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Git stores snapshots, not diffs, and therefore could just as well be considered storing ASTs. The trick is writing a useful diff/merge for them. Programmers also don’t think in ASTs, arguably even less so than lines. The problem is not as formal as it looks.

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There’s great irony in someone who’s name is “morelisp” saying that programmers don’t think in ASTs. Lisp syntax is the AST.

Which also means the Lisp AST is not great to diff with.

First, it's too weak - you need to at least recognize special top-level defun-style forms, or you'll generate some minimal diff between two totally different functions just because they both use the same cond pattern or whatever.

Second, reader macros mean you can't really work on the source AST in the first place, unless you also teach the diff tool all your reader macros.

> Programmers also don’t think in ASTs,

Citation needed

T_PAAMAYIM_NEKUDOTAYIM

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