chore: add examples to print IR for some PromQL and SQL queries

crates/lower/examples/topk_ir.rs

@@ -0,0 +1,185 @@
+// cargo run -p asap-control-lower --example topk_ir
+//
+// Lowers every topk-shaped query from the design discussion and prints the
+// resulting L3 IR. Used for interactive exploration; not a test.
+
+use asap_control_core::intent_algebra::schema::{Column, DataType, Schema};
+use asap_control_core::types::AccuracyTarget;
+use asap_control_lower::{lower_promql, lower_sql, SqlCatalog};
+
+fn col(name: &str, dtype: DataType) -> Column {
+    Column::new(name, dtype, false)
+}
+
+fn catalog() -> SqlCatalog {
+    SqlCatalog::new()
+        .with_table(
+            "metrics",
+            Schema::with_time_index(
+                vec![
+                    col("ts", DataType::Timestamp),
+                    col("service", DataType::Utf8),
+                    col("region", DataType::Utf8),
+                    col("latency", DataType::Float64),
+                    col("bytes", DataType::Int64),
+                ],
+                0,
+                vec![],
+            ),
+        )
+        .with_table(
+            "hosts",
+            Schema::new(vec![
+                col("service", DataType::Utf8),
+                col("region", DataType::Utf8),
+            ]),
+        )
+}
+
+async fn show_sql(label: &str, query: &str) {
+    println!("━━━ {label} ━━━");
+    println!("{query}");
+    match lower_sql(query, &catalog(), AccuracyTarget::Exact).await {
+        Ok(qe) => println!("{qe:#?}"),
+        Err(e) => println!("ERR: {e}"),
+    }
+    println!();
+}
+
+fn show_promql(label: &str, query: &str) {
+    println!("━━━ {label} ━━━");
+    println!("{query}");
+    match lower_promql(query, AccuracyTarget::Exact) {
+        Ok(qe) => println!("{qe:#?}"),
+        Err(e) => println!("ERR: {e}"),
+    }
+    println!();
+}
+
+#[tokio::main]
+async fn main() {
+    // ── SQL ──────────────────────────────────────────────────────────────────
+
+    show_sql(
+        "S1 — count ranked, alias",
+        "SELECT service, COUNT(*) AS cnt \
+         FROM metrics GROUP BY service \
+         ORDER BY cnt DESC LIMIT 5",
+    )
+    .await;
+
+    show_sql(
+        "S2 — count ranked, inline",
+        "SELECT service, COUNT(*) \
+         FROM metrics GROUP BY service \
+         ORDER BY COUNT(*) DESC LIMIT 5",
+    )
+    .await;
+
+    show_sql(
+        "S3 — count ranked, with OFFSET",
+        "SELECT service, COUNT(*) AS cnt \
+         FROM metrics GROUP BY service \
+         ORDER BY cnt DESC LIMIT 5 OFFSET 10",
+    )
+    .await;
+
+    show_sql(
+        "S4 — SUM ranked",
+        "SELECT service, SUM(bytes) AS total \
+         FROM metrics GROUP BY service \
+         ORDER BY total DESC LIMIT 5",
+    )
+    .await;
+
+    show_sql(
+        "S5 — AVG ranked",
+        "SELECT service, AVG(latency) AS avg_lat \
+         FROM metrics GROUP BY service \
+         ORDER BY avg_lat DESC LIMIT 5",
+    )
+    .await;
+
+    show_sql(
+        "S6 — MAX ranked",
+        "SELECT service, MAX(latency) AS max_lat \
+         FROM metrics GROUP BY service \
+         ORDER BY max_lat DESC LIMIT 5",
+    )
+    .await;
+
+    show_sql(
+        "S7 — no aggregation",
+        "SELECT ts, service, latency \
+         FROM metrics \
+         ORDER BY latency DESC LIMIT 5",
+    )
+    .await;
+
+    show_sql(
+        "S8 — partitioned count topk (window function)",
+        "SELECT service, region, cnt FROM (\
+            SELECT service, region, COUNT(*) AS cnt, \
+                   ROW_NUMBER() OVER (PARTITION BY region ORDER BY COUNT(*) DESC) AS rn \
+            FROM metrics GROUP BY service, region\
+         ) t WHERE rn <= 5",
+    )
+    .await;
+
+    show_sql(
+        "S9 — partitioned AVG topk (window function)",
+        "SELECT service, region, avg_lat FROM (\
+            SELECT service, region, AVG(latency) AS avg_lat, \
+                   ROW_NUMBER() OVER (PARTITION BY region ORDER BY AVG(latency) DESC) AS rn \
+            FROM metrics GROUP BY service, region\
+         ) t WHERE rn <= 5",
+    )
+    .await;
+
+    // ── PromQL ───────────────────────────────────────────────────────────────
+
+    show_promql(
+        "P1 — topk over count_over_time",
+        "topk(5, count_over_time(http_requests_total[5m]))",
+    );
+
+    show_promql(
+        "P2 — topk over instant vector",
+        "topk(5, http_requests_total)",
+    );
+
+    show_promql(
+        "P3 — topk over rate",
+        "topk(5, rate(http_requests_total[5m]))",
+    );
+
+    show_promql(
+        "P4 — topk over avg_over_time",
+        "topk(5, avg_over_time(http_requests_total[5m]))",
+    );
+
+    show_promql(
+        "P5 — topk over sum-by aggregation",
+        "topk(5, sum by (service) (http_requests_total))",
+    );
+
+    show_promql(
+        "P6 — bottomk over instant vector",
+        "bottomk(5, http_requests_total)",
+    );
+
+    show_promql(
+        "P8 — topk with by, instant vector",
+        "topk by (service) (5, http_requests_total)",
+    );
+
+    show_promql(
+        "P9 — topk with by, over rate",
+        "topk by (service) (5, rate(http_requests_total[5m]))",
+    );
+
+    show_promql(
+        "P10 — topk with by, over count_over_time",
+        "topk by (service) (5, count_over_time(http_requests_total[5m]))",
+    );
+}