field access operator

cozo-core/src/cozoscript.pest

@@ -100,12 +100,13 @@ named_apply_pair = {underscore_ident ~ (":" ~ expr)?}
 grouped = _{"(" ~ rule_body ~ ")"}
 
 expr = {unary_op* ~ term ~ (operation ~ unary_op* ~ term)*}
-operation = _{ (op_and | op_or | op_pow | op_concat | op_add | op_sub | op_mul | op_div | op_mod |
+operation = _{ (op_and | op_or | op_pow | op_concat | op_add | op_field_access | op_sub | op_mul | op_div | op_mod |
                 op_ge | op_le | op_gt | op_lt | op_eq | op_ne | op_coalesce )}
 op_or = { "||" }
 op_and = { "&&" }
 op_concat = { "++" }
 op_add = { "+" }
+op_field_access = { "->" }
 op_sub = { "-" }
 op_mul = { "*" }
 op_div = { "/" }

cozo-core/src/parse/expr.rs

@@ -18,7 +18,8 @@ use thiserror::Error;
 use crate::data::expr::{get_op, Bytecode, Expr, NoImplementationError};
 use crate::data::functions::{
     OP_ADD, OP_AND, OP_COALESCE, OP_CONCAT, OP_DIV, OP_EQ, OP_GE, OP_GT, OP_JSON_OBJECT, OP_LE,
-    OP_LIST, OP_LT, OP_MINUS, OP_MOD, OP_MUL, OP_NEGATE, OP_NEQ, OP_OR, OP_POW, OP_SUB,
+    OP_LIST, OP_LT, OP_MAYBE_GET, OP_MINUS, OP_MOD, OP_MUL, OP_NEGATE, OP_NEQ, OP_OR, OP_POW,
+    OP_SUB,
 };
 use crate::data::symb::Symbol;
 use crate::data::value::DataValue;
@@ -45,6 +46,7 @@ lazy_static! {
             .op(Op::infix(Rule::op_coalesce, Left))
             .op(Op::prefix(Rule::minus))
             .op(Op::prefix(Rule::negate))
+            .op(Op::infix(Rule::op_field_access, Left))
     };
 }
 
@@ -160,6 +162,7 @@ fn build_expr_infix(lhs: Result<Expr>, op: Pair<'_>, rhs: Result<Expr>) -> Resul
         Rule::op_or => &OP_OR,
         Rule::op_and => &OP_AND,
         Rule::op_coalesce => &OP_COALESCE,
+        Rule::op_field_access => &OP_MAYBE_GET,
         _ => unreachable!(),
     };
     let start = args[0].span().0;