| cue eval -i -c cycle.cue |
| cmp stdout expect-stdout-cue |
| |
| -- frontmatter.toml -- |
| title = "Reference Cycles" |
| description = "" |
| |
| -- text.md -- |
| CUE can handle many types of cycles just fine. |
| Because all values are final, a field with a concrete value of, say `200`, |
| can only be valid if it is that value. |
| So if it is unified with another expression, we can delay the evaluation of |
| this until later. |
| |
| By postponing that evaluation, we can often break cycles. |
| This is very useful for template writers that may not know what fields |
| a user will want to fill out. |
| |
| -- cycle.cue -- |
| // CUE knows how to resolve the following: |
| x: 200 |
| x: y + 100 |
| y: x - 100 |
| |
| // If a cycle is not broken, CUE will just report it. |
| a: b + 100 |
| b: a - 100 |
| |
| -- expect-stdout-cue -- |
| x: 200 |
| y: 100 |
| a: _|_ // cycle detected |
| b: _|_ // cycle detected |
