GH-37835: [MATLAB] Improve arrow.tabular.Schema display

[sgilmore10]

Rationale for this change

We would like to change how arrow.tabular.Schemas are displayed in the Command Window. Below is the current display:

>> field1 =  arrow.field("A", arrow.time32());
>> field2 = arrow.field("B", arrow.boolean());
>>s = arrow.schema([field1 field2])

s = 

A: time32[s]
B: bool

This display is not very MATLAB-like.

What changes are included in this PR?

1. Updated the display of arrow.tabular.Schema. Below is the new display:

>> field1 =  arrow.field("A", arrow.time32());
>> field2 = arrow.field("B", arrow.boolean());
>> s = arrow.schema([field1 field2])

s = 

  Arrow Schema with 2 fields:

    A: Time32 | B: Boolean

When MATLAB is opened in desktop mode, Schema, Time32, and Boolean are hyperlinks users can click on to view the help text for the different class types.

Are these changes tested?

Yes. Added three new test cases to tSchema.m:

1. TestDisplaySchemaZeroFields
2. TestDisplaySchemaOneField
3. TestDisplaySchemaMultipleFields

Are there any user-facing changes?

Yes. arrow.tabular.Schemas will be displayed differently in the Command Window.

Notes

Once #37826 is merged, I will rebase my changes and mark this PR as ready for review.

• Closes: [MATLAB] Improve arrow.tabular.Schema display #37835

[kevingurney]

I haven't looked at the code yet in detail, but just a thought - what if we made the display look similar to the following?

   Arrow tabular Schema with 3 fields:

   ┌─────────────────┬─────────────────┬──────────────┐
   │ Name: A         │ Name: B         │ Name: C      │
   │ Type: Time32    │ Type: Boolean   │ Type: String │
   └─────────────────┴─────────────────┴──────────────┘

This is just a suggestion. Let me know what you think.

[sgilmore10]

I haven't looked at the code yet in detail, but just a thought - what if we made the display look similar to the following?

   Arrow tabular Schema with 3 fields:

   ┌─────────────────┬─────────────────┬──────────────┐
   │ Name: A         │ Name: B         │ Name: C      │
   │ Type: Time32    │ Type: Boolean   │ Type: String │
   └─────────────────┴─────────────────┴──────────────┘

This is just a suggestion. Let me know what you think.

I like this. It makes it clear this object is an Arrow Schema and not a MATLAB table. I can see how the original design may confuse users in that sense.

[kevingurney]

I discussed this more with @sgilmore10, and we realized that the Unicode box-drawing characters don't align properly when certain Unicode characters are used. So, for now, we think it is best to go with a simpler display.

[sgilmore10]

I discussed this more with @sgilmore10, and we realized that the Unicode box-drawing characters don't align properly when certain Unicode characters are used. So, for now, we think it is best to go with a simpler display.

Based on our discussion, I've updated the Schema display to the following:

>> field1 =  arrow.field("A", arrow.time32());
>> field2 = arrow.field("B", arrow.boolean());
>> s = arrow.schema([field1 field2])

s = 

  Arrow Schema with 2 fields:

    A: Time32 | B: Boolean

When in desktop mode, Schema, Time32, and Boolean are hyperlinks to the help text for each class type.

[kevingurney]

Thank you for working on this, @sgilmore10! This is a great improvement to the display! Thank you for iterating on the design with me!

[kevingurney]

+1

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 5 benchmarking runs that have been run so far on merge-commit 00efb06.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about possible false positives for unstable benchmarks that are known to sometimes produce them.