Fast reference to common SRFI

Scheme Requests for Implementation (SRFI) provide Scheme users portable, useful code not necessarily present in typically minimalist language implementations. SRFI are well documented on the dedicated website, but it is not always clear what is the best or most idiomatic solution for a given application. The list below is strongly based on ongoing discussions for the Revised 7 Report on the Algorithmic Language Scheme (R7RS).

(Of course not all of the following SRFI may be distributed or packaged for a given implementation. Note that SRFI documentation often refers to similar SRFI that may be instead available for the given implementation. For instance, currently SRFI 125 for hash tables is not available as a CHICKEN Scheme package, but the older SRFI 69 is.)

Basic libraries

• Lists: SRFI 1.
• Vectors: SRFI 133.
• Strings: SRFI 13 (see also SRFI 130).
• Sorting: SRFI 132.

Immutability

• Immutable pairs/lists: SRFI 116.
• Random access pairs/lists: SRFI 101.
• Immutable deques: SRFI 134.
• Immutable text: SRFI 135.

Laziness

• Generators: SRFI 121.
• Lazy sequences: SRFI 127.
• Streams: SRFI 41.

Miscellaneous

• Boxes (single-slot records): SRFI 111.
• Comparators: SRFI 128.
• Comprehensions: SRFI 42.
• Ephemerons: SRFI 124.
• List queues: SRFI 117.
• Regular expressions: SRFI 115.
• Titlecase: SRFI 129.

Numeric

• 'Numbers` SRFIs.

Sets and maps

• Sets and bags: SRFI 113 (see also SRFI 1 if performance is not critical).
• Character sets: SRFI 14.
• Hash tables: SRFI 125.