Stefan Holderbach f7b8f97873
Document and critically review ShellError variants - Ep. 2 (#8326)
Continuation of #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.

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

- Name fields of `SE::IncorrectValue`
- Merge and name fields on `SE::TypeMismatch`
- Name fields on `SE::UnsupportedOperator`
- Name fields on `AssignmentRequires*` and fix doc
- Name fields on `SE::UnknownOperator`
- Name fields on `SE::MissingParameter`
- Name fields on `SE::DelimiterError`
- Name fields on `SE::IncompatibleParametersSingle`

# User-Facing Changes

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

# Tests + Formatting

(No additional tests needed so far)
2023-03-06 11:31:07 +01:00

43 lines
1.4 KiB
Rust

mod char_;
mod detect_columns;
mod encode_decode;
mod format;
mod parse;
mod size;
mod split;
mod str_;
pub use char_::Char;
pub use detect_columns::*;
pub use encode_decode::*;
pub use format::*;
pub use parse::*;
pub use size::Size;
pub use split::*;
pub use str_::*;
use nu_protocol::{ast::Call, ShellError};
// For handling the grapheme_cluster related flags on some commands.
// This ensures the error messages are consistent.
pub fn grapheme_flags(call: &Call) -> Result<bool, ShellError> {
let g_flag = call.has_flag("grapheme-clusters");
// Check for the other flags and produce errors if they exist.
// Note that Nushell already prevents nonexistent flags from being used with commands,
// so this function can be reused for both the --utf-8-bytes commands and the --code-points commands.
if g_flag && call.has_flag("utf-8-bytes") {
Err(ShellError::IncompatibleParametersSingle {
msg: "Incompatible flags: --grapheme-clusters (-g) and --utf-8-bytes (-b)".to_string(),
span: call.head,
})?
}
if g_flag && call.has_flag("code-points") {
Err(ShellError::IncompatibleParametersSingle {
msg: "Incompatible flags: --grapheme-clusters (-g) and --utf-8-bytes (-b)".to_string(),
span: call.head,
})?
}
// Grapheme cluster usage is decided by the non-default -g flag
Ok(g_flag)
}