6.1 Data Types

In the descriptions below it is assumed that long ints are 32 bits in length. Acutally, SCM is written to work with any long int size larger than 31 bits. With some modification, SCM could work with word sizes as small as 24 bits.

All SCM objects are represented by type SCM. Type SCM come in 2 basic flavors, Immediates and Cells:

• Immediates
• Cells: Non-Immediate types
• Header Cells: Malloc objects
• Subr Cells: Built-in and Compiled Procedures
• Defining Subrs
• Ptob Cells: I/O ports
• Defining Ptobs
• Smob Cells: Miscellaneous datatypes
• Defining Smobs
• Data Type Representations: How they all fit together