Make fn work like lambda and remove lambda
#1228
Conversation
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First thing to come to mind is that lambdas can't be decorated: => (defn double [func] (fn [x] (* (func x) 2)))
=> ((with-decorator double (fn [x] x)) 5)
File "<input>", line 1, column 2
((with-decorator double (fn [x] x)) 5)
^--------------------------------^
HyTypeError: b'Decorated a non-function'But without the changes, example works: (defn double [func] (fn [x] (* (func x) 2)))
=> ((with-decorator double (fn [x] x)) 5)
10
=> ((with-decorator double (lambda [x] x)) 5)
File "<input>", line 1, column 2
((with-decorator double (lambda [x] x)) 5)
^------------------------------------^
HyTypeError: b'Decorated a non-function'In my opinion, this is big enough drawback not to do this change. |
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That could be implemented, but why would you write |
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Point of the code was to show a simple testcase which will fail if this change is pulled in. Actual content of the example decorator isn't important. Currently user can be confident that result of |
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My argument isn't specific to your test case. It applies no matter how complex the decorator or the decorated |
This feature is of dubious value by itself, but it's necessary to allow `defn` to create a lambda instead of a `def`.
That is, allow it to generate a `lambda` instead of a `def` statement if the function body is just an expression. I've removed two uses of with_decorator in hy.compiler because they'd require adding another case to HyASTCompiler.compile_decorate_expression and they have no ultimate effect, anyway. In a few tests, I've added a meaningless statement in `fn` bodies to force generation of a `def`. I've removed `test_fn_compiler_empty_function` rather than rewrite it because it seems like a pain to maintain and not very useful.
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Right, now I follow. Shouldn't test things before second cup of coffee in morning. Indeed, following works as expected: => (defn double [func] (fn [x] (* (func x) 2)))
=> (with-decorator double (defn test [x] x))
=> (test 2)
4 |
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Like the commit message says, "it's necessary to allow |
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So technically, supporting |
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Or, putting it another way, the |
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And that's commit 2,000. This calls for celebration! |
The bug was a regression that I introduced in hylang#1228. I've created a new special form named `fn*` that works like the old `fn` (that is, it always creates a FunctionDef). Since this is intended only for internal use, like `with*`, I haven't documented it.
The bug was a regression that I introduced in hylang#1228. I've created a new special form named `fn*` that works like the old `fn` (that is, it always creates a `FunctionDef`). Since this is intended only for internal use, like `with*`, I haven't documented it.
The bug was a regression that I introduced in #1228. I've created a new special form named `fn*` that works like the old `fn` (that is, it always creates a `FunctionDef`). Since this is intended only for internal use, like `with*`, I haven't documented it.
Closes #910.