nushell/crates/nu-command/src/strings/split/row.rs
Stefan Holderbach 438062d7fc
Document and critically review ShellError variants - Ep. 1 (#8229)
# Description

The `ShellError` enum at the moment is kind of messy. 

Many variants are basic tuple structs where you always have to reference
the implementation with its macro invocation to know which field serves
which purpose.
Furthermore we have both variants that are kind of redundant or either
overly broad to be useful for the user to match on or overly specific
with few uses.

So I set out to start fixing the lacking documentation and naming to
make it feasible to critically review the individual usages and fix
those.
Furthermore we can decide to join or split up variants that don't seem
to be fit for purpose.

Feel free to add review comments if you spot inconsistent use of
`ShellError` variants.

- Name fields on `ShellError::OperatorOverflow`
- Name fields on `ShellError::PipelineMismatch`
- Add doc to `ShellError::OnlySupportsThisInputType`
- Name `ShellError::OnlySupportsThisInputType`
- Name field on `ShellError::PipelineEmpty`
- Comment about issues with `TypeMismatch*`
- Fix a few `exp_input_type`s
- Name fields on `ShellError::InvalidRange`

# User-Facing Changes

(None now, end goal more explicit and consistent error messages)

# Tests + Formatting

(No additional tests needed so far)
2023-03-01 20:34:48 +01:00

158 lines
4.6 KiB
Rust

use nu_engine::CallExt;
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
Value,
};
#[derive(Clone)]
pub struct SubCommand;
impl Command for SubCommand {
fn name(&self) -> &str {
"split row"
}
fn signature(&self) -> Signature {
Signature::build("split row")
.input_output_types(vec![(Type::String, Type::List(Box::new(Type::String)))])
.vectorizes_over_list(true)
.required(
"separator",
SyntaxShape::String,
"the character that denotes what separates rows",
)
.named(
"number",
SyntaxShape::Int,
"Split into maximum number of items",
Some('n'),
)
.category(Category::Strings)
}
fn usage(&self) -> &str {
"Split a string into multiple rows using a separator."
}
fn search_terms(&self) -> Vec<&str> {
vec!["separate", "divide"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
split_row(engine_state, stack, call, input)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Split a string into rows of char",
example: "'abc' | split row ''",
result: Some(Value::List {
vals: vec![
Value::test_string(""),
Value::test_string("a"),
Value::test_string("b"),
Value::test_string("c"),
Value::test_string(""),
],
span: Span::test_data(),
}),
},
Example {
description: "Split a string into rows by the specified separator",
example: "'a--b--c' | split row '--'",
result: Some(Value::List {
vals: vec![
Value::test_string("a"),
Value::test_string("b"),
Value::test_string("c"),
],
span: Span::test_data(),
}),
},
Example {
description: "Split a string by '-'",
example: "'-a-b-c-' | split row '-'",
result: Some(Value::List {
vals: vec![
Value::test_string(""),
Value::test_string("a"),
Value::test_string("b"),
Value::test_string("c"),
Value::test_string(""),
],
span: Span::test_data(),
}),
},
]
}
}
fn split_row(
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let name_span = call.head;
let separator: Spanned<String> = call.req(engine_state, stack, 0)?;
let max_split: Option<usize> = call.get_flag(engine_state, stack, "number")?;
input.flat_map(
move |x| split_row_helper(&x, &separator, max_split, name_span),
engine_state.ctrlc.clone(),
)
}
fn split_row_helper(
v: &Value,
separator: &Spanned<String>,
max_split: Option<usize>,
name: Span,
) -> Vec<Value> {
match v.span() {
Ok(v_span) => {
if let Ok(s) = v.as_string() {
match max_split {
Some(max_split) => s
.splitn(max_split, &separator.item)
.map(|s| Value::string(s, v_span))
.collect(),
None => s
.split(&separator.item)
.map(|s| Value::string(s, v_span))
.collect(),
}
} else {
vec![Value::Error {
error: ShellError::PipelineMismatch {
exp_input_type: "string".into(),
dst_span: name,
src_span: v_span,
},
}]
}
}
Err(error) => vec![Value::Error { error }],
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(SubCommand {})
}
}