16 lines
904 B
Markdown
16 lines
904 B
Markdown
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# How to implement `define-library`?
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* define-library can be nested
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* expressions inside define-library are compiled and evaluated in order sequentially
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* import declarations inside define-library and on the top level are semantically the same
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* each define-library creates one syntactic-env
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* and the body is evaluated as if it's on the top level
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* so each `toplevel definitions`' results are registered to the global table
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* but their renamed symbols are known only to who imported the library.
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## export table
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* import syntax destructively registers renamed symbols taken from export table of the specified library to syntactic env of the library
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* export syntax registers correspoindings of original and renamed symbols to export table of the current library
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* therefore, we need some kind of `forward declaration` support, because export syntax is usually placed at the beginning of source code.
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