Add compiled query engine with selective and event input

Makefile

@@ -184,6 +184,10 @@ bench: ## Run benchmarks
 bench-parser: ## Run parser-only benchmark
 	$(DUNE) exec benchmarks/bench_parser.exe
 
+.PHONY: bench-execution
+bench-execution: ## Compare prepared execution with the interpreter in-process
+	$(DUNE) exec --root . --profile=release benchmarks/bench_execution.exe
+
 .PHONY: release
 release: ## Create a new release (usage: make release VERSION=1.2.3)
 	@if [ -z "$(VERSION)" ]; then \

README.md

@@ -148,6 +148,7 @@ Arguments:
 
 Options:
   -r, --raw-output    Output strings without quotes
+  --stream-output     Flush each result as it is produced
   --no-color          Disable colored output
   --repl              Start interactive REPL mode
   -v, --verbose       Show verbose output including deprecation warnings
@@ -156,6 +157,24 @@ Options:
   --help              Print help
 ```
 
+By default, all output is written at once after the query succeeds, and an
+error shares stdout with any results. With `--stream-output`, each result is
+flushed to stdout as it is produced. If a later result or input tail fails,
+earlier output on stdout remains, the error is written to stderr instead, and
+the process exits with status 1. Successful output is identical in both modes;
+a query with no results prints one empty line. This flag has no effect in REPL
+mode.
+
+Both modes execute complete items before EOF for supported root or direct
+root-member iteration; without `--stream-output` the results are held until the
+query has succeeded. Collection barriers, unsupported queries and `--debug`
+validate the complete JSON input first. After a query error, callbacks stop and input validation continues.
+A later input error wins. Invalid JSON also takes precedence over an invalid query.
+The debug AST prints only after valid EOF.
+For supported queries that start with a root object key, file, inline, and stdin
+input can retain only the selected value while validating the rest. Other queries
+retain the complete input. The JavaScript string entry remains validation-first.
+
 ## Contributing
 
 Contributions are welcome! See the [development setup](#development) below to get started.