Overview of Failure Statements

Quxlang provides explicit assertions, runtime termination, compile-time rejection, and unimplemented-path markers.

For recoverable failures, use Exception Handling. CATCH does not intercept failed assertions or PANIC.

Assertions

ASSERT(condition);
ASSERT(condition, "condition was false");

When ASSERT_ENABLED is enabled, an assertion failure terminates the current execution mode. In a STATIC_TEST it is a static execution failure; in runtime code it follows the runtime assertion path.

Panic

PANIC "unrecoverable state";

PANIC is a terminal statement. Its message is optional.

Compilation errors

COMPILATION_ERROR "this source configuration is unsupported";
COMPILATION_ERROR ON_LOWER "this path cannot be lowered";

COMPILATION_ERROR rejects a selected source path. ON_LOWER delays the error until the statement is lowering-reachable, which lets an explicit runtime-mode or target selection keep an unsupported implementation out of unrelated paths.

Unimplemented paths

UNIMPLEMENTED;

unimplemented_compiles: false rejects this statement during code generation. With the default true, UNIMPLEMENTED_PANICS selects a panic when enabled or a compilation error for a lowering-reachable path when disabled. Release builds disable this policy by default.

Expected-failure test declarations are documented on Tests, and the target setting is listed under The qxcbuild.yml File.

Assertions in tests

TEST_ASSERT(condition) defines an assertion that always runs. TEST_EXPECT(condition) throws TEST_FAILED on failure. Both forms accept an optional diagnostic string. Ordinary ASSERT can omit its condition entirely under the output's compilation policies.

Reference

See the Failure Statements Reference for the complete language rules, constraints, and technical edge cases.