Env

Env module: environment variable access for application configuration.

Env.get/2 reads an env var, returning a default String if not set. Env.require/1 reads a required env var, panicking if absent. Env.get_int/2 and Env.get_bool/2 parse the raw string into typed values.

These are the primitives used in config/runtime.march files to build environment-specific configuration at application startup.

Usage: Env.get("PORT", "4000") -- "4000" (or env value) Env.require("SECRET_KEY_BASE") -- panics if not set Env.get_int("PORT", 4000) -- 4000 (parsed as Int) Env.get_bool("DEBUG", false) -- false (or true if "true"/"1"/"yes")

Functions

fngetget(name, default)#

Read an environment variable, returning default if not set.

Examples

    march> Env.get("MARCH_DOCTEST_NEVER_SET", "fallback")
    "fallback"

fnget_boolget_bool(name, default)#

Read an environment variable and parse as Bool. Truthy values: "true", "1", "yes" (case-sensitive). All other values — including absent — fall back to default.

Examples

    march> Env.get_bool("MARCH_DOCTEST_NEVER_SET", false)
    false
    march> Env.get_bool("MARCH_DOCTEST_NEVER_SET", true)
    true

fnget_intget_int(name, default)#

Read an environment variable and parse it as Int. Returns default if the variable is not set OR if it is set but not a valid integer (so callers can keep their typed default safely).

Examples

    march> Env.get_int("MARCH_DOCTEST_NEVER_SET", 8080)
    8080

fnis_setis_set(name)#

Return true if the variable is set to any value (including the empty string), false otherwise.

Examples

    march> Env.is_set("MARCH_DOCTEST_NEVER_SET")
    false

fnrequirerequire(name)#

Read a required environment variable. Panics if not set, with the variable name in the message so the failure is self-diagnosing.

Examples

    march> Env.require("MARCH_DOCTEST_NEVER_SET")
    ** panic: Env: required variable not set: MARCH_DOCTEST_NEVER_SET

fnrequire_intrequire_int(name)#

Read a required environment variable and parse it as Int. Panics if the variable is not set or its value does not parse as an integer (the message includes both the name and the offending value when the latter applies).

Examples

    march> Env.require_int("MARCH_DOCTEST_NEVER_SET")
    ** panic: Env: required variable not set: MARCH_DOCTEST_NEVER_SET