implement // operator

2 files changed, 16 insertions, 0 deletions

diff --git a/src/jq/codegen.zig b/src/jq/codegen.zig
index e377a5c..21c5832 100644
--- a/src/jq/codegen.zig
+++ b/src/jq/codegen.zig
@@ -28,6 +28,7 @@ pub const Opcode = enum {
     gt,
     le,
     ge,
+    alt,
     @"const",
     const_true,
     const_false,
@@ -58,6 +59,7 @@ pub const Instr = union(Opcode) {
     gt,
     le,
     ge,
+    alt,
     @"const": ConstIndex,
     const_true,
     const_false,
@@ -108,6 +110,7 @@ const Codegen = struct {
                     .gt => .gt,
                     .le => .le,
                     .ge => .ge,
+                    .alt => .alt,
                     else => return error.Unimplemented,
                 };
                 try self.emit(op_instr);
diff --git a/src/jq/execute.zig b/src/jq/execute.zig
index f2bfe8c..0565004 100644
--- a/src/jq/execute.zig
+++ b/src/jq/execute.zig
@@ -328,6 +328,19 @@ pub const Runtime = struct {
                     const result = try jv.ops.compare(lhs, rhs, .ge);
                     try self.values.push(.{ .bool = result });
                 },
+                .alt => {
+                    std.debug.assert(self.values.ensureSize(3));
+
+                    _ = self.values.pop();
+                    const lhs = self.values.pop();
+                    const rhs = self.values.pop();
+                    const is_falsy = switch (lhs) {
+                        .null => true,
+                        .bool => |b| !b,
+                        else => false,
+                    };
+                    try self.values.push(if (is_falsy) rhs else lhs);
+                },
                 .@"const" => |idx| {
                     std.debug.assert(self.values.ensureSize(1));