[david-Darkcollective]

S10 (#14), part of #17: -a/--arg NAME=VALUE binds the query parameter $NAME outside the script text.

relix -a id=42 order.relix
xargs -I{} relix -a id={} order.relix

What it does

• -a is repeatable and global, like -D, so it can come before or after the command and the script. Values go to the engine through Relix.Builder.parameters and are never pasted into the text.
• A value is text. The engine reads it as the type the parameter was analysed to (Bind a parameter from text: convert a String to the parameter's analysed type relix-core#101, in rc8), so -a id=42 binds a number when $id is compared with a NUMBER column. Text that doesn't read as that type is an analysis error (exit 3) naming the parameter, the type and the text.
• An unbound parameter is an analysis error (exit 3) that names it. The engine's message suggests a Java call, so the new EngineMessages rewrites that one message for the command line:
  relix: order.relix: parameter $id is not bound; give it a value with -a id=VALUE
  Every other engine message passes through unchanged.
• fmt, bundle and optimize print $name, never the value.
• docs/design.md §4 lists -a.

Tests

QueryParametersTest covers the issue's acceptance points through Main:

• binding, with --arg, after the script, and several -a at once;
• a value holding a quote, Paris' ∨ '1' = '1, matches nothing and can't change the query;
• a numeric parameter bound from text, and text of the wrong type;
• the exact unbound-parameter error and its exit status;
• fmt, bundle and optimize printing $city and not the value.

CI: the two FmtTest failures on league.relix aren't caused by this branch; they fail on develop too. They clear once DarkCollective/relix-core#106 reaches the snapshot and #38 merges. Everything else passes.