feat(tvix/eval): implement builtins.all

Change-Id: I19ec2b2194681efd73041f4aa1e5f2c893e839c2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6844
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

tvix/eval/src/builtins/mod.rs

@@ -61,6 +61,20 @@ fn pure_builtins() -> Vec<Builtin> {
         Builtin::new("abort", &[true], |args, _| {
             Err(ErrorKind::Abort(args[0].to_str()?.to_string()))
         }),
+        Builtin::new("all", &[true, true], |args, vm| {
+            for value in args[1].to_list()?.into_iter() {
+                let pred_result = {
+                    vm.push(value);
+                    vm.call_value(&args[0])
+                }?;
+
+                if !pred_result.force(vm)?.as_bool()? {
+                    return Ok(Value::Bool(false));
+                }
+            }
+
+            Ok(Value::Bool(true))
+        }),
         Builtin::new("attrNames", &[true], |args, _| {
             let xs = args[0].to_attrs()?;
             let mut output = Vec::with_capacity(xs.len());

tvix/eval/src/tests/tvix_tests/eval-okay-builtins-all.exp

@@ -0,0 +1 @@
+[ true true false false false false true true false ]

tvix/eval/src/tests/tvix_tests/eval-okay-builtins-all.nix

@@ -0,0 +1,15 @@
+[
+  (builtins.all (x: x) [ ])
+  (builtins.all (x: x) [ true true true ])
+  (builtins.all (x: x) [ false false false ])
+  (builtins.all (x: x) [ true true false ])
+  (builtins.all (x: x) [ false true true ])
+
+  # evaluation should short-circuit
+  (builtins.all (x: x) [ true false (builtins.abort "should be unreachable") ])
+
+  # arbitrary functions supported
+  (builtins.all (x: x * 2 == 42) [ ])
+  (builtins.all (x: x * 2 == 42) [ 21 21 21 ])
+  (builtins.all (x: x * 2 == 42) [ 1 2 3 ])
+]