From 5613674d9320a27147366dbdbc3807319e7e6cfe Mon Sep 17 00:00:00 2001
From: Dmitry Dodzin <d.dodzin@gmail.com>
Date: Wed, 18 Jun 2025 20:22:42 +0300
Subject: [PATCH 1/2] Add pipe operator

---
 src/lib.rs            | 19 +++++++++++++++++++
 src/parser/jslt.pest  |  3 ++-
 src/transform/expr.rs |  9 +++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index 502f439..980417e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -230,6 +230,25 @@ mod tests {
     Ok(())
   }
 
+  #[test]
+  fn pipe_operator() -> Result<()> {
+    let jslt: Jslt = r#"
+    .menu.popup.menuitem | {
+      "result" : {
+        "Open" : .[0].onclick,
+        "Close" : .[1].onclick
+      }
+    }
+    "#
+    .parse()?;
+
+    let output = jslt.transform_value(&BASIC_INPUT)?;
+
+    assert_eq!(&output, BASIC_OUTPUT.deref());
+
+    Ok(())
+  }
+
   #[test]
   fn object_for() -> Result<()> {
     let jslt: Jslt = r#"
diff --git a/src/parser/jslt.pest b/src/parser/jslt.pest
index 6dc5afc..8788551 100644
--- a/src/parser/jslt.pest
+++ b/src/parser/jslt.pest
@@ -6,7 +6,7 @@ Expr = _{ OperatorExpr | ValueExpr }
 ValueExpr = _{ VariableDef | FunctionDef | IfStatement | Value }
 OperatorExpr = { ValueExpr ~ (Operator ~ ValueExpr)+ }
 
-Operator = _{ Add | Sub | Div | Mul | Gte | Gt | Lte | Lt | And | Or | Equal | NotEqual }
+Operator = _{ Add | Sub | Div | Mul | Gte | Gt | Lte | Lt | And | Or | Equal | NotEqual | Pipe }
 
 Add = { "+" }
 Sub = { "-" }
@@ -20,6 +20,7 @@ Equal = { "==" }
 NotEqual = { "!=" }
 And = { "and" }
 Or = { "or" }
+Pipe = { "|" }
 If = _{ "if" }
 For = _{ "for" }
 Def = _{ "def" }
diff --git a/src/transform/expr.rs b/src/transform/expr.rs
index 259ba87..a941d9e 100644
--- a/src/transform/expr.rs
+++ b/src/transform/expr.rs
@@ -92,6 +92,7 @@ pub enum OperatorTransformer {
   Lte,
   Equal,
   NotEqual,
+  Pipe,
 }
 
 impl fmt::Display for OperatorTransformer {
@@ -109,6 +110,7 @@ impl fmt::Display for OperatorTransformer {
       OperatorTransformer::Lte => f.write_str("<="),
       OperatorTransformer::Equal => f.write_str("=="),
       OperatorTransformer::NotEqual => f.write_str("!="),
+      OperatorTransformer::Pipe => f.write_str("|"),
     }
   }
 }
@@ -172,6 +174,7 @@ impl OperatorExprTransformer {
     impl_operator_parse!(pairs, Sub);
     impl_operator_parse!(pairs, Mul);
     impl_operator_parse!(pairs, Div);
+    impl_operator_parse!(pairs, Pipe);
 
     Err(JsltError::InvalidInput(format!(
       "Could not evaluate the expession {pairs:#?}",
@@ -192,6 +195,11 @@ impl Transform for OperatorExprTransformer {
     let left = self
       .lhs
       .transform_value(Context::Borrowed(&context), input)?;
+
+    if matches!(self.operator, OperatorTransformer::Pipe) {
+      return self.rhs.transform_value(context, &left);
+    }
+
     let right = self.rhs.transform_value(context, input)?;
 
     match self.operator {
@@ -386,6 +394,7 @@ impl Transform for OperatorExprTransformer {
       },
       OperatorTransformer::Equal => Ok(Value::Bool(left == right)),
       OperatorTransformer::NotEqual => Ok(Value::Bool(left != right)),
+      OperatorTransformer::Pipe => unreachable!(),
     }
   }
 }

From 0cb21f9afaca48b6d2692f57602ff84e592313aa Mon Sep 17 00:00:00 2001
From: Dmitry Dodzin <d.dodzin@gmail.com>
Date: Wed, 18 Jun 2025 20:27:35 +0300
Subject: [PATCH 2/2] make test double pipe

---
 src/lib.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 980417e..c94dd65 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -234,10 +234,10 @@ mod tests {
   fn pipe_operator() -> Result<()> {
     let jslt: Jslt = r#"
     .menu.popup.menuitem | {
-      "result" : {
-        "Open" : .[0].onclick,
-        "Close" : .[1].onclick
-      }
+      "Open" : .[0].onclick,
+      "Close" : .[1].onclick
+    } | {
+      "result" : .
     }
     "#
     .parse()?;