patch 8.2.0878: no reduce() function
Problem: No reduce() function.
Solution: Add a reduce() function. (closes #5481)
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 1954730..7b85acd 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2679,6 +2679,8 @@
readdirex({dir} [, {expr}]) List file info in {dir} selected by {expr}
readfile({fname} [, {type} [, {max}]])
List get list of lines from file {fname}
+reduce({object}, {func} [, {initial}])
+ any reduce {object} using {func}
reg_executing() String get the executing register name
reg_recording() String get the recording register name
reltime([{start} [, {end}]]) List get time value
@@ -7965,6 +7967,26 @@
Can also be used as a |method|: >
GetFileName()->readfile()
+reduce({object}, {func} [, {initial}]) *reduce()* *E998*
+ {func} is called for every item in {object}, which can be a
+ |List| or a |Blob|. {func} is called with two arguments: the
+ result so far and current item. After processing all items
+ the result is returned.
+
+ {initial} is the initial result. When omitted, the first item
+ in {object} is used and {func} is first called for the second
+ item. If {initial} is not given and {object} is empty no
+ result can be computed, an E998 error is given.
+
+ Examples: >
+ echo reduce([1, 3, 5], { acc, val -> acc + val })
+ echo reduce(['x', 'y'], { acc, val -> acc .. val }, 'a')
+ echo reduce(0z1122, { acc, val -> 2 * acc + val })
+<
+ Can also be used as a |method|: >
+ echo mylist->reduce({ acc, val -> acc + val }, 0)
+
+
reg_executing() *reg_executing()*
Returns the single letter name of the register being executed.
Returns an empty string when no register is being executed.