added syntax field array attribute

code/code_gen/code_gen.py

@@ -20,10 +20,15 @@ calc_grammar = """
 
     ?start: statement*
 
-    ?statement: NAME "=" sum -> assign_var
+    ?statement: NAME [ "(" [attr_list] ")" ] "=" sum -> assign_var
               | avg "{" [NAME ("," NAME)*] "}" -> assign_avg_var
               | varlist
 
+    ?attr_list: attr_pair ("," attr_pair)*
+
+    ?attr_pair: NAME "=" NAME
+              | NAME "=" INT
+
     ?sum: product
         | sum "+" product   -> add
         | sum "-" product   -> sub
@@ -63,6 +68,7 @@ calc_grammar = """
 
     %import common.CNAME -> NAME
     %import common.NUMBER
+    %import common.INT
     %import common.WS
 
     COMMENT: /#.*/
@@ -71,6 +77,10 @@ calc_grammar = """
     %ignore WS
 """
 
+def tok_to_int(tok):
+    "Convert the value of `tok` from string to int, while maintaining line number & column."
+    # tok.type == 'INT'
+    return Token.new_borrow_pos(tok.type, int(tok), tok)
 
 class VersionInfo(object):
 
@@ -112,7 +122,7 @@ class VersionInfo(object):
 
 def test(terms_raw, report=False):
 
-    tree = Lark(calc_grammar, parser='lalr' ).parse(terms_raw)
+    tree = Lark(calc_grammar, parser='lalr', lexer_callbacks = {'INT': tok_to_int}).parse(terms_raw)
 
     ir1 = Stage1(tree)
 

code/code_gen/post.py

@@ -14,11 +14,22 @@ class CollectDefinitions(Visitor):
             self.derived[v.value] = PrimaryField(v.value, self.derived)
 
     def assign_var (self, tree):
-        lval, rval = tree.children
+        if len(tree.children) > 2:
+            lval, lattr, rval = tree.children
+        else:
+            lval, rval = tree.children
+            lattr = None
+
+        attr_dict = {}
+
+        if lattr is not None:
+            for t in lattr.children:
+                k, v = t.children
+                attr_dict[k.value] = v.value
 
         if lval.value in self.derived:
             raise StandardError("duplicate definition of " + lval)
-        self.derived[lval.value] = Field(lval.value, rval, self.derived)
+        self.derived[lval.value] = Field(lval.value, attr_dict, rval, self.derived)
 
     def assign_avg_var (self, tree):
         w = tree.children[0]
@@ -205,8 +216,9 @@ class FieldBase (object):
 
 class Field (FieldBase):
 
-    def __init__ (self, name, exp, fdict):
+    def __init__ (self, name, attr, exp, fdict):
         super(Field,self).__init__(name, fdict)
+        self.attr = attr
         self.exp = exp
         self.fluc, self.dep, self.derivs = ExpInspector.inspect(exp)
         self.comment = ExpToCode(self.fdict).transform(self.exp)

code/code_gen/terms.input

@@ -4,12 +4,12 @@
 
 c = 1.0 - y
 
-fsd = sqrt (sqr(ddx(c)) + sqr(ddy(c)) + sqr(ddz(c)))
+fsd () = sqrt (sqr(ddx(c)) + sqr(ddy(c)) + sqr(ddz(c)))
 
 nx = - ddx(c) / fsd
 ny = - ddy(c) / fsd
 nz = - ddz(c) / fsd
 
-divn = ddx(nx) + ddy(ny) + ddz(nz)
+divn (a=1, b=kill, xlow=128, xupp=320) = ddx(nx) + ddy(ny) + ddz(nz)
 
 avg { c, fsd, divn }