is_ok

test the validity of values

Synopsis

is_ok(val: any) -> bool

Description

The is_ok function is inspired by the Rust language pattern of the same name and returns true when val is not none or an error. It is a shortcut for ok(val)!=none.

This function is often used to determine the existence of fields in a record, e.g., is_ok(x) is true when this is a record and has the field x, provided its value is not an error or none.

It’s also useful in shaping messy data when applying conditional logic based on the presence of certain fields:

switch
  case a.is_ok() ( ... )
  case b.is_ok() ( ... )
  default ( ... )

Examples

# spq
values {yes:is_ok(foo),no:is_ok(bar)}
# input
{foo:10}
# expected output
{yes:true,no:false}

# spq
values {yes: foo[1].is_ok(),no:foo[4].is_ok()}
# input
{foo:[1,2,3]}
# expected output
{yes:true,no:false}

# spq
values {yes:foo.bar.is_ok(),no:foo.baz.is_ok()}
# input
{foo:{bar:"value"}}
# expected output
{yes:true,no:false}

# spq
values {yes:is_ok(foo+1),no:is_ok(bar+1)}
# input
{foo:10}
# expected output
{yes:true,no:false}

# spq
values bar.is_ok()
# input
1
# expected output
false