)
         exp = self.boolean()
-        self.match(Tag.NEWLINE)
         self.scope.add_locals(name)
         return AssignStatement(name, exp, line)