`is`

Type predicates for Lua values and filesystem path kinds.

Function names exist in both lowercase and capitalized forms (for example, is.table or is.Table).

is is callable as is(v, tp) where v is the value and tp is any supported type name.

Quick Reference

Type Checks:

Function	Description
`boolean(v)`	Returns `true` when `v` is a boolean.
`Function(v)`	Returns `true` when `v` is a function.
`Nil(v)`	Returns `true` when `v` is `nil`.
`number(v)`	Returns `true` when `v` is a number.
`string(v)`	Returns `true` when `v` is a string.
`table(v)`	Returns `true` when `v` is a table.
`thread(v)`	Returns `true` when `v` is a thread.
`userdata(v)`	Returns `true` when `v` is userdata.

Value Checks:

Function	Description
`False(v)`	Returns `true` when `v` is exactly `false`.
`True(v)`	Returns `true` when `v` is exactly `true`.
`falsy(v)`	Returns `true` when `v` is falsy.
`callable(v)`	Returns `true` when `v` is callable.
`integer(v)`	Returns `true` when `v` is an integer.
`truthy(v)`	Returns `true` when `v` is truthy.

Path Checks:

Function	Description
`block(v)`	Returns `true` when `v` is a block device path.
`char(v)`	Returns `true` when `v` is a char device path.
`device(v)`	Returns `true` when `v` is a block or char device path.
`dir(v)`	Returns `true` when `v` is a directory path.
`fifo(v)`	Returns `true` when `v` is a FIFO path.
`file(v)`	Returns `true` when `v` is a file path.
`link(v)`	Returns `true` when `v` is a symlink path.
`socket(v)`	Returns `true` when `v` is a socket path.

Functions

Type Checks

`boolean(v)`

Returns true when v is a boolean.

lua

is.boolean(true)

`Function(v)`

Returns true when v is a function.

lua

is.Function(function() end)

`Nil(v)`

Returns true when v is nil.

lua

is.Nil(nil)

`number(v)`

Returns true when v is a number.

lua

is.number(3.14)

`string(v)`

Returns true when v is a string.

lua

is.string("hello")

`table(v)`

Returns true when v is a table.

lua

is.table({})

`thread(v)`

Returns true when v is a thread.

lua

is.thread(coroutine.create(function() end))

`userdata(v)`

Returns true when v is userdata.

lua

is.userdata(io.stdout)

Value Checks

`False(v)`

Returns true when v is exactly false.

lua

is.False(false)

`True(v)`

Returns true when v is exactly true.

lua

is.True(true)

`falsy(v)`

Returns true when v is falsy.

lua

is.falsy(false)

`callable(v)`

Returns true when v is callable.

lua

is.callable(function() end)

`integer(v)`

Returns true when v is an integer.

lua

is.integer(42)

`truthy(v)`

Returns true when v is truthy.

lua

is.truthy("non-empty")