Reference

HAL API
hal_api()	HAL API
Query building
hal_facet()	Facet Search
hal_filter()	Filter Results
hal_group()	Group Results
hal_query() `%OR%` `%AND%` `%NOT%` `%BY%` `%IN%` `%TO%`	Build Query
hal_select()	Select Fields
hal_sort() hal_sort()	Sort Results
Search and Download
hal_download()	Download Documents
hal_count() hal_search()	Search