hbobenicio / lox Goto Github PK

It doesn't make sense to care about scanner if you just need to use a parser. API would improve if scanner were inside the parser.

• Move files to the ast dir. Refactor include directives
• Prefix symbols with clox_ast_
• Separate expr visitor free into its own module
• Separate expr visitor eval into its own module

Whenever a new string value is evaluated by the interpreter, a new string is allocated. So, when setting a new value, the now useless old string must be deallocated.

In the end, after the eval method finish, the caller or the callee (interpreter) must deallocate the resulting string too.

#BlackLivesMatter

• Refactor the clox_ast_expr_visitor and all its implementations to return an int
• Expose and Chain expr evaluation errors in the expr_eval_visitor implementation for the interpreter
• Implement the synchronize function to handle error recovery in the declarations parsing level (see chapter 8)

Make the lifecycle of these data independent somehow:

• Input source file (program) contents
• Scanner (and its tokens dynamic array)
• Parser
• AST
• Interpreter

It's better to allocate than to depend on old data structures which are not necessarily anymore.

Look at 8.2.2

Chapter 7 - Evaluating Expressions - Challenge 2.

"Many languages define + such that if either operand is a string, the other is converted to a string and the results are then concatenated. For example, "scone" + 4 would yield scone4. Extend the code in visitBinaryExpr() to support that."