Reference

These pages describe what the binary implements. Where a model or card describes language the binary does not run yet, its status line says so.

Page	Covers
Expressions	The grammar the parser accepts, and how expressions are checked
Command line	hql's commands, options, exit codes and configuration
Reporting	Warnings, errors and failures, and the strict and collect modes
Queries	How a query is sourced and traversed
Program values	What a program returns, and what the host does with it
Design status	Every design card, and the decisions still open

Commands at a glance

Command	What it does
hql eval <program>	check and evaluate an argument
hql check <file>	print the type without evaluating
hql run <file>	check and evaluate a file
hql repl	read, evaluate and print, keeping bindings
hql render <file>	run the HQL blocks in a document, transcluding the answers
hql builtins	list the steps
hql config	the reporting mode in force, and where it came from

- reads standard input wherever a file is taken. Success is exit 0, a language or I/O failure 1, a usage error 2.

The standard library

The types HQL knows are declared in HQL itself, under std/: core, collections, doc, graph, knowledge and retrieval. The checker reads those declarations rather than assuming them.