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8da27a1a09
# Description
This PR creates a new `Record` type to reduce duplicate code and
possibly bugs as well. (This is an edited version of #9648.)
- `Record` implements `FromIterator` and `IntoIterator` and so can be
iterated over or collected into. For example, this helps with
conversions to and from (hash)maps. (Also, no more
`cols.iter().zip(vals)`!)
- `Record` has a `push(col, val)` function to help insure that the
number of columns is equal to the number of values. I caught a few
potential bugs thanks to this (e.g. in the `ls` command).
- Finally, this PR also adds a `record!` macro that helps simplify
record creation. It is used like so:
```rust
record! {
"key1" => some_value,
"key2" => Value::string("text", span),
"key3" => Value::int(optional_int.unwrap_or(0), span),
"key4" => Value::bool(config.setting, span),
}
```
Since macros hinder formatting, etc., the right hand side values should
be relatively short and sweet like the examples above.
Where possible, prefer `record!` or `.collect()` on an iterator instead
of multiple `Record::push`s, since the first two automatically set the
record capacity and do less work overall.
# User-Facing Changes
Besides the changes in `nu-protocol` the only other breaking changes are
to `nu-table::{ExpandedTable::build_map, JustTable::kv_table}`.
33 lines
783 B
Rust
33 lines
783 B
Rust
use nu_protocol::Value;
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use std::collections::HashSet;
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pub fn get_columns(input: &[Value]) -> Vec<String> {
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let mut columns = vec![];
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for item in input {
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let Value::Record { val, .. } = item else {
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return vec![];
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};
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for col in &val.cols {
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if !columns.contains(col) {
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columns.push(col.to_string());
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}
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}
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}
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columns
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}
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// If a column doesn't exist in the input, return it.
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pub fn nonexistent_column(inputs: Vec<String>, columns: Vec<String>) -> Option<String> {
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let set: HashSet<String> = HashSet::from_iter(columns.iter().cloned());
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for input in &inputs {
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if set.contains(input) {
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continue;
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}
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return Some(input.clone());
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}
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None
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}
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