1:- module(xsd_helper, [ 2 /* ### node type translation ### */ 3 node_type/3, 4 /* ### node relations ### */ 5 /* --- parent-child --- */ 6 parent/2, 7 split_id/3, 8 child/3, 9 get_children/3, 10 get_n_children/4, 11 get_nth_child/4, 12 count_children/3, 13 /* --- sibling --- */ 14 sibling/3, 15 next_sibling/3, 16 last_sibling/3, 17 count_remaining_siblings/3, 18 get_n_siblings/4, 19 get_nth_sibling/4, 20 /* --- ancestor/descendant --- */ 21 descendant/3, 22 descendant_or_self/3, 23 /* ### namespace handling ### */ 24 resolve_namespace/4, 25 namespace/3 26]). 27 28:- use_module(library(xsd/flatten)). 29 30/* 31 HELPER 32 Various predicates for data traversal, receiving children and siblings and namespace handling using nodes created by `flatten_xml/2` inside the Module `xml_flatten` 33 34 parent(ID, Parent_ID) 35 child(File,ID,Child_ID) 36 sibling(File,ID,Sibling_ID) 37 38 ?- child("test/schema.xsd", [0], [0,0]). 39 true. 40 ?- child("test/schema.xsd", [0,0], _). 41 false. 42*/ 43 44 45/* ### node type translation ### */ 46 47node_type(File, ID, node) :- 48 node(File, ID, _NS, _Name). 49node_type(File, ID, text_node) :- 50 text_node(File, ID, _). 51 52 53/* ### node relations ### */ 54 55/* --- parent-child --- */ 56 57parent(ID, Parent_ID) :- 58 split_id(ID, _, Parent_ID). 59split_id(ID, Pos, Parent_ID) :- 60 ID = [Pos|Parent_ID]. 61 62child(File, ID, Child_ID) :- 63 Child_ID = [_|ID], 64 node_type(File, Child_ID, _). 65 66get_children(File, ID, Children_IDs) :- 67 findall(Child_ID, child(File, ID, Child_ID), Children_IDs). 68 69get_n_children(File, ID, N, Children_IDs) :- 70 get_children(File, ID, All_Children_IDs), 71 length(Children_IDs, N), 72 append(Children_IDs, _, All_Children_IDs).
77get_nth_child(File, ID, Nth, Child_ID) :- 78 Nth0 is Nth - 1, 79 Nth0 >= 0, 80 split_id(Child_ID, Nth0, ID), 81 node_type(File, Child_ID, _). 82 83count_children(File, ID, N_Children) :- 84 get_children(File, ID, Children), 85 length(Children, N_Children). 86 87/* --- sibling --- */ 88 89sibling(File, ID, Sibling_ID) :- 90 parent(ID, Parent_ID), 91 child(File, Parent_ID, Sibling_ID), 92 ID \= Sibling_ID. 93 94next_sibling(File, ID, Next_Sibling_ID) :- 95 split_id(ID, Pos, Parent_ID), 96 Next is Pos + 1, 97 split_id(Next_Sibling_ID, Next, Parent_ID), 98 child(File, Parent_ID, Next_Sibling_ID). 99 100last_sibling(File, ID, Last_Sibling_ID) :- 101 parent(ID, Parent_ID), 102 child(File, Parent_ID, Last_Sibling_ID), 103 \+next_sibling(File, Last_Sibling_ID, _).
108count_remaining_siblings(File, ID, Remaining) :- 109 split_id(ID, Pos0, Parent_ID), 110 last_sibling(File, ID, Last_ID), 111 split_id(Last_ID, Pos1, Parent_ID), 112 Remaining is Pos1 - Pos0 + 1. 113 114get_n_siblings(_File, _ID, 0, []). 115get_n_siblings(_File, ID, 1, [ID]). 116get_n_siblings(File, ID, N, [ID|Sibling_IDs]) :- 117 count_remaining_siblings(File, ID, Remaining), 118 between(2, Remaining, N), 119 split_id(ID, Pos, Parent_ID), 120 Pos0 is Pos + 1, 121 N0 is N - 1, 122 split_id(ID0, Pos0, Parent_ID), 123 node_type(File, ID0, _), 124 get_n_siblings(File, ID0, N0, Sibling_IDs).
132get_nth_sibling(D_File, ID, Nth, Nth_ID) :- 133 split_id(ID, Pos, Parent_ID), 134 N is Pos + Nth - 1, 135 split_id(Nth_ID, N, Parent_ID), 136 node_type(D_File, Nth_ID, _). 137 138/* --- ancestor/descendant --- */ 139 140descendant(File, ID, Desc_ID) :- 141 child(File, ID, Desc_ID). 142descendant(File, ID, Desc_ID) :- 143 child(File, Inter_ID, Desc_ID), 144 descendant(File, ID, Inter_ID). 145 146descendant_or_self(File, ID, ID) :- 147 node(File, ID, _NS, _Name). 148descendant_or_self(File, ID, Desc_ID) :- 149 descendant(File, ID, Desc_ID). 150 151 152/* ### namespace handling ### */
159resolve_namespace(File, ID, Prefix, URI) :- 160 node(File, ID, ns(Prefix, URI), _), 161 !. 162resolve_namespace(File, ID, Prefix, URI) :- 163 node_attribute(File, ID, xmlns:Prefix, URI), 164 !. 165resolve_namespace(File, ID, '', URI) :- 166 node_attribute(File, ID, xmlns, URI), 167 !. 168resolve_namespace(File, ID, Prefix, URI) :- 169 parent(ID, Parent_ID), 170 resolve_namespace(File, Parent_ID, Prefix, URI).
Examples:
namespace(xs:element,xs,element).
namespace(element,'',element).
/
182namespace(Name,Namespace,Name_Without_NS) :- 183 Name = Namespace:Name_Without_NS, 184 !. 185% Namespace in 'single:quotes' 186namespace(Name_String,Namespace,Name_Without_NS) :- 187 atom(Name_String), 188 atomic_list_concat([Namespace,Name_Without_NS], ':', Name_String), 189 !. 190% no namespace present 191namespace(Name,'',Name)