SPI Common Extensions Manual

Glossary
SPI Common Extensions Manual—427508-001
Glossary-15
token map
token map. An SPI structure that describes the fields of an extensible structured token.
Also, a variable name used to refer to an extensible structured token. The token map
includes a token code and a description of the token value: its fields, the null values of
those fields, and the versions of the fields. A token map defines a structure that might
change in some later code version (by the addition of new fields at the end), and the
information in the map lets SPI provide compatibility between different structure
versions. In DDL, a special definition (using the TOKEN-MAP statement) that the DDL
compiler translates into an SPI token map. Token maps have symbolic names of the
form subsys-MAP-name.
token number. The number used by a subsystem to identify each token that it defines. The
token type and the token number together form the token code. Token numbers have
symbolic names of the form subsys-TNM-name.
token type. In SPI, a combination of the token data type and token length; part of the token
code. In DDL, a special definition (using the TOKEN-TYPE statement) that the DDL
compiler translates into an SPI token type. Token types have symbolic names of the
form subsys-TYP-name.
token value. The value assigned to a token.
token-oriented. Programmatic interfaces that convey information in tokens, code-value
pairs accessed by code rather than by address or ordinal position. SPI is a token-
oriented programmatic interface.
upward compatibility. The ability of a requester to operate gracefully with a server of a
higher version. In this case, the requester is upward-compatible with the server, and
the server is downward-compatible with the requester. Compare with downward
compatibility.
version compatibility. The ability of a requester and server of different revision levels to
operate gracefully together.
version number. A 16-bit integer representation of a software version. For Compaq
subsystems, this consists of an uppercase alphabetic character in its left half and a
number in its right half.
warning. A condition, encountered in performing a command or other operation, that can be
significant but does not cause the command or operation to fail. A warning is less
serious than an error. Compare with error.