cue: fix cycle issue
If evaluated in a certain order, cycles within
expressions were cached too early.
Fixes cuelang/cue#19.
Change-Id: I795f18d6767b3d474712fd550faa3a4d4994605a
diff --git a/cue/resolve_test.go b/cue/resolve_test.go
index 18b5c6a..9700eba 100644
--- a/cue/resolve_test.go
+++ b/cue/resolve_test.go
@@ -443,6 +443,22 @@
`,
out: `<0>{a: 100, b: 200, c: _|_(cycle detected), s1: <1>{a: 1, b: 2, c: 3}, s2: <2>{a: 1, b: 2, c: 3}, s3: <3>{a: 1, b: 2, c: 3}}`,
}, {
+ desc: "resolved self-reference cycles: Issue 19",
+ in: `
+ // CUE knows how to resolve the following:
+ x: y + 100
+ y: x - 100
+ x: 200
+
+ z1: z2 + 1
+ z2: z3 + 2
+ z3: z1 - 3
+ z3: 8
+
+ // TODO: extensive tests with disjunctions.
+ `,
+ out: `<0>{x: 200, y: 100, z1: 11, z2: 10, z3: 8}`,
+ }, {
desc: "delayed constraint failure",
in: `
a: b - 100
diff --git a/cue/value.go b/cue/value.go
index 5c34b96..a986b10 100644
--- a/cue/value.go
+++ b/cue/value.go
@@ -628,7 +628,7 @@
v = x.applyTemplate(ctx, i, v)
- if ctx.evalDepth > 0 && ctx.cycleErr {
+ if (ctx.evalDepth > 0 && ctx.cycleErr) || cycleError(v) != nil {
// Don't cache while we're in a evaluation cycle as it will cache
// partial results. Each field involved in the cycle will have to
// reevaluated the values from scratch. As the result will be
@@ -636,7 +636,8 @@
x.arcs[i].cache = nil
return v
}
- // If there as a cycle error, we have by now evaluated full cycle and
+
+ // If there as a cycle error, we have by now evaluated a full cycle and
// it is safe to cache the result.
ctx.cycleErr = false
