6.9 mischief/maybe: Optional Values

package: mischief

struct
(struct yes (value)
#:transparent)
value : any/c

A struct that can be used for optional values that can include #false.

procedure
(no? x) → boolean?
x : any/c

Equivalent to (false? x).

procedure
(no) → #false

Returns #false.

procedure
(maybe? x) → boolean?
x : any/c

Equivalent to (or (yes? x) (no? x)).

1	Structured Debugging
2	Printing and Error Messages
3	Macros and Syntax Transformers
4	Modules
5	Definitions and Binding Forms
6	First-Order Datatypes
7	Functions and Flow Control
8	Typesetting Formats

6.1	mischief/ list: Lists and Pairs
6.2	mischief/ string: Strings
6.3	mischief/ symbol: Symbols
6.4	mischief/ keyword: Keywords
6.5	mischief/ boolean: Booleans and Conditionals
6.6	mischief/ struct: User-Defined Datatypes
6.7	mischief/ dict: Dictionaries
6.8	mischief/ stream: Streams
6.9	mischief/ maybe: Optional Values
6.10	mischief/ quotation: Quoting Values as S-expressions
6.11	mischief/ sort: Topological Sorting