Like Corion said, the key to implementing this design is delay :) Perl does it 
$ perl -c -e " foo(1); "
-e syntax OK

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Even though foo() isn't defined yet, perl recognizes it as a function yet to be defined by the syntax(like your tags), so it holds off reporting an error as long as possible (runtime, when it tries to call it) 
$ perl -e " foo(1); "
Undefined subroutine &main::foo called at -e line 1.

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H.O.P is all about this approach, build a tree, walk the tree, modify the tree, compute

The computable things are defined by syntax < >  [ ]  ( ), whether they'll actually compute or be returned verbatim is delayed until runtime

Like perl, TT2 takes the approach that if its not computable, its an error, not a string substitution

Your blind spot seems to be your current implementation -- you keep thinking in terms of substitution s/// instead of function/method calls -- even s/// is not really substitutions, its a series of function/method calls -- each call to s/// is a walk of the tree (flat tree, a string)

In reply to Re^6: hrm, Eval::Compile by Anonymous Monk
in thread hrm, Eval::Compile by Logicus

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