Do we need/want any other summary functions/methods on ts?

[gregorgorjanc]

Related to #12 and

tskitr/R/inst/STATE_and_AIMS.md

Line 309 in 88985e1

### 4) Call `tskit` C API in R code in an R session or another R package (TODO)

[gregorgorjanc]

Some candidates based on searching tsk_treeseq_get_ in trees.c. Maybe best to mimick the Python summary/str/repr method!?

ts$metadata
tsk_treeseq_get_metadata
Get the top-level tree sequence metadata.
Returns a pointer to the metadata string, which is owned by the tree sequence and
not null-terminated.

tsk_treeseq_get_metadata_length
Get the length of top-level tree sequence metadata

ts2$metadata_schema
tsk_treeseq_get_metadata_schema
Get the top-level tree sequence metadata schema.
Returns a pointer to the metadata schema.

tsk_treeseq_get_metadata_schema_length
Get the length of the top-level tree sequence metadata schema.
Returns the length of the metadata schema string.

ts$discrete_time
tsk_treeseq_get_discrete_time
Get the discrete time status
Returns true if all times are discrete.

ts$time_units
tsk_treeseq_get_time_units
Get the time units string
Returns a pointer to the time units.

tsk_treeseq_get_time_units_length
Get the length of time units string
Returns the length of the time units.

ts$max_time
tsk_treeseq_get_max_time
Get the max time in node table and mutation table
Returns the max time of all nodes and mutations.

ts$min_time
tsk_treeseq_get_min_time
Get the min time in node table and mutation table
Returns the min time of all nodes and mutations.

tsk_treeseq_get_discrete_genome
If all the genomic locations in the tree sequence are discrete integer values
then this flag will be true.
Returns true if all genomic locations are discrete.

[gregorgorjanc]

Python print method produces the following text (there is also HTML version):

>>> print(ts)
╔═══════════════════════════╗
║TreeSequence               ║
╠═══════════════╤═══════════╣
║Trees          │         26║
╟───────────────┼───────────╢
║Sequence Length│     10,000║
╟───────────────┼───────────╢
║Time Units     │generations║
╟───────────────┼───────────╢
║Sample Nodes   │        160║
╟───────────────┼───────────╢
║Total Size     │  185.4 KiB║
╚═══════════════╧═══════════╝
╔═══════════╤═════╤═════════╤════════════╗
║Table      │Rows │Size     │Has Metadata║
╠═══════════╪═════╪═════════╪════════════╣
║Edges      │  414│ 12.9 KiB│          No║
╟───────────┼─────┼─────────┼────────────╢
║Individuals│   80│  2.2 KiB│          No║
╟───────────┼─────┼─────────┼────────────╢
║Migrations │    0│  8 Bytes│          No║
╟───────────┼─────┼─────────┼────────────╢
║Mutations  │2,700│ 97.6 KiB│          No║
╟───────────┼─────┼─────────┼────────────╢
║Nodes      │  344│  9.4 KiB│          No║
╟───────────┼─────┼─────────┼────────────╢
║Populations│    1│224 Bytes│         Yes║
╟───────────┼─────┼─────────┼────────────╢
║Provenances│    2│  1.8 KiB│          No║
╟───────────┼─────┼─────────┼────────────╢
║Sites      │2,376│ 58.0 KiB│          No║
╚═══════════╧═════╧═════════╧════════════╝

The implementation of this print method is at https://github.com/tskit-dev/tskit/blob/03ad862aa5830134d840ba150b4005ad7a5a7def/python/tskit/trees.py#L4468. Two quirks. One, the byte counting is done on Python side (which we won't replicate here). Two, metadata is stored at C level, but not decodable (see https://github.com/tskit-dev/tskit/blob/03ad862aa5830134d840ba150b4005ad7a5a7def/docs/c-api.rst?plain=1#L42)