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digitalmars.D.internals - Parsing string mixin as normal code

reply RazvanN <razvan.nitu1305 gmail.com> writes:
Hi all,

After going through the compiler code that does parsing, I 
noticed that whenever a mixin is encountered, a CompileStatement 
node is created and its contents are parsed later on when 
semantic is performed. I am not sure for other cases, but at 
least for simple string mixins you could parse the string right 
away without instantiating a new parser. Is there a reason for 
deferring the parsing to the semantic analysis phase?

Thank you,
RazvanN
Jul 04
parent Martin Nowak <code dawg.eu> writes:
On Tuesday, 4 July 2017 at 14:48:00 UTC, RazvanN wrote:
 After going through the compiler code that does parsing, I 
 noticed that whenever a mixin is encountered, a 
 CompileStatement node is created and its contents are parsed 
 later on when semantic is performed. I am not sure for other 
 cases, but at least for simple string mixins you could parse 
 the string right away without instantiating a new parser. Is 
 there a reason for deferring the parsing to the semantic 
 analysis phase?
Guess with parsing right away you mean during the initial module parsing. It's the distinguishing between simple and complex that mandates the later parsing. Temporal/order dependencies between different stages are tricky enough in the compiler, better to just stick with one behavior. Also most mixin expressions aren't trivial (at least require concat and usually formatting), so it's hardly optimizing. Might be more interesting for `mixin(import("code.d"));`, but it's fine as is.
Jul 19