Get a scalar, optionally with a default when missing.

Get a scalar, optionally with a default when missing.

Usage

get_scalar(daf, name, default)

Arguments

daf

A DafReader.

name

Scalar name.

default

Value to return when the scalar is absent. If missing and the scalar is absent, an error is raised.

Value

The scalar value.

Examples

# Mirrors readers.jl jldoctests at lines 157 + 165.
get_scalar(example_cells_daf(), "organism") # "human"
#> [1] "human"
get_scalar(example_metacells_daf(), "organism", default = NULL) # NULL
#> NULL