diff options
Diffstat (limited to 'src/com/craftinginterpreters/lox/Parser.java')
-rw-r--r-- | src/com/craftinginterpreters/lox/Parser.java | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/src/com/craftinginterpreters/lox/Parser.java b/src/com/craftinginterpreters/lox/Parser.java index 9a9c0e6..9e76a54 100644 --- a/src/com/craftinginterpreters/lox/Parser.java +++ b/src/com/craftinginterpreters/lox/Parser.java @@ -27,7 +27,7 @@ class Parser { } private Expr expression() { - return equality(); + return assignment(); } private Stmt declaration() { @@ -73,6 +73,24 @@ class Parser { return new Stmt.Expression(expr); } + private Expr assignment() { + Expr expr = equality(); + + if (match(EQUAL)) { + Token equals = previous(); + Expr value = assignment(); + + if (expr instanceof Expr.Variable) { + Token name = ((Expr.Variable) expr).name; + return new Expr.Assign(name, value); + } + + error(equals, "Invalid assignment target."); + } + + return expr; + } + private Expr equality() { Expr expr = comparison(); |