From 1e3af751b7d92933126c8b7787f508139c832d69 Mon Sep 17 00:00:00 2001
From: Ziyang Hu <hu.ziyang@cantab.net>
Date: Wed, 18 May 2022 22:56:30 +0800
Subject: [PATCH] fn call notation

---
 src/data/eval.rs        |  6 ++++++
 src/data/expr_parser.rs | 25 ++++++++++++++++++-------
 src/grammar.pest        |  8 +++-----
 3 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/src/data/eval.rs b/src/data/eval.rs
index 9d65b35b..85a9d016 100644
--- a/src/data/eval.rs
+++ b/src/data/eval.rs
@@ -599,6 +599,12 @@ mod tests {
         dbg!(str2expr("switch 3 {2 => '2', 1+2 => '3', .. => 'x'}")?.partial_eval(&())?);
         dbg!(str2expr("null.is_null()")?.row_eval(&())?);
         dbg!(str2expr("null.is_null()")?.partial_eval(&())?);
+        dbg!(str2expr("null.not_null()")?.row_eval(&())?);
+        dbg!(str2expr("null.not_null()")?.partial_eval(&())?);
+        dbg!(str2expr("is_null(null)")?.row_eval(&())?);
+        dbg!(str2expr("is_null(null)")?.partial_eval(&())?);
+        dbg!(str2expr("is_null((null ~ 3)+2).is_null()")?.row_eval(&())?);
+        dbg!(str2expr("is_null((null ~ 3)+2).is_null()")?.partial_eval(&())?);
 
         Ok(())
     }
diff --git a/src/data/expr_parser.rs b/src/data/expr_parser.rs
index 69634165..d1c2ea41 100644
--- a/src/data/expr_parser.rs
+++ b/src/data/expr_parser.rs
@@ -86,6 +86,13 @@ fn build_cond_expr(pair: Pair) -> Result<Expr> {
     Ok(res)
 }
 
+fn build_call_expr(pair: Pair) -> Result<Expr> {
+    let mut pairs = pair.into_inner();
+    let method = get_method(pairs.next().unwrap().as_str());
+    let args = pairs.map(Expr::try_from).collect::<Result<Vec<_>>>()?;
+    Ok(Expr::Apply(method, args))
+}
+
 fn build_switch_expr(pair: Pair) -> Result<Expr> {
     let mut pairs = pair.into_inner();
     let expr = pairs.next().unwrap();
@@ -142,12 +149,7 @@ fn build_expr_primary(pair: Pair) -> Result<Expr> {
                     }
                     Rule::call => {
                         let mut pairs = p.into_inner();
-                        let method_name = pairs.next().unwrap().as_str();
-                        let op: Arc<dyn Op + Send + Sync> = match method_name {
-                            n if n == OpIsNull.name() => Arc::new(OpIsNull),
-                            n if n == OpNotNull.name() => Arc::new(OpNotNull),
-                            method_name => Arc::new(UnresolvedOp(method_name.to_string()))
-                        };
+                        let op: Arc<dyn Op + Send + Sync> = get_method(pairs.next().unwrap().as_str());
                         let mut args = vec![head];
                         args.extend(pairs.map(Expr::try_from).collect::<Result<Vec<_>>>()?);
                         head = Expr::Apply(op, args);
@@ -170,7 +172,8 @@ fn build_expr_primary(pair: Pair) -> Result<Expr> {
                 Rule::if_expr => return build_if_expr(p),
                 Rule::cond_expr => return build_cond_expr(p),
                 Rule::switch_expr => return build_switch_expr(p),
-                _ => unreachable!(),
+                Rule::call_expr => return build_call_expr(p),
+                r => unreachable!("Encountered unknown op {:?}", r),
             };
             let term = build_expr_primary(inner.next().unwrap())?;
             Ok(Expr::Apply(op, vec![term]))
@@ -284,6 +287,14 @@ fn build_expr_primary(pair: Pair) -> Result<Expr> {
     }
 }
 
+fn get_method(name: &str) -> Arc<dyn Op + Send + Sync> {
+    match name {
+        n if n == OpIsNull.name() => Arc::new(OpIsNull),
+        n if n == OpNotNull.name() => Arc::new(OpNotNull),
+        method_name => Arc::new(UnresolvedOp(method_name.to_string()))
+    }
+}
+
 fn build_expr_infix<'a>(
     lhs: Result<Expr<'a>>,
     op: Pair,
diff --git a/src/grammar.pest b/src/grammar.pest
index 9d833e56..54503786 100644
--- a/src/grammar.pest
+++ b/src/grammar.pest
@@ -103,18 +103,16 @@ op_ge = { ">=" }
 op_le = { "<=" }
 op_pow = { "^" }
 
-unary = { cond_expr | switch_expr | if_expr | (unary_op ~ unary) | term }
+unary = { cond_expr | switch_expr | if_expr | call_expr | (unary_op ~ unary) | term }
 unary_op = _{ minus | negate }
 minus = { "-" }
 negate = { "!" }
 
+call_expr = { ident ~ "(" ~ (expr ~ ",")* ~ expr? ~ ")" }
 term = { (grouping | literal | ident | param | list | dict) ~ (call | accessor | index_accessor)* }
-call = {"." ~ ident ~ "(" ~ argument* ~ ")"}
+call = {"." ~ ident ~ "(" ~ (expr ~ ",")* ~ expr? ~ ")"}
 accessor = {"." ~ ident}
 index_accessor = {"[" ~ int ~ "]"}
-argument = _{(kw_arg | pos_arg)}
-kw_arg = {ident ~ "=" ~ expr}
-pos_arg = { expr }
 grouping = { "(" ~ expr ~ ")" }
 
 if_expr = { if_clause ~ ("else" ~ if_clause)* ~ else_clause? }