Add CodeableReference keyword

antlr/src/main/antlr/FSH.g4

@@ -114,10 +114,11 @@ quantity:           NUMBER (UNIT | CODE) STRING?;
 ratio:              ratioPart COLON ratioPart;
 reference:          REFERENCE STRING?;
 referenceType:      REFERENCE;
+codeableReferenceType: CODEABLE_REFERENCE;
 canonical:          CANONICAL;
 ratioPart:          NUMBER | quantity;
 bool:               KW_TRUE | KW_FALSE;
-targetType:         name | referenceType | canonical;
+targetType:         name | referenceType | canonical | codeableReferenceType;
 mostAlphaKeywords:  KW_MS
                     | KW_SU
                     | KW_TU

antlr/src/main/antlr/FSHLexer.g4

@@ -92,6 +92,9 @@ CARD:               ([0-9]+)? '..' ([0-9]+ | '*')?;
               //  Reference       (        ITEM         |         ITEM         )
 REFERENCE:       'Reference' WS* '(' WS* SEQUENCE WS* (WS 'or' WS+ SEQUENCE WS*)* ')';
 
+                 // CodeableReference       (         ITEM           or          ITEM         )
+CODEABLE_REFERENCE: 'CodeableReference' WS* '(' WS* SEQUENCE WS* (WS 'or' WS+ SEQUENCE WS*)* ')';
+
                  // Canonical       (              URL|VERSION               or              URL|VERSION             )
 CANONICAL     :    'Canonical' WS* '(' WS* SEQUENCE ('|' SEQUENCE)? WS* (WS 'or' WS+ SEQUENCE ('|' SEQUENCE)? WS*)* ')';
 

src/errors/InvalidTypeError.ts

@@ -1,6 +1,5 @@
 import { Annotated } from './Annotated';
 import { ElementDefinitionType } from '../fhirtypes';
-import { isReferenceType } from '../fhirtypes/common';
 
 export class InvalidTypeError extends Error implements Annotated {
   specReferences = [
@@ -29,8 +28,10 @@ function allowedTypesToString(types: ElementDefinitionType[]): string {
   }
   const strings: string[] = [];
   types.forEach(t => {
-    if (isReferenceType(t.code)) {
+    if (t.code === 'Reference') {
       strings.push(`Reference(${(t.targetProfile ?? []).join(' | ')})`);
+    } else if (t.code === 'CodeableReference') {
+      strings.push(`CodeableReference(${(t.targetProfile ?? []).join(' | ')})`);
     } else if (t.code === 'canonical') {
       strings.push(`Canonical(${(t.targetProfile ?? []).join(' | ')})`);
     } else if (t.profile?.length > 0) {

src/fhirtypes/ElementDefinition.ts

@@ -22,7 +22,7 @@ import {
   Invariant,
   SourceInfo
 } from '../fshtypes';
-import { AddElementRule, AssignmentValueType, OnlyRule } from '../fshtypes/rules';
+import { AddElementRule, AssignmentValueType, OnlyRule, OnlyRuleType } from '../fshtypes/rules';
 import {
   AssignmentToCodeableReferenceError,
   BindingStrengthError,
@@ -590,21 +590,28 @@ export class ElementDefinition {
    */
   private initializeElementType(rule: AddElementRule, fisher: Fishable): ElementDefinitionType[] {
     if (rule.types.length > 1 && !rule.path.endsWith('[x]')) {
-      // Reference/Canonical data type with multiple targets is not considered a choice data type.
-      if (!rule.types.every(t => t.isReference) && !rule.types.every(t => t.isCanonical)) {
+      // Reference/Canonical/CodeableReference data type with multiple targets is not considered a choice data type.
+      if (
+        !rule.types.every(t => t.isReference) &&
+        !rule.types.every(t => t.isCanonical) &&
+        !rule.types.every(t => t.isCodeableReference)
+      ) {
         throw new InvalidChoiceTypeRulePathError(rule);
       }
     }
 
     let refTypeCnt = 0;
     let canTypeCnt = 0;
+    let codeableRefTypeCnt = 0;
 
     const initialTypes: ElementDefinitionType[] = [];
     rule.types.forEach(t => {
       if (t.isReference) {
         refTypeCnt++;
       } else if (t.isCanonical) {
         canTypeCnt++;
+      } else if (t.isCodeableReference) {
+        codeableRefTypeCnt++;
       } else {
         const metadata = fisher.fishForMetadata(t.type);
         initialTypes.push(new ElementDefinitionType(metadata.sdType));
@@ -622,10 +629,16 @@ export class ElementDefinition {
       // will contain the URLs for each canonical.
       finalTypes.push(new ElementDefinitionType('canonical'));
     }
+    if (codeableRefTypeCnt > 0) {
+      // We only need to capture a single CodeableReference type. The targetProfiles attribute
+      // will contain the URLs for each CodeableReference reference.
+      finalTypes.push(new ElementDefinitionType('CodeableReference'));
+    }
 
     const refCheckCnt = refTypeCnt > 0 ? refTypeCnt - 1 : 0;
     const canCheckCnt = canTypeCnt > 0 ? canTypeCnt - 1 : 0;
-    if (rule.types.length !== finalTypes.length + refCheckCnt + canCheckCnt) {
+    const codableRefCheckCnt = codeableRefTypeCnt > 0 ? codeableRefTypeCnt - 1 : 0;
+    if (rule.types.length !== finalTypes.length + refCheckCnt + canCheckCnt + codableRefCheckCnt) {
       logger.warn(
         `${rule.path} includes duplicate types. Duplicates have been ignored.`,
         rule.sourceInfo
@@ -947,6 +960,19 @@ export class ElementDefinition {
     const targetType = this.getTargetType(target, fisher);
     const targetTypes: ElementDefinitionType[] = targetType ? [targetType] : this.type;
 
+    // If the target type is a CodeableReference but the rule types were set via the Reference() keyword,
+    // log a warning to use CodeableReference keyword
+    if (
+      targetTypes.some(t => t.code === 'CodeableReference') &&
+      !targetTypes.some(t => t.code === 'Reference') &&
+      rule.types.some(t => t.isReference)
+    ) {
+      logger.warn(
+        'The CodeableReference() keyword should be used to constrain references of a CodeableReference',
+        rule.sourceInfo
+      );
+    }
+
     // Setup a map to store how each existing element type maps to the input types
     const typeMatches: Map<string, ElementTypeMatchInfo[]> = new Map();
     targetTypes.forEach(t => typeMatches.set(t.code, []));
@@ -1135,7 +1161,7 @@ export class ElementDefinition {
   /**
    * Given an input type (the constraint) and a set of target types (the things to potentially
    * constrain), find the match and return information about it.
-   * @param {{ type: string; isReference?: boolean; isCanonical?: boolean }} type - the constrained
+   * @param {OnlyRuleType} type - the constrained
    *   types, identified by id/type/url string and an optional reference/canonical flags (defaults false)
    * @param {ElementDefinitionType[]} targetTypes - the element types that the constrained type
    *   can be potentially applied to
@@ -1147,7 +1173,7 @@ export class ElementDefinition {
    * @throws {InvalidTypeError} when the type doesn't match any of the targetTypes
    */
   private findTypeMatch(
-    type: { type: string; isReference?: boolean; isCanonical?: boolean },
+    type: OnlyRuleType,
     targetTypes: ElementDefinitionType[],
     fisher: Fishable
   ): ElementTypeMatchInfo {
@@ -1193,6 +1219,15 @@ export class ElementDefinition {
             t2.code === 'canonical' &&
             (t2.targetProfile == null || t2.targetProfile.includes(md.url))
         );
+      } else if (type.isCodeableReference) {
+        // CodeableReferences always have a code 'CodeableReference' w/ the referenced type's defining URL set as
+        // one of the targetProfiles.  If the targetProfile property is null, that means any
+        // CodeableReference reference is allowed.
+        matchedType = targetTypes.find(
+          t2 =>
+            t2.code === 'CodeableReference' &&
+            (t2.targetProfile == null || t2.targetProfile.includes(md.url))
+        );
       } else {
         // Look for exact match on the code (w/ no profile) or a match on an allowed base type with
         // a matching profile
@@ -1227,6 +1262,8 @@ export class ElementDefinition {
         typeString = `Reference(${type.type})`;
       } else if (type.isCanonical) {
         typeString = `Canonical(${type.type})`;
+      } else if (type.isCodeableReference) {
+        typeString = `CodeableReference(${type.type})`;
       } else {
         typeString = type.type;
       }

src/fshtypes/common.ts

@@ -4,12 +4,15 @@ import { findLast } from 'lodash';
 export function typeString(types: OnlyRuleType[]): string {
   const references: OnlyRuleType[] = [];
   const canonicals: OnlyRuleType[] = [];
+  const codeableReferences: OnlyRuleType[] = [];
   const normals: OnlyRuleType[] = [];
   types.forEach(t => {
     if (t.isReference) {
       references.push(t);
     } else if (t.isCanonical) {
       canonicals.push(t);
+    } else if (t.isCodeableReference) {
+      codeableReferences.push(t);
     } else {
       normals.push(t);
     }
@@ -21,7 +24,12 @@ export function typeString(types: OnlyRuleType[]): string {
   const canonicalString = canonicals.length
     ? `Canonical(${canonicals.map(t => t.type).join(' or ')})`
     : '';
-  return [normalString, referenceString, canonicalString].filter(s => s).join(' or ');
+  const codeableReferenceString = codeableReferences.length
+    ? `CodeableReference(${codeableReferences.map(t => t.type).join(' or ')})`
+    : '';
+  return [normalString, referenceString, canonicalString, codeableReferenceString]
+    .filter(s => s)
+    .join(' or ');
 }
 
 // Adds expected backslash-escapes to a string to make it a FSH string

src/fshtypes/rules/OnlyRule.ts

@@ -21,4 +21,5 @@ export type OnlyRuleType = {
   type: string;
   isReference?: boolean;
   isCanonical?: boolean;
+  isCodeableReference?: boolean;
 };

src/import/FSHImporter.ts

@@ -1600,6 +1600,15 @@ export class FSHImporter extends FSHVisitor {
             isReference: true
           })
         );
+      } else if (t.codeableReferenceType()) {
+        const codeableReferenceToken = t.codeableReferenceType().CODEABLE_REFERENCE();
+        const codeableReferences = this.parseOrReference(codeableReferenceToken.getText());
+        codeableReferences.forEach(r =>
+          orTypes.push({
+            type: this.aliasAwareValue(codeableReferenceToken, r),
+            isCodeableReference: true
+          })
+        );
       } else if (t.canonical()) {
         const canonicals = this.visitCanonical(t.canonical());
         canonicals.forEach(c =>

src/import/generated/FSH.tokens

@@ -64,24 +64,25 @@ DATETIME=63
 TIME=64
 CARD=65
 REFERENCE=66
-CANONICAL=67
-CARET_SEQUENCE=68
-REGEX=69
-BLOCK_COMMENT=70
-SEQUENCE=71
-WHITESPACE=72
-LINE_COMMENT=73
-PARAM_RULESET_REFERENCE=74
-RULESET_REFERENCE=75
-BRACKETED_PARAM=76
-LAST_BRACKETED_PARAM=77
-PLAIN_PARAM=78
-LAST_PLAIN_PARAM=79
-QUOTED_CONTEXT=80
-LAST_QUOTED_CONTEXT=81
-UNQUOTED_CONTEXT=82
-LAST_UNQUOTED_CONTEXT=83
-CONTEXT_WHITESPACE=84
+CODEABLE_REFERENCE=67
+CANONICAL=68
+CARET_SEQUENCE=69
+REGEX=70
+BLOCK_COMMENT=71
+SEQUENCE=72
+WHITESPACE=73
+LINE_COMMENT=74
+PARAM_RULESET_REFERENCE=75
+RULESET_REFERENCE=76
+BRACKETED_PARAM=77
+LAST_BRACKETED_PARAM=78
+PLAIN_PARAM=79
+LAST_PLAIN_PARAM=80
+QUOTED_CONTEXT=81
+LAST_QUOTED_CONTEXT=82
+UNQUOTED_CONTEXT=83
+LAST_UNQUOTED_CONTEXT=84
+CONTEXT_WHITESPACE=85
 '?!'=24
 'MS'=25
 'SU'=26