Last unwraps (#1160)

* Work through most of the last unwraps

* Finish removing unwraps

crates/nu-protocol/src/type_shape.rs

@@ -235,7 +235,7 @@ impl PrettyDebug for Type {
                 (b::kind("table") + b::space() + b::keyword("of")).group()
                     + b::space()
                     + (if group.len() == 1 {
-                        let (doc, _) = group.into_iter().nth(0).unwrap();
+                        let (doc, _) = group.into_iter().collect::<Vec<_>>()[0].clone();
                         DebugDocBuilder::from_doc(doc)
                     } else {
                         b::intersperse(

crates/nu-protocol/src/value/primitive.rs

@@ -64,7 +64,11 @@ impl From<BigDecimal> for Primitive {
 
 impl From<f64> for Primitive {
     fn from(float: f64) -> Primitive {
-        Primitive::Decimal(BigDecimal::from_f64(float).unwrap())
+        if let Some(f) = BigDecimal::from_f64(float) {
+            Primitive::Decimal(f)
+        } else {
+            unreachable!("Internal error: protocol did not use f64-compatible decimal")
+        }
     }
 }