rulemorph 0.3.1

use super::*;

mod mutation;

pub(super) use mutation::{eval_pad, eval_replace, eval_split};

pub(super) fn eval_unary_string_op<F>(
    args: &[Expr],
    injected: Option<&EvalValue>,
    record: &JsonValue,
    context: Option<&JsonValue>,
    out: &JsonValue,
    base_path: &str,
    locals: Option<&EvalLocals<'_>>,
    op: F,
) -> Result<EvalValue, TransformError>
where
    F: FnOnce(&JsonValue, &str) -> Result<JsonValue, TransformError>,
{
    let total_len = args_len(args, injected);
    if total_len != 1 {
        return Err(TransformError::new(
            TransformErrorKind::ExprError,
            "expr.args must contain exactly one item",
        )
        .with_path(format!("{}.args", base_path)));
    }

    let arg_path = format!("{}.args[0]", base_path);
    let value = eval_expr_at_index(0, args, injected, record, context, out, base_path, locals)?;
    match value {
        EvalValue::Missing => Ok(EvalValue::Missing),
        EvalValue::Value(value) => {
            if value.is_null() {
                return Err(TransformError::new(
                    TransformErrorKind::ExprError,
                    "expr arg must not be null",
                )
                .with_path(arg_path));
            }
            op(&value, &arg_path).map(EvalValue::Value)
        }
    }
}