new: object flattening feature

Cargo.toml

@@ -4,7 +4,7 @@ members = [".", "crate/encstr"]
 [workspace.package]
 repository = "https://github.com/pamburus/hl"
 authors = ["Pavel Ivanov <[email protected]>"]
-version = "0.28.2-alpha.2"
+version = "0.29.0-alpha.1"
 edition = "2021"
 license = "MIT"
 
@@ -95,6 +95,7 @@ wildmatch = "2"
 [profile.release]
 debug = false
 opt-level = 3
+inline-threshold = 500
 codegen-units = 1
 lto = true
 

README.md

@@ -488,6 +488,7 @@ Output Options:
       --no-raw                Disable raw source messages output, overrides --raw option
       --raw-fields            Output field values as is, without unescaping or prettifying
   -h, --hide <KEY>            Hide or reveal fields with the specified keys, prefix with ! to reveal, specify '!*' to reveal all
+      --flatten <WHEN>        Whether to flatten objects [default: always] [possible values: never, always]
   -t, --time-format <FORMAT>  Time format, see https://man7.org/linux/man-pages/man1/date.1.html [env: HL_TIME_FORMAT=] [default: "%b %d %T.%3N"]
   -Z, --time-zone <TZ>        Time zone name, see column "TZ identifier" at https://en.wikipedia.org/wiki/List_of_tz_database_time_zones [env: HL_TIME_ZONE=] [default: UTC]
   -L, --local                 Use local time zone, overrides --time-zone option

src/app.rs

@@ -74,6 +74,7 @@ pub struct Options {
     pub tail: u64,
     pub delimiter: Delimiter,
     pub unix_ts_unit: Option<UnixTimestampUnit>,
+    pub flatten: bool,
 }
 
 impl Options {
@@ -639,7 +640,8 @@ impl App {
                     self.options.fields.filter.clone(),
                     self.options.formatting.clone(),
                 )
-                .with_field_unescaping(!self.options.raw_fields),
+                .with_field_unescaping(!self.options.raw_fields)
+                .with_flatten(self.options.flatten),
             )
         }
     }

src/cli.rs

@@ -153,6 +153,17 @@ pub struct Opt {
     )]
     pub hide: Vec<String>,
 
+    /// Whether to flatten objects.
+    #[arg(
+        long,
+        value_name = "WHEN",
+        value_enum,
+        default_value = "always",
+        overrides_with = "flatten",
+        help_heading = heading::OUTPUT
+    )]
+    pub flatten: FlattenOption,
+
     /// Time format, see https://man7.org/linux/man-pages/man1/date.1.html.
     #[arg(
         short,
@@ -360,6 +371,12 @@ pub enum UnixTimestampUnit {
     Ns,
 }
 
+#[derive(ValueEnum, Debug, Clone, Copy, PartialEq, Eq)]
+pub enum FlattenOption {
+    Never,
+    Always,
+}
+
 mod heading {
     pub const FILTERING: &str = "Filtering Options";
     pub const INPUT: &str = "Input Options";