html_url,issue_url,id,node_id,user,user_label,created_at,updated_at,author_association,body,reactions,issue,issue_label,performed_via_github_app
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239772256,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239772256,IC_kwDOCGYnMM5J5Wxg,9599,simonw,2022-09-07T19:07:51Z,2022-09-07T19:09:52Z,OWNER,"Or... I could automatically register multiple copies of the function of different arities!

If I'm going to do something like that though I need to think carefully about how functions that have keyword-only arguments should work: https://peps.python.org/pep-3102/

```python
def compare(a, b, *ignore, key=None):
    ...
```
I should think about how these work with `db.register_function()` anyway, since SQL functions cannot support keyword arguments.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239766987,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239766987,IC_kwDOCGYnMM5J5VfL,9599,simonw,2022-09-07T19:01:49Z,2022-09-07T19:01:49Z,OWNER,"OK with this:
```diff
diff --git a/sqlite_utils/cli.py b/sqlite_utils/cli.py
index c51b101..93d82a9 100644
--- a/sqlite_utils/cli.py
+++ b/sqlite_utils/cli.py
@@ -30,6 +30,7 @@ from .utils import (
     Format,
     TypeTracker,
 )
+from . import recipes
 
 
 CONTEXT_SETTINGS = dict(help_option_names=[""-h"", ""--help""])
@@ -3029,7 +3030,7 @@ def _load_extensions(db, load_extension):
 def _register_functions(db, functions):
     # Register any Python functions as SQL functions:
     sqlite3.enable_callback_tracebacks(True)
-    globals = {}
+    globals = {""r"": recipes, ""recipes"": recipes}
     try:
         exec(functions, globals)
     except SyntaxError as ex:
@@ -3037,4 +3038,4 @@ def _register_functions(db, functions):
     # Register all callables in the locals dict:
     for name, value in globals.items():
         if callable(value) and not name.startswith(""_""):
-            db.register_function(value, name=name)
+            db.register_function(value, name=name, ignore_defaults=True)
diff --git a/sqlite_utils/db.py b/sqlite_utils/db.py
index 27c46b0..1407d23 100644
--- a/sqlite_utils/db.py
+++ b/sqlite_utils/db.py
@@ -370,6 +370,7 @@ class Database:
         self,
         fn: Callable = None,
         deterministic: bool = False,
+        ignore_defaults: bool = False,
         replace: bool = False,
         name: Optional[str] = None,
     ):
@@ -397,7 +398,10 @@ class Database:
 
         def register(fn):
             fn_name = name or fn.__name__
-            arity = len(inspect.signature(fn).parameters)
+            params = inspect.signature(fn).parameters
+            if ignore_defaults:
+                params = [p for p in params if params[p].default is inspect._empty]
+            arity = len(params)
             if not replace and (fn_name, arity) in self._registered_functions:
                 return fn
             kwargs = {}
```
I can now do this:
```
% sqlite-utils memory --functions 'parsedate = r.parsedate' 'select parsedate(""1st jan"")'
[{""parsedate(\""1st jan\"")"": ""2022-01-01""}]
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239763997,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239763997,IC_kwDOCGYnMM5J5Uwd,9599,simonw,2022-09-07T18:57:59Z,2022-09-07T18:58:10Z,OWNER,"Here's how to detect defaults in the function signature:
```pycon
>>> import inspect
>>> def foo(a, b, c=1, d=2):
...      pass
... 
>>> inspect.signature(foo)
<Signature (a, b, c=1, d=2)>
>>> inspect.signature(foo).parameters
mappingproxy(OrderedDict([('a', <Parameter ""a"">), ('b', <Parameter ""b"">), ('c', <Parameter ""c=1"">), ('d', <Parameter ""d=2"">)]))
>>> inspect.signature(foo).parameters['c']
<Parameter ""c=1"">
>>> dir(inspect.signature(foo).parameters['c'])
['KEYWORD_ONLY', 'POSITIONAL_ONLY', 'POSITIONAL_OR_KEYWORD', 'VAR_KEYWORD', 'VAR_POSITIONAL', '__class__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__', '__slots__', '__str__', '__subclasshook__', '_annotation', '_default', '_kind', '_name', 'annotation', 'default', 'empty', 'kind', 'name', 'replace']
>>> inspect.signature(foo).parameters['c'].default
1
>>> inspect.signature(foo).parameters['a'].default
<class 'inspect._empty'>
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239762561,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239762561,IC_kwDOCGYnMM5J5UaB,9599,simonw,2022-09-07T18:56:13Z,2022-09-07T18:56:13Z,OWNER,"I could do this:
```python
 # Register all callables in the locals dict: 
 for name, value in globals.items(): 
     if callable(value) and not name.startswith(""_""): 
         db.register_function(value, name=name, ignore_params_with_defaults=True) 
```
Introducing a new `ignore_params_with_defaults` option.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239762031,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239762031,IC_kwDOCGYnMM5J5URv,9599,simonw,2022-09-07T18:55:30Z,2022-09-07T18:55:30Z,OWNER,That would be a breaking change though - existing code that registers functions with default parameters should continue to work unchanged (unless I want to ship `sqlite-utils` 4.0).,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239761280,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239761280,IC_kwDOCGYnMM5J5UGA,9599,simonw,2022-09-07T18:54:51Z,2022-09-07T18:54:51Z,OWNER,"I could teach this code here to only register the function using arguments that don't have default parameters:

https://github.com/simonw/sqlite-utils/blob/d9b9e075f07a20f1137cd2e34ed5d3f1a3db4ad8/sqlite_utils/cli.py#L3037-L3040

Or even this code here:

https://github.com/simonw/sqlite-utils/blob/d9b9e075f07a20f1137cd2e34ed5d3f1a3db4ad8/sqlite_utils/db.py#L398-L418
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239760001,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239760001,IC_kwDOCGYnMM5J5TyB,9599,simonw,2022-09-07T18:53:17Z,2022-09-07T18:53:17Z,OWNER,"So you would need to do this instead:
```
sqlite-utils memory 'select parsedate(""1st jan"")' --functions '
def parsedate(s):
    return r.parsedate(s)
'
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239759022,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239759022,IC_kwDOCGYnMM5J5Tiu,9599,simonw,2022-09-07T18:52:08Z,2022-09-07T18:52:08Z,OWNER,"It's not quite that simple. I tried applying this patch:

```diff
diff --git a/sqlite_utils/cli.py b/sqlite_utils/cli.py
index c51b101..33e4d90 100644
--- a/sqlite_utils/cli.py
+++ b/sqlite_utils/cli.py
@@ -30,6 +30,7 @@ from .utils import (
     Format,
     TypeTracker,
 )
+from . import recipes
 
 
 CONTEXT_SETTINGS = dict(help_option_names=[""-h"", ""--help""])
@@ -3029,7 +3030,7 @@ def _load_extensions(db, load_extension):
 def _register_functions(db, functions):
     # Register any Python functions as SQL functions:
     sqlite3.enable_callback_tracebacks(True)
-    globals = {}
+    globals = {""r"": recipes, ""recipes"": recipes}
     try:
         exec(functions, globals)
     except SyntaxError as ex:
```

Then got this:

```
% sqlite-utils memory --functions 'parsedate = r.parsedate' 'select parsedate(""1st jan"")'
Error: wrong number of arguments to function parsedate()
% sqlite-utils memory --functions 'parsedate = r.parsedate' 'select parsedate(""1st jan"", 0, 0, 0)' 
[{""parsedate(\""1st jan\"", 0, 0, 0)"": ""2022-01-01""}]
```
The problem here is that the `parsedate` function signature looks like this:

https://github.com/simonw/sqlite-utils/blob/d9b9e075f07a20f1137cd2e34ed5d3f1a3db4ad8/sqlite_utils/recipes.py#L8

But the code that register SQL functions introspects that signature, so creates a SQL function that requires four arguments.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239699276,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239699276,IC_kwDOCGYnMM5J5E9M,9599,simonw,2022-09-07T17:49:49Z,2022-09-07T17:49:49Z,OWNER,"This feature is a tiny bit weird though: the recipe functions are not exposed to SQL by default, they are instead designed to be used with `sqlite-utils convert`. I guess with `--functions` support you could do something like this:

    sqlite-utils data.db ""update mytable set col1 = parsedate(col1)"" --functions ""parsedate = r.parsedate""","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1239697643,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1239697643,IC_kwDOCGYnMM5J5Ejr,9599,simonw,2022-09-07T17:48:00Z,2022-09-07T17:48:00Z,OWNER,Will also need to update documentation here: https://sqlite-utils.datasette.io/en/stable/cli.html#defining-custom-sql-functions,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,
https://github.com/simonw/sqlite-utils/issues/484#issuecomment-1238607591,https://api.github.com/repos/simonw/sqlite-utils/issues/484,1238607591,IC_kwDOCGYnMM5J06bn,9599,simonw,2022-09-06T20:16:39Z,2022-09-06T20:16:39Z,OWNER,"Here's the implementation for recipes at the moment: https://github.com/simonw/sqlite-utils/blob/5b969273f1244b1bcf3e4dc071cdf17dab35d5f8/sqlite_utils/utils.py#L434-L441

And here's the `--functions` implementation that doesn't expose them: https://github.com/simonw/sqlite-utils/blob/5b969273f1244b1bcf3e4dc071cdf17dab35d5f8/sqlite_utils/cli.py#L3029-L3040","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1363766973,Expose convert recipes to `sqlite-utils --functions`,