Repeated Patterns
| expr.. | a pattern or other expression repeated one or more times |
| expr... | a pattern or other expression repeated zero or more times |
Repeated patterns.
Multiple blanks such as
allow you to give patterns in which sequences of arbitrary expressions can occur. The
Mathematica pattern repetition operators
and
allow you to construct patterns in which particular forms can be repeated any number of times. Thus, for example,
represents any expression of the form
,
,
, and so on.
The pattern
allows the argument
to be repeated any number of times.
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This pattern allows any number of
arguments, followed by any number of
arguments.
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Here each argument can be either
or
.
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You can use
and
to represent repetitions of any pattern. If the pattern contains named parts, then each instance of these parts must be identical.
This defines a function whose argument must consist of a list of pairs.
The definition applies in this case.
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With this definition, the second elements of all the pairs must be the same.
The definition applies in this case.
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The pattern
x.. can be extended to two arguments to control the number of repetitions more precisely.
| p.. or Repeated[p] | a pattern or other expression repeated one or more times |
| Repeated[p,max] | a pattern repeated up to max times |
| Repeated[p,{min,max}] | a pattern repeated between min and max times |
| Repeated[p,{n}] | a pattern repeated exactly n times |
Controlling the number of repetitions.
This finds from two to three repetitions of the argument
a.
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