Merge pull request #53 from HL7/feature/LF-1450/implement-conversion-…

…functions

Feature/lf 1450/implement conversion functions

CHANGELOG.md

@@ -3,6 +3,17 @@
 This log documents significant changes for each release. This project follows
 [Semantic Versioning](http://semver.org/).
 
+## [2.3.0] - 2020-06-17
+### Added
+- Functions: toBoolean(), convertsToBoolean(), convertsToInteger(), convertsToDecimal(), convertsToString(),
+ convertsToDateTime(), convertsToTime(), convertsToQuantity()
+### Fixed
+- toInteger() function should return an empty collection for non-convertible string
+- toQuantity() function should work with the entire input string, not part of it (RegExp expression surrounded with ^...$)
+- toQuantity() function should support boolean values
+- toQuantity() function should not accept a string where UCUM unit code is not surrounded with single quotes
+- The third parameter of iif function should be optional
+
 ## [2.2.2] - 2020-06-05
 ### Fixed
 - Updated FHIRPath test cases

README.md

@@ -118,8 +118,9 @@ fhirpath --expression 'Patient.name.given'
 
 ## Implementation Status
 
-We are currently implementing version 1.0 (a.k.a STU1) of
-[FHIRPath](http://hl7.org/fhirpath/).
+We are currently working on implementing version 2.0.0 of
+[FHIRPath](http://hl7.org/fhirpath/);
+some behavior may still be following the previous version, STU1.
 
 The core parser was generated from the FHIRPath ANTLR grammar.
 
@@ -143,7 +144,7 @@ Completed sections:
 - 9 (Environment Variables)
 
 Almost completed sections:
-- 5.5 (Conversion) - unimplemented methods: toBoolean, toDate.
+- 5.5 (Conversion) - unimplemented methods: toDate, convertsToDate.
 
 We are deferring handling information about FHIR resources, as much as
 possible, with the exception of support for choice types. This affects

package.json

@@ -1,6 +1,6 @@
 {
  "name": "fhirpath",
- "version": "2.2.2",
+ "version": "2.3.0",
  "description": "A FHIRPath engine",
  "main": "src/fhirpath.js",
  "dependencies": {

src/fhirpath.js

@@ -82,14 +82,22 @@ engine.invocationTable = {
  take: {fn: filtering.takeFn, arity: {1: ["Integer"]}},
  skip: {fn: filtering.skipFn, arity: {1: ["Integer"]}},
  combine: {fn: combining.combineFn, arity: {1: ["AnyAtRoot"]}},
- iif: {fn: misc.iifMacro, arity: {3: ["Expr", "Expr", "Expr"]}},
+ iif: {fn: misc.iifMacro, arity: {2: ["Expr", "Expr"], 3: ["Expr", "Expr", "Expr"]}},
  trace: {fn: misc.traceFn, arity: {0: [], 1: ["String"]}},
  toInteger: {fn: misc.toInteger},
  toDecimal: {fn: misc.toDecimal},
  toString: {fn: misc.toString},
  toDateTime: {fn: misc.toDateTime},
  toTime: {fn: misc.toTime},
+ toBoolean: {fn: misc.toBoolean},
  toQuantity: {fn: misc.toQuantity, arity: {0: [], 1: ["String"]}},
+ convertsToBoolean: {fn: misc.createConvertsToFn(misc.toBoolean, 'boolean')},
+ convertsToInteger: {fn: misc.createConvertsToFn(misc.toInteger, 'number')},
+ convertsToDecimal: {fn: misc.createConvertsToFn(misc.toDecimal, 'number')},
+ convertsToString: {fn: misc.createConvertsToFn(misc.toString, 'string')},
+ convertsToDateTime: {fn: misc.createConvertsToFn(misc.toDateTime, FP_DateTime)},
+ convertsToTime: {fn: misc.createConvertsToFn(misc.toTime, FP_Time)},
+ convertsToQuantity: {fn: misc.createConvertsToFn(misc.toQuantity, FP_Quantity)},
 
  indexOf: {fn: strings.indexOf, arity: {1: ["String"]}},
  substring: {fn: strings.substring, arity: {1: ["Integer"], 2: ["Integer","Integer"]}},

src/misc.js

@@ -13,7 +13,7 @@ engine.iifMacro = function(data, cond, ok, fail) {
  if(util.isTrue(cond(data))) {
  return ok(data);
  } else {
- return fail(data);
+ return fail ? fail(data) : [];
  }
 };
 
@@ -38,17 +38,19 @@ engine.toInteger = function(coll){
  if(typeof v === "string") {
  if(intRegex.test(v)){
  return parseInt(v);
- } else {
- throw new Error("Could not convert to ineger: " + v);
  }
  }
  return [];
 };
 
-const quantityRegex = /((\+|-)?\d+(\.\d+)?)\s*(('[^']+')|([a-zA-Z]+))?/,
+const quantityRegex = /^((\+|-)?\d+(\.\d+)?)\s*(('[^']+')|([a-zA-Z]+))?$/,
  quantityRegexMap = {value:1,unit:5,time:6};
 engine.toQuantity = function (coll, toUnit) {
  let result;
+ // Surround UCUM unit code in the toUnit parameter with single quotes
+ if (toUnit && !FP_Quantity.mapTimeUnitsToUCUMCode[toUnit]) {
+ toUnit = `'${toUnit}'`;
+ }
 
  if (coll.length > 1) {
  throw new Error("Could not convert to quantity: input collection contains multiple items");
@@ -61,12 +63,17 @@ engine.toQuantity = function (coll, toUnit) {
  result = new FP_Quantity(v, '\'1\'');
  } else if (v instanceof FP_Quantity) {
  result = v;
+ } else if (typeof v === 'boolean') {
+ result = new FP_Quantity(v ? 1 : 0, '\'1\'');
  } else if (typeof v === "string" && (quantityRegexRes = quantityRegex.exec(v)) ) {
  const value = quantityRegexRes[quantityRegexMap.value],
  unit = quantityRegexRes[quantityRegexMap.unit],
  time = quantityRegexRes[quantityRegexMap.time];
 
- result = new FP_Quantity(Number(value), unit||time||'\'1\'');
+ // UCUM unit code in the input string must be surrounded with single quotes
+ if (!time || FP_Quantity.mapTimeUnitsToUCUMCode[time]) {
+ result = new FP_Quantity(Number(value), unit || time || '\'1\'');
+ }
  }
 
  if (result && toUnit && result.unit !== toUnit) {
@@ -116,12 +123,80 @@ function defineTimeConverter(timeType) {
  if (coll.length === 1) {
  var t = types[timeType].checkString(util.valData(coll[0]));
  if (t)
- rtn[0] = t;
+ rtn = t;
  }
  return rtn;
  };
 }
 defineTimeConverter('FP_DateTime');
 defineTimeConverter('FP_Time');
 
+// Possible string values convertible to the true boolean value
+const trueStrings = ['true', 't', 'yes', 'y', '1', '1.0'].reduce((acc, val) => {
+ acc[val] = true;
+ return acc;
+}, {});
+
+// Possible string values convertible to the false boolean value
+const falseStrings = ['false', 'f', 'no', 'n', '0', '0.0'].reduce((acc, val) => {
+ acc[val] = true;
+ return acc;
+}, {});
+
+engine.toBoolean = function (coll) {
+ if(coll.length !== 1) {
+ return [];
+ }
+
+ const v = util.valData(coll[0]);
+ switch (typeof v) {
+ case 'boolean':
+ return v;
+ case 'number':
+ if (v === 1) {
+ return true;
+ }
+ if (v === 0) {
+ return false;
+ }
+ break;
+ case 'string':
+ // eslint-disable-next-line no-case-declarations
+ const lowerCaseValue = v.toLowerCase();
+ if (trueStrings[lowerCaseValue]) {
+ return true;
+ }
+ if (falseStrings[lowerCaseValue]) {
+ return false;
+ }
+ }
+ return [];
+};
+
+/**
+ * Creates function that checks if toFunction returns specified type
+ * @param {function(coll: array): <type|[]>} toFunction
+ * @param {string|class} type - specifies type, for example: 'string' or FP_Quantity
+ * @return {function(coll: array)}
+ */
+engine.createConvertsToFn = function (toFunction, type) {
+ if (typeof type === 'string') {
+ return function (coll) {
+ if (coll.length !== 1) {
+ return [];
+ }
+
+ return typeof toFunction(coll) === type;
+ };
+ }
+
+ return function (coll) {
+ if (coll.length !== 1) {
+ return [];
+ }
+
+ return toFunction(coll) instanceof type;
+ };
+};
+
 module.exports = engine;

test/cases/5.5_conversion.yaml

@@ -30,6 +30,14 @@ tests:
  expression: Functions.iif(coll1[0].coll2[0].attr = 1, coll1[0].coll2[0].attr, coll1[0].coll2[1].attr)
  result: [1]
 
+ - desc: '** iif 4'
+ expression: Functions.iif(true, 'a')
+ result: ['a']
+
+ - desc: '** iif 5'
+ expression: Functions.iif(false, 'a')
+ result: []
+
  - desc: '5.5.2. toInteger() : integer'
  # If the input collection contains a single item, this functio# n will return a single integer if:
  # the item in the input collection is an integer
@@ -137,7 +145,12 @@ tests:
  - true
  - desc: '** string to Quantity'
  inputfile: patient-example.json
- expression: '''1 \''wk\''''.toQuantity(''\''d\'''') = 7 days'
+ expression: "'1 \\'wk\\''.toQuantity('d') = 7 days"
+ result:
+ - true
+ - desc: '** string to Quantity - result UCUM unit code must be surrounded with single quotes'
+ inputfile: patient-example.json
+ expression: "'1 \\'wk\\''.toQuantity('d').toString() = '7 \\'d\\''"
  result:
  - true
  - desc: '** calendar duration conversion factor'
@@ -152,12 +165,12 @@ tests:
  - true
  - desc: '** UCUM units'
  inputfile: patient-example.json
- expression: '''1 cm''.toQuantity(''\''mm\'''').value = 10'
+ expression: "'1 \\'cm\\''.toQuantity('mm').value = 10"
  result:
  - true
  - desc: '** Invalid conversion'
  inputfile: patient-example.json
- expression: '''1 cm''.toQuantity(''\''g\'''')'
+ expression: "'1 \\'cm\\''.toQuantity('g')"
  result: []
  - desc: '** Implicit to quantity + toQuantity'
  inputfile: observation-example.json