From 367241421222a2d9a0462f0a871770c48c3d5975 Mon Sep 17 00:00:00 2001 From: torkleyy Date: Wed, 20 Dec 2017 17:37:12 +0100 Subject: [PATCH] Simplify and fix code --- src/engine.rs | 225 +++++++++++++------------------------------------- 1 file changed, 57 insertions(+), 168 deletions(-) diff --git a/src/engine.rs b/src/engine.rs index 4ecda460..43c8137d 100644 --- a/src/engine.rs +++ b/src/engine.rs @@ -230,6 +230,37 @@ impl Engine { } } + fn search_scope<'a, F, T>( + scope: &'a mut Scope, + id: &str, + map: F, + ) -> Result<(usize, T), EvalAltResult> + where + F: FnOnce(&'a mut Box) -> Result, + { + scope + .iter_mut() + .enumerate() + .rev() + .find(|&(_, &mut (ref name, _))| *id == *name) + .ok_or_else(|| EvalAltResult::ErrorVariableNotFound(id.to_owned())) + .and_then(move |(idx, &mut (_, ref mut val))| map(val).map(|val| (idx, val))) + } + + fn array_value(&self, scope: &mut Scope, id: &str, idx: &Expr) -> Result<(usize, usize, Box), EvalAltResult> { + let idx_boxed = self.eval_expr(scope, idx)? + .downcast::() + .map_err(|_| EvalAltResult::ErrorIndexMismatch)?; + let idx = *idx_boxed as usize; + let (idx_sc, val) = Self::search_scope(scope, id, |val| { + ((*val).downcast_mut() as Option<&mut Vec>>) + .map(|arr| arr[idx].clone()) + .ok_or(EvalAltResult::ErrorIndexMismatch) + })?; + + Ok((idx_sc, idx, val)) + } + fn get_dot_val( &self, scope: &mut Scope, @@ -238,100 +269,24 @@ impl Engine { ) -> Result, EvalAltResult> { match *dot_lhs { Expr::Identifier(ref id) => { - scope - .iter_mut() - .rev() - .find(|&&mut (ref name, _)| *id == *name) - .map(|&mut (_, ref mut val)| val.clone()) - .ok_or_else(|| EvalAltResult::ErrorVariableNotFound(id.clone())) - .and_then(|mut target| self.get_dot_val_helper(scope, &mut target, dot_rhs)) + let (sc_idx, mut target) = Self::search_scope(scope, id, |x| Ok(x.clone()))?; + let value = self.get_dot_val_helper(scope, &mut target, dot_rhs); - // let mut target: Option> = None; - // - // for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - // if *id == *name { - // target = val.as_ref().box_clone(); - // break; - // } - // } - // - // if let Some(mut t) = target { - // let result = self.get_dot_val_helper(scope, &mut t, dot_rhs); - // - // for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - // if *id == *name { - // *val = t; - // break; - // } - // } - // return result; - // } - // - // Err(EvalAltResult::ErrorVariableNotFound(id.clone())) + // In case the expression mutated `target`, we need to reassign it because + // of the above `clone`. + scope[sc_idx].1 = target; + + value } Expr::Index(ref id, ref idx_raw) => { - let idx_boxed = self.eval_expr(scope, idx_raw)?; + let (sc_idx, idx, mut target) = self.array_value(scope, id, idx_raw)?; + let value = self.get_dot_val_helper(scope, &mut target, dot_rhs); - scope - .iter_mut() - .rev() - .find(|&&mut (ref name, _)| *id == *name) - .ok_or_else(|| EvalAltResult::ErrorVariableNotFound(id.clone())) - .and_then(|&mut (_, ref mut val)| { - ((*val).downcast_mut() as Option<&mut Vec>>) - .and_then(|arr| { - idx_boxed - .downcast_ref::() - .map(|idx| arr[*idx as usize].clone()) - }) - .ok_or(EvalAltResult::ErrorIndexMismatch) - }) - .and_then(|mut target| self.get_dot_val_helper(scope, &mut target, dot_rhs)) + // In case the expression mutated `target`, we need to reassign it because + // of the above `clone`. + scope[sc_idx].1.downcast_mut::>>().unwrap()[idx] = target; - // let mut target: Option> = None; - // - // for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - // if *id == *name { - // if let Some(arr_typed) = (*val).downcast_mut() as Option<&mut Vec>> - // { - // let result = self.call_fn( - // "clone", - // Some(&mut arr_typed[*idx as usize]), - // None, - // None, - // None, - // None, - // None, - // ); - // - // if let Ok(clone) = result { - // target = Some(clone); - // break; - // } else { - // return result; - // } - // } else { - // return Err(EvalAltResult::ErrorIndexMismatch); - // } - // } - // } - // - // if let Some(mut t) = target { - // let result = self.get_dot_val_helper(scope, &mut t, dot_rhs); - // for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - // if *id == *name { - // if let Some(arr_typed) = - // (*val).downcast_mut() as Option<&mut Vec>> - // { - // arr_typed[*idx as usize] = t; - // break; - // } - // } - // } - // return result; - // } - // - // Err(EvalAltResult::ErrorVariableNotFound(id.clone())) + value } _ => Err(EvalAltResult::InternalErrorMalformedDotExpression), } @@ -374,72 +329,24 @@ impl Engine { ) -> Result, EvalAltResult> { match *dot_lhs { Expr::Identifier(ref id) => { - let mut target: Option> = None; + let (sc_idx, mut target) = Self::search_scope(scope, id, |x| Ok(x.clone()))?; + let value = self.set_dot_val_helper(&mut target, dot_rhs, source_val); - for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - if *id == *name { - target = Some(val.clone()) - } - } + // In case the expression mutated `target`, we need to reassign it because + // of the above `clone`. + scope[sc_idx].1 = target; - if let Some(mut t) = target { - let result = self.set_dot_val_helper(&mut t, dot_rhs, source_val); - - for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - if *id == *name { - *val = t; - break; - } - } - return result; - } - - Err(EvalAltResult::ErrorAssignmentToUnknownLHS) + value } Expr::Index(ref id, ref idx_raw) => { - let idx_boxed = self.eval_expr(scope, idx_raw)?; - let idx = if let Some(i) = idx_boxed.downcast_ref::() { - *i as usize - } else { - return Err(EvalAltResult::ErrorIndexMismatch); - }; + let (sc_idx, idx, mut target) = self.array_value(scope, id, idx_raw)?; + let value = self.set_dot_val_helper(&mut target, dot_rhs, source_val); - let mut target: Option> = None; + // In case the expression mutated `target`, we need to reassign it because + // of the above `clone`. + scope[sc_idx].1.downcast_mut::>>().unwrap()[idx] = target; - for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - if *id == *name { - if let Some(arr_typed) = (*val).downcast_mut() as Option<&mut Vec>> - { - let result = Ok(arr_typed[idx].clone()); - - if let Ok(clone) = result { - target = Some(clone); - break; - } else { - return result; - } - } else { - return Err(EvalAltResult::ErrorIndexMismatch); - } - } - } - - if let Some(mut t) = target { - let result = self.set_dot_val_helper(&mut t, dot_rhs, source_val); - for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - if *id == *name { - if let Some(arr_typed) = - (*val).downcast_mut() as Option<&mut Vec>> - { - arr_typed[idx] = t; - break; - } - } - } - return result; - } - - Err(EvalAltResult::ErrorVariableNotFound(id.clone())) + value } _ => Err(EvalAltResult::InternalErrorMalformedDotExpression), } @@ -460,25 +367,7 @@ impl Engine { Err(EvalAltResult::ErrorVariableNotFound(id.clone())) } Expr::Index(ref id, ref idx_raw) => { - let idx = self.eval_expr(scope, idx_raw)?; - - for &mut (ref name, ref mut val) in &mut scope.iter_mut().rev() { - if *id == *name { - if let Some(i) = idx.downcast_ref::() { - if let Some(arr_typed) = - (*val).downcast_mut() as Option<&mut Vec>> - { - return Ok(arr_typed[*i as usize].clone()); - } else { - return Err(EvalAltResult::ErrorIndexMismatch); - } - } else { - return Err(EvalAltResult::ErrorIndexMismatch); - } - } - } - - Err(EvalAltResult::ErrorVariableNotFound(id.clone())) + self.array_value(scope, id, idx_raw).map(|(_, _, x)| x) } Expr::Assignment(ref id, ref rhs) => { let rhs_val = self.eval_expr(scope, rhs)?;