HELP TWIDDLYBRA Steven Hardy Mar 1982
Updated: Adrian Howard Mar 1992
Twiddly brackets, "{" and "}", tell the POP-11 system to build a vector
of the enclosed items. For example, below is a vector of words and
numbers:
{2 cats 3 dogs 5 birds}
Vectors can be nested. Percent symbols (%) and up-arrows (^ and ^^) can
be used within a vector expression to cause part of the expression to be
evaluated rather than quoted, e.g.
vars n1=3, n2=5, n3=7;
{ ^n1 cats ^n2 dogs ^n3 birds }=>
** {3 cats 5 dogs 7 birds}
Twiddly brackets may be preceded by -cons_with- to create other
structures than vectors (see HELP *CONS_WITH.)
See TEACH *BRACKETS for a tutorial introduction to the use of brackets
in POP-11, and TEACH *ARROW for the use of up-arrows.
Also see:
* PERCENT --- Uses of the % symbol in POP-11
* INITV --- Construction of vectors
* CONSVECTOR* SUBSCRV --- Accessing and updating vector elements
* SQUAREBRA --- Constructing lists using square brackets
* ROUNDBRA --- The use of round brackets in POP-11
* #_< --- Compilation brackets
* #| --- Stack counting brackets
--- C.all/help/twiddlybra
--- Copyright University of Sussex 1992. All rights reserved. ----------