Search before you write

Flow ships around seventy standard library modules and several hundred worked examples. The project's own record is that its most useful changes replaced private helpers with shared ones. Look first.

The three searches

# 1. Does a function like this exist?
grep -rn --include='*.flow' "function name_you_want" lib/stdlib/ examples/

# 2. What does this module offer?
grep -n "^export function\|^function\|^struct\|^const" lib/stdlib/math.flow

# 3. Who already does this thing?
grep -rln --include='*.flow' "evolves as" examples/

Or use the packaged tool, which does all three:

flow-find sample_rate
flow-find "evolves as"

The map

ls lib/stdlib/ for the current list. This table goes stale; the directory does not.

Import syntax

import "stdlib/math.flow"
import "stdlib/audio/oscillators.flow"
import "stdlib/dynamics/state_space.flow"

Quoted paths rooted at stdlib/, which resolves to lib/stdlib/ in the checkout. Functions a module means to expose are marked export function.

Examples are the second library

ls examples/

basics, evolution, dynamics, effects, games, graphics, audio, dsp, ml, ai, neuro, morphogenesis, evoleco, planet, procgen, circuits, rf, physics, numerical, linalg, stats, crypto, net, concurrency, systems, interop, wasm, gpu, threed, ui, data, compilers, verify, book, bench, demos.

Most shipped examples end with self-checks that return a distinct code per failure. Copy that habit; it turns an example into a test.

When nothing exists

Write the smallest helper that solves the case at hand, put it next to the code that uses it, and say in your report that you searched and found nothing. If the same helper shows up a second time, that is the moment to propose moving it into lib/stdlib/.

Do not add a language construct to remove one repeated line.