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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}`.
96 lines
3.1 KiB
Rust
96 lines
3.1 KiB
Rust
use nu_plugin::{EvaluatedCall, LabeledError};
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use nu_protocol::{Record, Value};
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pub struct Example;
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impl Example {
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fn print_values(
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&self,
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index: u32,
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call: &EvaluatedCall,
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input: &Value,
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) -> Result<(), LabeledError> {
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// Note. When debugging your plugin, you may want to print something to the console
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// Use the eprintln macro to print your messages. Trying to print to stdout will
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// cause a decoding error for your message
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eprintln!("Calling test {index} signature");
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eprintln!("value received {input:?}");
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// To extract the arguments from the Call object you can use the functions req, has_flag,
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// opt, rest, and get_flag
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//
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// Note that plugin calls only accept simple arguments, this means that you can
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// pass to the plug in Int and String. This should be improved when the plugin has
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// the ability to call back to NuShell to extract more information
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// Keep this in mind when designing your plugin signatures
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let a: i64 = call.req(0)?;
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let b: String = call.req(1)?;
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let flag = call.has_flag("flag");
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let opt: Option<i64> = call.opt(2)?;
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let named: Option<String> = call.get_flag("named")?;
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let rest: Vec<String> = call.rest(3)?;
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eprintln!("Required values");
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eprintln!("a: {a:}");
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eprintln!("b: {b:}");
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eprintln!("flag: {flag:}");
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eprintln!("rest: {rest:?}");
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if let Some(v) = opt {
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eprintln!("Found optional value opt: {v:}")
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} else {
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eprintln!("No optional value found")
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}
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if let Some(v) = named {
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eprintln!("Named value: {v:?}")
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} else {
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eprintln!("No named value found")
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}
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Ok(())
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}
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pub fn test1(&self, call: &EvaluatedCall, input: &Value) -> Result<Value, LabeledError> {
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self.print_values(1, call, input)?;
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Ok(Value::Nothing { span: call.head })
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}
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pub fn test2(&self, call: &EvaluatedCall, input: &Value) -> Result<Value, LabeledError> {
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self.print_values(2, call, input)?;
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let cols = vec!["one".to_string(), "two".to_string(), "three".to_string()];
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let vals = (0..10i64)
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.map(|i| {
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let vals = (0..3)
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.map(|v| Value::int(v * i, call.head))
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.collect::<Vec<Value>>();
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Value::record(
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Record {
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cols: cols.clone(),
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vals,
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},
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call.head,
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)
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})
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.collect::<Vec<Value>>();
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Ok(Value::List {
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vals,
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span: call.head,
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})
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}
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pub fn test3(&self, call: &EvaluatedCall, input: &Value) -> Result<Value, LabeledError> {
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self.print_values(3, call, input)?;
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Err(LabeledError {
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label: "ERROR from plugin".into(),
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msg: "error message pointing to call head span".into(),
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span: Some(call.head),
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})
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}
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}
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