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Diffstat (limited to 'doc/concepts/expressions.md')
| -rw-r--r-- | doc/concepts/expressions.md | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/doc/concepts/expressions.md b/doc/concepts/expressions.md index 79b114f3..74058f84 100644 --- a/doc/concepts/expressions.md +++ b/doc/concepts/expressions.md @@ -219,6 +219,30 @@ variables specified at `"var_key"` and `"var_val"` (literal strings, default values `"_"` and `"$_"`, respectively). The result of the evaluation is the list of those values. +##### Zipping + +###### `"zip_with"` + +The keys `"range_1"` and `"range_2"` are evaluated and have +to evaluate to lists. For each pair of entries, one from each +list, in order, the expression `"body"` is evaluated in an +environment obtained from the original one by correspondingly +setting the variables specified at `"var_1"` and `"var_2"` +(default values `"$1"` and `"$2"`, respectively). The result of +the evaluation is the list of those values. If the input lists +are of different lengths, any entry with no correspondence in +the other list is ignored. + +###### `"zip_map"` + +The keys `"range_key"` and `"range_val"` are evaluated and have +to evaluate to lists. The result is a map, from an entry in +`"range_key"` to the entry in `"range_val"` with the same index. +If the input lists are of different lengths, any entry with no +correspondence in the other list is ignored. It is equivalent but +more convenient and more performant to a `"zip_with"` expression +generating a list of maps combined with a `map_union`. + ##### Folding: `"foldl"` The key `"range"` is evaluated and has to evaluate to a list. |