grammar,astgen: parse enum literal (.enum_field)

bsc/AST.py

@@ -258,6 +258,17 @@ def __str__(self):
     def __repr__(self):
         return str(self)
 
+class EnumLiteral:
+    def __init__(self, name, pos):
+        self.name = name
+        self.pos = pos
+
+    def __str__(self):
+        return f".{self.name}"
+
+    def __repr__(self):
+        return str(self)
+
 class Ident:
     def __init__(self, name, pos):
         self.name = name

bsc/astgen.py

@@ -239,6 +239,9 @@ def tuple_literal(self, *nodes):
             elems.append(node)
         return TupleLiteral(elems, self.mkpos(nodes[0]) + self.mkpos(nodes[-1]))
 
+    def enum_literal(self, *nodes):
+        return EnumLiteral(nodes[1].name, self.mkpos(nodes[0]) + nodes[1].pos)
+
     def LOGICAL_AND(self, *nodes):
         return BinaryOp.logical_and
 

bsc/grammar.lark

@@ -103,6 +103,7 @@ unary_expr: unary_op* primary_expr
        | AT NAME -> builtin_var
        | expr DOT NAME -> selector_expr
        | path_expr
+       | DOT NAME -> enum_literal
        | LBRACKET [expr (COMMA expr)*] RBRACKET BANG? -> array_literal
        | LBRACE expr COLON expr (COMMA expr COLON expr)* RBRACE -> map_literal
        | LPAREN expr (COMMA expr)* RPAREN -> tuple_literal

examples/syntax.bs

@@ -61,6 +61,9 @@ class Person {
 }
 
 fn main() {
+    var w = WorldLevel.midgard
+    w = .undefined
+
     var x = 666.0e4
     var a = 123
     var q, m, c = (99, true, nil)