Commit e85ee67c authored by Per Bothner's avatar Per Bothner

* kawa.texi: Add notes about using slices to construct sequences.

parent 2b967492
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in 5 minutes and 55 seconds
2020-06-23 Per Bothner <per@bothner.com>
* kawa.texi: Add notes about using slices to construct sequences.
2020-01-15 Per Bothner <per@bothner.com>
* kawa.texi (Options): --browse-manual now defaults to javafx.
......
......@@ -2743,6 +2743,25 @@ Sequences have certain common operations, including indexing and iteration.
interface, but Kawa will also treat strings and native
Java arrays as sequences.)
@subheading Creating sequences
The general syntax for creating a sequence of type @var{seq-type}
with values give by expressions @var{a}, @var{b} ... @var{z} is:
@example
@code{(}@var{seq-type} @var{a} @var{b} ... @var{z}@code{)}
@end example
For example to create a 3-element list of the first 3 natural numbers,
you can write:
@example
(vector 1 (+ 1 1) 3)
@end example
A ``splice operator'' @code{@@}@var{seq} can be used as one the arguments
to append or convert sequences:
@example
(vector 1 @@lst)
@end example
@subheading Lists
In traditional Lisp-family languages, the @dfn{list} is the
......@@ -20286,7 +20305,16 @@ The above expression is equivalent to:
Allocating Java arrays (@pxref{Creating-new-Java-arrays}) uses a
similar pattern:
@example
(int[] 2 3 5 7 11)
(define iarr (int[] 2 3 5 7 11))
@end example
A value argument can use a ``splice operator'' @code{@@@var{expression}}
to ``flatten'' a @ref{Sequences,generalized sequence};
this is a special case of @ref{Application and Arguments Lists,argument list handling}.
This example converts one type of sequence (Java-array of @code{int})
into another (Java-array of @code{float}):
@example
(define farr (float[] @@iarr))
@end example
Sometimes you want to set some named property to an initial value.
......@@ -20743,7 +20771,7 @@ You can specify the initial elements instead of the length:
@end example
This creates a 4-length array, initialized to the given values.
Note this is a variation of the generation object-allocation
Note this is a variation of the general object-allocation
(@pxref{Allocating objects}) pattern. You can explicitly
use the @code{make} function, if you prefer:
@example
......@@ -20762,6 +20790,12 @@ to the default value of zero,
but elements with indexes 0, 1, 50, 51, 80, 81 are initialized
to the values 10, 12, 13, 14, 15, 16, respectively.
You can use the ``splice'' operator (@pxref{Application and Arguments Lists,argument list handling})
to ``flatten'' and convert a @ref{Sequences,generalized sequence}:
@example
(float[] @@some-list)
@end example
@subsection Accessing Java array elements
You can access the elements of a Java array by treating it as
......
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