interpreter: Add a slice() method to arrays

This can come in handy for instance when a custom target creates both
headers and sources. Slicing the output of a `to_list()` call provides
convenient access to just the headers or just the sources.

1 files changed, 10 insertions, 0 deletions

diff --git a/test cases/common/56 array methods/meson.build b/test cases/common/56 array methods/meson.build
index 3707775ec..3cc1067b9 100644
--- a/test cases/common/56 array methods/meson.build
+++ b/test cases/common/56 array methods/meson.build
@@ -69,6 +69,16 @@ if not combined.contains('ghi')
   error('Combined claims not to contain ghi.')
 endif
 
+# test array slicing
+assert(['a', 'b', 'c'].slice() == ['a', 'b', 'c'])
+assert(['a', 'b', 'c'].slice(step : 2) == ['a', 'c'])
+assert(['a', 'b', 'c'].slice(step : -1) == ['c', 'b', 'a'])
+assert(['a', 'b', 'c'].slice(step : -2) == ['c', 'a'])
+assert(['a', 'b', 'c'].slice(1, 2) == ['b'])
+assert(['a', 'b', 'c'].slice(2, -2) == [])
+assert(['a', 'b', 'c'].slice(-9876543, 2) == ['a', 'b'])
+assert(['a', 'b', 'c', 'd', 'e'].slice(1, 12, step : 2) == ['b', 'd'])
+
 # test array flattening
 x = ['a', ['b'], [[[[[[['c'], 'd']]], 'e']]]]
 assert(x.length() == 3)