nushell/crates/nu-command/src/strings/mod.rs

mod char_;
mod detect_columns;
mod encode_decode;
mod parse;
mod size;
mod split;
mod str_;

pub use char_::Char;
pub use detect_columns::*;
pub use encode_decode::*;
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)
}