symbolic_expression(lambda x, y: ...)

[mkoeppe]

We extend the global binding symbolic_expression to accept a callable such as those created by lambda expressions.

The result is a callable symbolic expression, in which the formal arguments of the callable are the symbolic arguments.

Example:

symbolic_expression(lambda x,y: x^2+y^2) == (SR.var("x")^2 + SR.var("y")^2).function(SR.var("x"), SR.var("y"))

This will provide convenient syntax in particular in connection to ConditionSet (#32089).

Instead of

sage: predicate(x, y, z) = sqrt(x^2 + y^2 + z^2) < 12  # preparser syntax, creates globals
sage: ConditionSet(ZZ^3, predicate)

one would then be able to write

sage: ConditionSet(ZZ^3, symbolic_expression(lambda x, y, z: 
....:     sqrt(x^2 + y^2 + z^2) < 12))

CC: @egourgoulhon @tscrim @nbruin @kcrisman

Component: symbolics

Author: Matthias Koeppe

Branch/Commit: 2b5535f

Reviewer: Travis Scrimshaw, Karl-Dieter Crisman

Issue created by migration from https://trac.sagemath.org/ticket/32103

[mkoeppe]

Branch: u/mkoeppe/symbolic_expression_lambda_x__y______

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Changed branch from u/mkoeppe/symbolic_expression_lambda_x__y______ to none

[slel]

comment:7

Guessing the branch field got emptied by mistake.

---

New commits:

e523ac0

sage.calculus.all.symbolic_expression: Handle callables

[slel]

Commit: e523ac0

[slel]

Branch: u/mkoeppe/symbolic_expression_lambda_x__y______

[mkoeppe]

comment:8

Thanks for catching this!

[tscrim]

comment:10

Green bot => positive review.

[tscrim]

Reviewer: Travis Scrimshaw

[sagetrac-git]

Changed commit from e523ac0 to d2e8c8f

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

d2e8c8f

symbolic_expression: Update doctest output

[kcrisman]

comment:12

On a second pass, I think this code (and the related at #32103) looks good. An additional (TEST only) of this using several types of non-lambda functions could be useful. Patchbot seems to be not giving info at the current time.

[sagetrac-git]

Changed commit from d2e8c8f to 2b5535f

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

2b5535f

sage.calculus.all.symbolic_expression: Add more tests

[mkoeppe]

comment:14

Good idea, done.

[kcrisman]

comment:15

Great. And good call on the second set of tests confirming only (Parameter.POSITIONAL_ONLY, Parameter.POSITIONAL_OR_KEYWORD) works. Once patchbot says yes I say this is fine, unless Travis has something additional to say about the new tests.

[kcrisman]

Changed reviewer from Travis Scrimshaw to Travis Scrimshaw, Karl-Dieter Crisman

[tscrim]

comment:16

Nope, I have no additional comments.

[mkoeppe]

comment:17

Then let's get this in please

[kcrisman]

comment:18

Patchbot green is all I wanted, and sounds like Travis is okay with it.

[mkoeppe]

comment:19

Thanks!

[vbraun]

Changed branch from u/mkoeppe/symbolic_expression_lambda_x__y______ to 2b5535f