Remove unwraps (#1153)

* Remove a batch of unwraps

* finish another batch

crates/nu-parser/src/hir/tokens_iterator/debug/expand_trace.rs

@@ -254,7 +254,7 @@ pub struct ExpandTracer {
 
 impl ExpandTracer {
     pub fn print(&self, source: Text) -> PrintTracer {
-        let root = self.frame_stack.get(0).unwrap().to_tree_frame(&source);
+        let root = self.frame_stack[0].to_tree_frame(&source);
 
         PrintTracer { root, source }
     }

crates/nu-parser/src/parse/operator.rs

@@ -42,7 +42,11 @@ impl CompareOperator {
 
 impl From<&str> for CompareOperator {
     fn from(input: &str) -> CompareOperator {
-        CompareOperator::from_str(input).unwrap()
+        if let Ok(output) = CompareOperator::from_str(input) {
+            output
+        } else {
+            unreachable!("Internal error: CompareOperator from failed")
+        }
     }
 }
 
@@ -90,7 +94,11 @@ impl EvaluationOperator {
 
 impl From<&str> for EvaluationOperator {
     fn from(input: &str) -> EvaluationOperator {
-        EvaluationOperator::from_str(input).unwrap()
+        if let Ok(output) = EvaluationOperator::from_str(input) {
+            output
+        } else {
+            unreachable!("Internal error: EvaluationOperator 'from' failed")
+        }
     }
 }
 

crates/nu-parser/src/parse/parser.rs

@@ -148,13 +148,21 @@ macro_rules! primitive_decimal {
         $(
             impl From<$ty> for Number {
                 fn from(decimal: $ty) -> Number {
-                    Number::Decimal(BigDecimal::$from(decimal).unwrap())
+                    if let Some(num) = BigDecimal::$from(decimal) {
+                        Number::Decimal(num)
+                    } else {
+                        unreachable!("Internal error: BigDecimal 'from' failed")
+                    }
                 }
             }
 
             impl From<&$ty> for Number {
                 fn from(decimal: &$ty) -> Number {
-                    Number::Decimal(BigDecimal::$from(*decimal).unwrap())
+                    if let Some(num) = BigDecimal::$from(*decimal) {
+                        Number::Decimal(num)
+                    } else {
+                        unreachable!("Internal error: BigDecimal 'from' failed")
+                    }
                 }
             }
         )*
@@ -909,11 +917,13 @@ pub fn module(input: NomSpan) -> IResult<NomSpan, TokenNode> {
 }
 
 fn parse_int<T>(frag: &str, neg: Option<T>) -> i64 {
-    let int = FromStr::from_str(frag).unwrap();
-
-    match neg {
-        None => int,
-        Some(_) => -int,
+    if let Ok(int) = FromStr::from_str(frag) {
+        match neg {
+            None => int,
+            Some(_) => -int,
+        }
+    } else {
+        unreachable!("Internal error: parse_int failed");
     }
 }
 

crates/nu-parser/src/parse/token_tree_builder.rs

@@ -323,10 +323,13 @@ impl TokenTreeBuilder {
 
         let mut input = input.into_iter();
 
-        let head = input.next().unwrap();
-        let tail = input.collect();
+        if let Some(head) = input.next() {
+            let tail = input.collect();
 
-        CallNode::new(Box::new(head), tail).spanned(span.into())
+            CallNode::new(Box::new(head), tail).spanned(span.into())
+        } else {
+            unreachable!("Internal error: spanned_call failed")
+        }
     }
 
     fn consume_delimiter(

crates/nu-parser/src/parse/tokens.rs

@@ -88,9 +88,19 @@ impl RawNumber {
 
     pub(crate) fn to_number(self, source: &Text) -> Number {
         match self {
-            RawNumber::Int(tag) => Number::Int(BigInt::from_str(tag.slice(source)).unwrap()),
+            RawNumber::Int(tag) => {
+                if let Ok(int) = BigInt::from_str(tag.slice(source)) {
+                    Number::Int(int)
+                } else {
+                    unreachable!("Internal error: to_number failed")
+                }
+            }
             RawNumber::Decimal(tag) => {
-                Number::Decimal(BigDecimal::from_str(tag.slice(source)).unwrap())
+                if let Ok(decimal) = BigDecimal::from_str(tag.slice(source)) {
+                    Number::Decimal(decimal)
+                } else {
+                    unreachable!("Internal error: to_number failed")
+                }
             }
         }
     }