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95 lines
2.9 KiB
OpenEdge ABL
95 lines
2.9 KiB
OpenEdge ABL
[ReferenceInstruction::] The Reference Construct.
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Defining the Reference construct.
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@h Definition.
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For what this does and why it is used, see //inter: Textual Inter//.
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=
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void ReferenceInstruction::define_construct(void) {
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inter_construct *IC = InterInstruction::create_construct(REFERENCE_IST, I"reference");
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InterInstruction::specify_syntax(IC, I"reference");
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InterInstruction::data_extent_always(IC, 0);
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InterInstruction::allow_in_depth_range(IC, 1, INFINITELY_DEEP);
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InterInstruction::permit(IC, INSIDE_CODE_PACKAGE_ICUP);
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InterInstruction::permit(IC, CAN_HAVE_CHILDREN_ICUP);
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METHOD_ADD(IC, CONSTRUCT_READ_MTID, ReferenceInstruction::read);
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METHOD_ADD(IC, CONSTRUCT_WRITE_MTID, ReferenceInstruction::write);
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METHOD_ADD(IC, CONSTRUCT_VERIFY_CHILDREN_MTID, ReferenceInstruction::verify_children);
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}
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@h Instructions.
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In bytecode, the frame of a |reference| instruction is laid out with just the two
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compulsory words -- see //Inter Nodes//.
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=
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inter_error_message *ReferenceInstruction::new(inter_bookmark *IBM, int level,
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inter_error_location *eloc) {
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inter_tree_node *P = Inode::new_with_0_data_fields(IBM, REFERENCE_IST,
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eloc, (inter_ti) level);
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inter_error_message *E = VerifyingInter::instruction(InterBookmark::package(IBM), P);
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if (E) return E;
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NodePlacement::move_to_moving_bookmark(P, IBM);
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return NULL;
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}
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@ Verification consists only of sanity checks.
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=
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void ReferenceInstruction::verify_children(inter_construct *IC, inter_tree_node *P,
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inter_error_message **E) {
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LOOP_THROUGH_INTER_CHILDREN(C, P) {
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if ((C->W.instruction[0] != INV_IST) &&
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(C->W.instruction[0] != REF_IST) &&
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(C->W.instruction[0] != SPLAT_IST) &&
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(C->W.instruction[0] != VAL_IST) &&
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(C->W.instruction[0] != LABEL_IST)) {
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*E = Inode::error(C, I"instruction cannot be referenced", NULL);
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return;
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}
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}
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}
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@h Creating from textual Inter syntax.
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=
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void ReferenceInstruction::read(inter_construct *IC, inter_bookmark *IBM,
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inter_line_parse *ilp, inter_error_location *eloc, inter_error_message **E) {
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*E = ReferenceInstruction::new(IBM, ilp->indent_level, eloc);
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}
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@h Writing to textual Inter syntax.
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=
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void ReferenceInstruction::write(inter_construct *IC, OUTPUT_STREAM, inter_tree_node *P) {
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WRITE("reference");
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}
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@h Detection.
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This tests whether a node |P| represents a reference to a primitive of a given
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BIP. So, for example, it can look for the configuration
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= (text as Inter)
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reference
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inv !propertyvalue
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...
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=
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by being called with |seek_bip| equal to |PROPERTYVALUE_BIP|.
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=
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int ReferenceInstruction::node_is_ref_to(inter_tree *I, inter_tree_node *P,
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inter_ti seek_bip) {
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int reffed = FALSE;
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while (Inode::is(P, REFERENCE_IST)) {
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P = InterTree::first_child(P);
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reffed = TRUE;
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}
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if (Inode::is(P, INV_IST)) {
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if (InvInstruction::method(P) == PRIMITIVE_INVMETH) {
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inter_symbol *prim = InvInstruction::primitive(P);
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inter_ti bip = Primitives::to_BIP(I, prim);
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if ((bip == seek_bip) && (reffed)) return TRUE;
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}
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}
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return FALSE;
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}
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