Dependencies

Resolve dependencies before target bodies

Put prerequisites in depends [name, ...], before the body or a debug clause. Dependencies are target names, not shell commands or file paths.

import project
target assets { print "prepare assets" }
target validate depends [assets] { assert 2 + 2 == 4 }
target preview depends [assets] { print "preview ready" }
target all depends [validate, preview] { print "all ready" }

The shared assets target runs once when resolving all. A failed dependency prevents dependent bodies from running. A missing target or cyclic dependency is an error; do not use cycles as a mechanism for repeated execution.

Separate definition from effects

Create values and phrases needed by multiple targets outside their bodies. Keep side effects inside the target that owns them. Declaring a target is safe during project discovery precisely because its body remains deferred. A target that writes a file should make that effect explicit in its own source and handle failures before returning success.

Distinguish targets from file caches

Target execution is dependency-driven, not an automatic file timestamp cache. Do not assume that an unchanged input file causes a target to be skipped across separate runtime invocations.