From ad2b646700ee3735c936c368c57254e9cd9b5276 Mon Sep 17 00:00:00 2001
From: Thom Chiovoloni <tchiovoloni@mozilla.com>
Date: Wed, 27 Jun 2018 18:54:28 -0700
Subject: [PATCH] Remove regex dependency from query_sql. Fixes #771.

---
 query-sql/Cargo.toml |  1 -
 query-sql/src/lib.rs | 28 ++++++++++++++++++++--------
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/query-sql/Cargo.toml b/query-sql/Cargo.toml
index 583612e2..72cfaee5 100644
--- a/query-sql/Cargo.toml
+++ b/query-sql/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.1"
 workspace = ".."
 
 [dependencies]
-regex = "0.2"
 
 [dependencies.mentat_core]
 path = "../core"
diff --git a/query-sql/src/lib.rs b/query-sql/src/lib.rs
index 47a1655c..32a9ae60 100644
--- a/query-sql/src/lib.rs
+++ b/query-sql/src/lib.rs
@@ -8,7 +8,6 @@
 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
 // specific language governing permissions and limitations under the License.
 
-extern crate regex;
 #[macro_use] extern crate mentat_core;
 extern crate mentat_query;
 extern crate mentat_query_algebrizer;
@@ -559,15 +558,21 @@ impl QueryFragment for FromClause {
     }
 }
 
+/// `var` is something like `?foo99-people`.
+/// Trim the `?` and escape the rest. Prepend `i` to distinguish from
+/// the inline value space `v`.
+fn format_select_var(var: &str) -> String {
+    use std::iter::once;
+    let without_question = var.split_at(1).1;
+    let replaced_iter = without_question.chars().map(|c|
+        if c.is_ascii_alphanumeric() { c } else { '_' });
+    // Prefix with `i` (Avoiding this copy is probably not worth the trouble but whatever).
+    once('i').chain(replaced_iter).collect()
+}
+
 impl SelectQuery {
     fn push_variable_param(&self, var: &Variable, out: &mut QueryBuilder) -> BuildQueryResult {
-        // `var` is something like `?foo99-people`.
-        // Trim the `?` and escape the rest. Prepend `i` to distinguish from
-        // the inline value space `v`.
-        let re = regex::Regex::new("[^a-zA-Z_0-9]").unwrap();
-        let without_question = var.as_str().split_at(1).1;
-        let replaced = re.replace_all(without_question, "_");
-        let bind_param = format!("i{}", replaced);                 // We _could_ avoid this copying.
+        let bind_param = format_select_var(var.as_str());
         out.push_bind_param(bind_param.as_str())
     }
 }
@@ -817,4 +822,11 @@ mod tests {
         assert!(args.is_empty());
 
     }
+
+    #[test]
+    fn test_format_select_var() {
+        assert_eq!(format_select_var("?foo99-people"), "ifoo99_people");
+        assert_eq!(format_select_var("?FOO99-pëople.123"), "iFOO99_p_ople_123");
+        assert_eq!(format_select_var("?foo①bar越"), "ifoo_bar_");
+    }
 }