Shows e-exprs inside container literals, delimited END (#186)

* Shows e-exprs inside container literals, delimited END
* Improves rendering of eexps, arg groups, comments
* Upgrade ion-rs to rc.11

Author: zslayton

Cargo.lock

@@ -21,7 +21,7 @@ flate2 = "1.0"
 infer = "0.15.0"
 # ion-rs version must be pinned because we are using experimental features
 # See https://github.com/amazon-ion/ion-cli/issues/155
-ion-rs = { version = "1.0.0-rc.10", features = ["experimental", "experimental-ion-hash"] }
+ion-rs = { version = "1.0.0-rc.11", features = ["experimental", "experimental-ion-hash"] }
 tempfile = "3.2.0"
 ion-schema = "0.15.0"
 lowcharts = "0.5.8"

Cargo.toml

@@ -105,7 +105,7 @@ impl<'a> CodeGenerator<'a, JavaLanguage> {
     }
 }
 
-impl<'a, L: Language + 'static> CodeGenerator<'a, L> {
+impl<L: Language + 'static> CodeGenerator<'_, L> {
     /// A [tera] filter that converts given tera string value to [upper camel case].
     /// Returns error if the given value is not a string.
     ///

src/bin/ion/commands/generate/generator.rs

@@ -6,6 +6,7 @@ use ion_rs::ion_hash::IonHasher;
 use ion_rs::*;
 use sha2::{Sha256, Sha512};
 use sha3::{Sha3_256, Sha3_512};
+use std::fmt;
 use std::io::Write;
 
 // Macro to eliminate repetitive code for each hash algorithm.
@@ -109,8 +110,14 @@ impl IonCliCommand for HashCommand {
                 for elem in reader.elements() {
                     let elem = elem?;
                     let digest = hasher.hash_it(&elem)?;
-                    let digest_string: String =
-                        digest.iter().map(|b| format!("{:02x?}", b)).collect();
+                    let digest_string = digest.iter().fold(
+                        String::with_capacity(digest.len() * 2),
+                        |mut string, byte| {
+                            use fmt::Write;
+                            write!(&mut string, "{:02x}", byte).expect("infallible");
+                            string
+                        },
+                    );
                     output.write_all(digest_string.as_bytes())?;
                     output.write_all("\n".as_bytes())?;
                 }