Language reference
env (environment declaration)
Syntax
env;
env from "<file>";
env using "<profile>";
env from "<file>" using "<profile>";
env from "relix-env.json" using "development";Description
env names the file and the profile that a script's ${VAR} placeholders are meant to be resolved from, so the script says where its configuration comes from instead of leaving it to whoever runs it. It carries no values itself: a token, a password or a URL stays out of the script, and the script holds ${NAME} where it goes (see connection and http source).
The statement is optional. When present it comes first, after a namespace if there is one, and before every other statement; there is at most one.
Technical Description
from takes a string giving the file's path, and using a string giving a profile within it. Each is optional, and both may be left out (env;). Both must be written as double-quoted strings.
The engine records the statement and does nothing else with it. It is parsed, printed back with the rest of the script, and ignored by analysis, planning and execution: no file is read, no profile is selected, and a script that names a file that does not exist is not an error. Where a ${NAME} placeholder gets its value is decided by the program that runs the script, not by the engine. A program embedding Relix gives the session a resolver of its own; the relix command resolves a placeholder from -D, a profile (-P) or the environment, and ignores the statement. The interactive relix-repl ignores it too: it takes the environment from its own --env <name> option or the :env <name> command, reading relix-env.json files from the working directory up to the home directory.
A session built with a sealed sandbox refuses the statement, as it refuses any statement that reaches outside the session.
Examples
A script that names its environment file and profile, and otherwise runs as usual. The statement has to be the first in a script, so these are shown as they would be saved:
env from "relix-env.json" using "development";
Tiers := [
| tier | rate |
|--------|------|
| bronze | 5 |
| silver | 8 |
];
query { Tiers };The shortest form, which names neither:
env;
Tiers := [
| tier | rate |
|--------|------|
| bronze | 5 |
];
query { Tiers };Limitations
The engine reads no environment file, so a from path does not by itself make a placeholder resolve, and nothing in this statement can be used to check that the file exists or that the profile is defined in it.
Alternatives
Give the session a placeholder resolver, which is how an embedding program supplies values (see the programming guide's chapter on secrets), or bind a name for one run with the relix command's -D NAME=VALUE, or put the values in a profile and choose it with -P.
See Also
Notes
${NAME} is resolved when a query runs rather than when the script is loaded, so the value never appears in definitions() or in an error message.