refactor(slice-safety): deny(clippy::indexing_slicing) + scoped escapes (#341)

src/curves/curve.rs

@@ -3,6 +3,12 @@
    Email: jb@taunais.com
    Date: 9/1/25
 ******************************************************************************/
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::curves::Point2D;
 use crate::curves::traits::StatisticalCurve;
 use crate::curves::utils::detect_peaks_and_valleys;

src/curves/traits.rs

@@ -3,6 +3,12 @@
    Email: jb@taunais.com
    Date: 23/2/25
 ******************************************************************************/
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::curves::{Curve, Point2D};
 use crate::error::{CurveError, OperationErrorKind};
 use crate::geometrics::{BasicMetrics, MetricsExtractor, RangeMetrics, ShapeMetrics, TrendMetrics};

src/curves/utils.rs

@@ -3,6 +3,12 @@
    Email: jb@taunais.com
    Date: 9/1/25
 ******************************************************************************/
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::curves::{Curve, Point2D};
 use crate::geometrics::GeometricObject;
 use rust_decimal::Decimal;

src/geometrics/interpolation/traits.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::error::InterpolationError;
 use crate::geometrics::{
     BiLinearInterpolation, CubicInterpolation, GeometricObject, InterpolationType,

src/lib.rs

@@ -1,5 +1,13 @@
 #![allow(unknown_lints)]
 #![allow(clippy::literal_string_with_formatting_args)]
+// Per rules/global_rules.md §Error Handling, unchecked `[]` / slicing is
+// banned in production code. Enforced crate-wide; individual modules that
+// need a transitional escape hatch carry a scoped `#![allow(..)]` with a
+// migration note (tracked as follow-ups to #341).
+#![deny(clippy::indexing_slicing)]
+// Unit and integration tests routinely index into `Vec`s they just pushed
+// into, so the lint is silenced in `#[cfg(test)]` only.
+#![cfg_attr(test, allow(clippy::indexing_slicing))]
 
 //! # OptionStratLib v0.16.0: Financial Options Library
 //!

src/model/axis.rs

@@ -131,13 +131,9 @@ impl Iterator for BasicAxisTypesIter {
     type Item = BasicAxisTypes;
 
     fn next(&mut self) -> Option<Self::Item> {
-        if self.index < BasicAxisTypes::VALUES.len() {
-            let value = BasicAxisTypes::VALUES[self.index];
-            self.index += 1;
-            Some(value)
-        } else {
-            None
-        }
+        let value = *BasicAxisTypes::VALUES.get(self.index)?;
+        self.index += 1;
+        Some(value)
     }
 }
 

src/model/option.rs

@@ -384,9 +384,16 @@ impl Options {
             side: &self.side,
         };
         let (asset_tree, option_tree) = generate_binomial_tree(&params)?;
+        let root = option_tree
+            .first()
+            .and_then(|row| row.first())
+            .copied()
+            .ok_or(PricingError::BinomialNodeMissing {
+                node: "option[0][0]",
+            })?;
         let price = match self.side {
-            Side::Long => option_tree[0][0],
-            Side::Short => -option_tree[0][0],
+            Side::Long => root,
+            Side::Short => -root,
         };
         Ok((price, asset_tree, option_tree))
     }

src/pricing/binomial_model.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::error::PricingError;
 use crate::model::types::{OptionStyle, OptionType, Side};
 use crate::pricing::payoff::{Payoff, PayoffInfo};

src/pricing/cliquet.rs

@@ -4,6 +4,12 @@
    Date: 13/01/26
 ******************************************************************************/
 
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 //! Cliquet option pricing module.
 //!
 //! Cliquet options (also known as ratchet options) consist of a series of

src/pricing/compound.rs

@@ -4,6 +4,12 @@
    Date: 13/01/26
 ******************************************************************************/
 
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 //! Compound option pricing module.
 //!
 //! Compound options are options on options (also called split-fee options).

src/pricing/telegraph.rs

@@ -3,6 +3,12 @@
    Email: jb@taunais.com
    Date: 19/8/24
 ******************************************************************************/
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 //! # Telegraph Process
 //!
 //! A Telegraph Process (also known as a two-state process) is a stochastic process

src/pricing/utils.rs

@@ -3,6 +3,12 @@
    Email: jb@taunais.com
    Date: 5/8/24
 ******************************************************************************/
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::Options;
 use crate::error::PricingError;
 use crate::error::decimal::DecimalError;

src/simulation/randomwalk.rs

@@ -4,6 +4,12 @@
    Date: 23/3/25
 ******************************************************************************/
 
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::error::PricingError;
 use crate::pricing::Profit;
 use crate::simulation::WalkParams;

src/simulation/simulator.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::Options;
 use crate::error::PricingError;
 use crate::pricing::Profit;

src/simulation/traits.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::backtesting::results::SimulationStatsResult;
 use crate::error::SimulationError;
 use crate::model::decimal::{decimal_normal_sample, finite_decimal};

src/strategies/base.rs

@@ -1,3 +1,7 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341.
+#![allow(clippy::indexing_slicing)]
+
 use crate::chains::OptionData;
 use crate::constants::{STRIKE_PRICE_LOWER_BOUND_MULTIPLIER, STRIKE_PRICE_UPPER_BOUND_MULTIPLIER};
 use crate::error::strategies::BreakEvenErrorKind;

src/strategies/bear_call_spread.rs

@@ -15,6 +15,12 @@ Key characteristics:
 - Also known as a vertical call credit spread
 */
 
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/bear_put_spread.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use positive::Positive;
 #[cfg(test)]
 use positive::pos_or_panic;

src/strategies/bull_call_spread.rs

@@ -14,6 +14,12 @@ Key characteristics:
 - Maximum profit achieved when price rises above higher strike
 - Also known as a vertical call debit spread
 */
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/bull_put_spread.rs

@@ -14,6 +14,12 @@ Key characteristics:
 - Maximum profit achieved when price stays above higher strike
 - Also known as a vertical put credit spread
 */
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/call_butterfly.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/custom.rs

@@ -3,6 +3,12 @@
    Email: jb@taunais.com
    Date: 2/10/24
 ******************************************************************************/
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/delta_neutral/model.rs

@@ -3,6 +3,12 @@
    Email: jb@taunais.com
    Date: 10/12/24
 ******************************************************************************/
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::adjustment::{AdjustmentConfig, AdjustmentPlan};
 use super::optimizer::AdjustmentOptimizer;
 use super::portfolio::{AdjustmentTarget, PortfolioGreeks};

src/strategies/delta_neutral/optimizer.rs

@@ -4,6 +4,12 @@
    Date: 24/12/25
 ******************************************************************************/
 
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 //! # Adjustment Optimizer Module
 //!
 //! Provides optimization algorithms for finding the best adjustment plan

src/strategies/graph.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use crate::pricing::Profit;
 use crate::strategies::base::BreakEvenable;
 use crate::strategies::{

src/strategies/iron_butterfly.rs

@@ -11,6 +11,12 @@ Key characteristics:
 - High probability of small profit
 - Requires very low volatility
 */
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/iron_condor.rs

@@ -9,6 +9,12 @@ Key characteristics:
 - Limited risk
 - Profit is highest when the underlying asset price remains between the two sold options at expiration
 */
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/long_butterfly_spread.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/long_call.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{BreakEvenable, Positionable, StrategyType};
 use crate::backtesting::results::{SimulationResult, SimulationStatsResult};
 use crate::chains::OptionChain;

src/strategies/long_put.rs

@@ -1,3 +1,9 @@
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{BreakEvenable, Positionable, StrategyType};
 use crate::backtesting::results::{SimulationResult, SimulationStatsResult};
 

src/strategies/long_straddle.rs

@@ -9,6 +9,12 @@ Key characteristics:
 - High cost due to purchasing both a call and a put
 - Profitable only with a large move in either direction
 */
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };

src/strategies/long_strangle.rs

@@ -9,6 +9,12 @@ Key characteristics:
 - Lower cost than a straddle
 - Requires a larger price move to become profitable
 */
+// Scoped allow: bulk migration of unchecked `[]` indexing to
+// `.get().ok_or_else(..)` tracked as follow-ups to #341. The existing
+// call sites are internal to this file and audited for invariant-bound
+// indices (fixed-length buffers, just-pushed slices, etc.).
+#![allow(clippy::indexing_slicing)]
+
 use super::base::{
     BreakEvenable, Optimizable, Positionable, Strategable, StrategyBasics, StrategyType, Validable,
 };