Anonymous user
Icon+Unicon/Intro: Difference between revisions
→Lists of Operators: fix re:augments
(→Lists of Operators: fix re:augments) |
|||
Line 229:
: C - co-expression
: v - variable
==== Assignment and Control Operators ====
v op:= expr # augmented assignment (see below)
v :=: v # swap▼
v <- expr # conditional assign▼
v <-> v # reversible swap</lang>▼
|x # repeated alternation▼
==== Unary ====
Line 240 ⟶ 252:
.x # dereference to value
?x # random element/value
▲ |x # repeated alternation
~c # cset complement
^ # regenerate co-expression</lang>
Line 277 ⟶ 288:
s || s # string concatenation
L ||| L # list concatenation
x & x # conjunction</lang>
▲ x | x # alternation</lang>
The operators above may be used in augmented form with normal assignment (i.e., x1 op:= x2; short for x1 := x1 op x2) . Many of these are common and natural, such as any of the mathematical group, concatenation, and comparisons for sorting. And the most common uses will be building results inside loops or scanning operations. Some of the examples include:
<lang Icon>
while x1 +:= x2 # accumulation
Line 299 ⟶ 309:
</lang Icon>
x1 ===:= x2 # obscure x1 := x1, can this be more that a no-op?
s1 ==:= s2 #
n1 =:= n2 # numeric version of above
x1 &:= x2 # x1 := x2 unless x1 or x2 fails</lang>
▲<lang Icon> v := expr # assign
▲ v :=: v # swap
▲ v <- expr # conditional assign
▲ v <-> v # reversible swap
Note that some documentation indicates x1 |:= x2 exists, but it isn't implemented at this time.
▲ x \ i # limit generation to i results </lang>
== Program Flow and Control ==
| |||