aboutsummaryrefslogtreecommitdiff
path: root/lib/Hash/Merge.rakumod
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Hash/Merge.rakumod')
-rw-r--r--lib/Hash/Merge.rakumod78
1 files changed, 78 insertions, 0 deletions
diff --git a/lib/Hash/Merge.rakumod b/lib/Hash/Merge.rakumod
new file mode 100644
index 0000000..5d496a4
--- /dev/null
+++ b/lib/Hash/Merge.rakumod
@@ -0,0 +1,78 @@
+#! /usr/bin/env false
+
+use v6.d;
+
+unit module Hash::Merge;
+
+#| Merge any number of Hashes together.
+sub merge-hashes (
+ #| Any number of Hashes to merge together.
+ *@hashes,
+
+ --> Hash
+) is export {
+ my %result = @hashes.shift;
+
+ # Nothing to do if we only got 1 argument
+ return %result unless @hashes.elems;
+
+ for ^@hashes.elems {
+ %result = merge-hash(%result, @hashes.shift);
+ }
+
+ %result;
+}
+
+#| Merge two hashes together.
+sub merge-hash (
+ #| The original Hash to merge the second Hash into.
+ %first,
+
+ #| The second hash, which will be merged into the first Hash.
+ %second,
+
+ #| Boolean to set whether Associative objects should be merged on their
+ #| own. When set to False, Associative objects in %second will
+ #| overwrite those from %first.
+ Bool:D :$deep = True,
+
+ #| Boolean to set whether Positional objects should be appended. When
+ #| set to False, Positional objects in %second will overwrite those
+ #| from %first.
+ Bool:D :$positional-append = True,
+
+ --> Hash
+) is export {
+ my %result = %first;
+
+ for %second.keys -> $key {
+ # If the key doesn't exist yet in %first, it can be inserted without worry.
+ if (%first{$key}:!exists) {
+ %result{$key} = %second{$key};
+ next;
+ }
+
+ given (%first{$key}) {
+ # Associative objects need to be merged deeply.
+ when Associative {
+ %result{$key} = $deep
+ ?? merge-hash(%first{$key}, %second{$key}, :$deep, :$positional-append)
+ !! %second{$key}
+ }
+ # Positional objects can be merged or overwritten depending on $append-array.
+ when Positional {
+ %result{$key} = $positional-append
+ ?? (|%first{$key}, |%second{$key})
+ !! %second{$key}
+ }
+ # Anything else will just overwrite.
+ default {
+ %result{$key} = %second{$key};
+ }
+ }
+ }
+
+ %result;
+}
+
+# vim: ft=raku ts=4 sw=4 et