⚡ Bolt: Remove unnecessary String allocation in parser segments

compiler/rockql-parser/src/lib.rs

@@ -27,9 +27,16 @@ impl Display for Diagnostic {
     }
 }
 
+/// Represents a raw query segment before parsing.
+///
+/// ⚡ Bolt Optimization:
+/// Previously `Segment` stored `text: String`, causing an allocation for every segment
+/// split by a pipe. By storing a reference to the original source string (`&'a str`),
+/// we eliminate multiple heap allocations per parsed query, reducing memory usage
+/// and speeding up parsing of pipelines.
 #[derive(Debug)]
-struct Segment {
-    text: String,
+struct Segment<'a> {
+    text: &'a str,
     span: Span,
 }
 
@@ -47,7 +54,7 @@ pub fn parse(source: &str) -> Result<Query, Vec<Diagnostic>> {
     let mut diagnostics = Vec::new();
 
     for segment in segments {
-        match parse_transform(&segment.text, segment.span) {
+        match parse_transform(segment.text, segment.span) {
             Ok(transform) => transforms.push(SpannedTransform::new(segment.span, transform)),
             Err(diagnostic) => diagnostics.push(diagnostic),
         }
@@ -64,7 +71,7 @@ pub fn format_source(source: &str) -> Result<String, Vec<Diagnostic>> {
     parse(source).map(|query| format!("{query}\n"))
 }
 
-fn split_segments(source: &str) -> Vec<Segment> {
+fn split_segments<'a>(source: &'a str) -> Vec<Segment<'a>> {
     let mut segments = Vec::new();
 
     for (line_index, line) in source.lines().enumerate() {
@@ -88,15 +95,15 @@ fn split_segments(source: &str) -> Vec<Segment> {
     segments
 }
 
-fn push_segment(segments: &mut Vec<Segment>, raw: &str, line: usize, byte_start: usize) {
+fn push_segment<'a>(segments: &mut Vec<Segment<'a>>, raw: &'a str, line: usize, byte_start: usize) {
     let text = raw.trim();
     if text.is_empty() {
         return;
     }
 
     let leading_bytes = raw.find(text).unwrap_or(0);
     segments.push(Segment {
-        text: text.to_owned(),
+        text,
         span: Span::new(line, byte_start + leading_bytes + 1),
     });
 }