chore: import upstream snapshot with attribution

examples/test_implicit_or_bug.rs

@@ -0,0 +1,132 @@
+//! Test to demonstrate the implicit OR bug in query parsing
+//!
+//! Run with: cargo run --example test_implicit_or_bug --features lex
+
+use memvid_core::{Memvid, PutOptions, SearchRequest};
+
+fn main() -> memvid_core::Result<()> {
+    let test_file = "/tmp/test_implicit.mv2";
+
+    // Clean up old file if exists
+    let _ = std::fs::remove_file(test_file);
+
+    println!("Creating test .mv2 file...");
+    let mut mem = Memvid::create(test_file)?;
+
+    // Add documents
+    println!("Adding test documents...");
+    mem.put_bytes_with_options(
+        b"I love machine learning",
+        PutOptions::builder().title("Doc 1").build(),
+    )?;
+    mem.put_bytes_with_options(
+        b"I love Python programming",
+        PutOptions::builder().title("Doc 2").build(),
+    )?;
+    mem.put_bytes_with_options(
+        b"Machine learning with Python is awesome",
+        PutOptions::builder().title("Doc 3").build(),
+    )?;
+    mem.commit()?;
+
+    println!();
+    println!("=== TESTING IMPLICIT OPERATOR BEHAVIOR ===");
+    println!("Query: 'machine python'");
+    println!();
+    println!("Expected behavior (AND): Should return 1 result");
+    println!("  - Only Doc 3 has BOTH 'machine' AND 'python'");
+    println!();
+    println!("Current behavior (OR): Returns 3 results");
+    println!("  - Any doc with 'machine' OR 'python'");
+    println!();
+
+    // Search with implicit operator
+    let results = mem.search(SearchRequest {
+        query: "machine python".to_string(),
+        top_k: 10,
+        snippet_chars: 200,
+        uri: None,
+        scope: None,
+        cursor: None,
+        #[cfg(feature = "temporal_track")]
+        temporal: None,
+        as_of_frame: None,
+        as_of_ts: None,
+        no_sketch: false,
+        acl_context: None,
+        acl_enforcement_mode: memvid_core::types::AclEnforcementMode::Audit,
+    })?;
+
+    println!("ACTUAL RESULTS: {} documents found", results.hits.len());
+    println!();
+
+    for (i, hit) in results.hits.iter().enumerate() {
+        let title = hit
+            .title
+            .as_ref()
+            .unwrap_or(&"Untitled".to_string())
+            .clone();
+        let text_lower = hit.text.to_lowercase();
+        let has_machine = text_lower.contains("machine");
+        let has_python = text_lower.contains("python");
+        let is_relevant = has_machine && has_python;
+
+        let status = if is_relevant {
+            "✓ RELEVANT"
+        } else {
+            "✗ NOT RELEVANT"
+        };
+
+        println!(
+            "  {}. {} [machine={}, python={}] {}",
+            i + 1,
+            title,
+            has_machine,
+            has_python,
+            status
+        );
+    }
+
+    println!();
+
+    // Calculate precision
+    let relevant_count = results
+        .hits
+        .iter()
+        .filter(|hit| {
+            let text = hit.text.to_lowercase();
+            text.contains("machine") && text.contains("python")
+        })
+        .count();
+
+    let precision = if results.hits.is_empty() {
+        0.0
+    } else {
+        (relevant_count as f64 / results.hits.len() as f64) * 100.0
+    };
+
+    println!(
+        "PRECISION: {:.1}% ({}/{} results are relevant)",
+        precision,
+        relevant_count,
+        results.hits.len()
+    );
+    println!();
+
+    // Verdict
+    if results.hits.len() == 1 && relevant_count == 1 {
+        println!("✓ CORRECT: Query uses implicit AND");
+        println!("  Perfect precision - returns only relevant docs");
+    } else if results.hits.len() > 1 {
+        println!("✗ BUG DETECTED: Query uses implicit OR");
+        println!("  Low precision - returns docs with EITHER term");
+        println!();
+    } else {
+        println!("? NO RESULTS: Check if lex feature is enabled");
+    }
+
+    // Cleanup
+    std::fs::remove_file(test_file)?;
+
+    Ok(())
+}