upper-case and lower-case (XSLT 2.0) (#77)

* Base implementation.
* Unit tests and adjustments.

Author: leonelsanchesdasilva

src/xpath/expr-context.ts

@@ -88,6 +88,7 @@ export class ExprContext {
     constructor(
         nodeList: XNode[],
         outputNodeList: XNode[],
+        xsltVersion: '1.0' | '2.0' | '3.0' = '1.0',
         opt_position?: number,
         opt_outputPosition?: number,
         opt_outputDepth?: number,
@@ -102,6 +103,8 @@ export class ExprContext {
     ) {
         this.nodeList = nodeList;
         this.outputNodeList = outputNodeList;
+        this.xsltVersion = xsltVersion;
+
         this.position = opt_position || 0;
         this.outputPosition = opt_outputPosition || 0;
 
@@ -158,6 +161,7 @@ export class ExprContext {
         return new ExprContext(
             opt_nodeList || this.nodeList,
             opt_outputNodeList || this.outputNodeList,
+            this.xsltVersion,
             typeof opt_position !== 'undefined' ? opt_position : this.position,
             typeof opt_outputPosition !== 'undefined' ? opt_outputPosition : this.outputPosition,
             this.outputDepth,
@@ -176,6 +180,7 @@ export class ExprContext {
         return new ExprContext(
             this.nodeList,
             opt_outputNodeList || this.outputNodeList,
+            this.xsltVersion,
             this.position,
             typeof opt_outputPosition !== 'undefined' ? opt_outputPosition : this.outputPosition,
             typeof opt_outputDepth !== 'undefined' ? opt_outputDepth : this.outputDepth,

src/xpath/expressions/function-call-expr.ts

@@ -35,6 +35,7 @@ import {
     formatNumber
 } from '../functions';
 import { extCardinal, extIf, extJoin } from '../functions/non-standard';
+import { lowerCase, upperCase } from '../functions/standard-20';
 import { BooleanValue } from '../values/boolean-value';
 import { Expression } from './expression';
 
@@ -58,6 +59,7 @@ export class FunctionCallExpr extends Expression {
         lang,
         last,
         'local-name': localName,
+        'lower-case': lowerCase,
         matches,
         name: _name,
         'namespace-uri': namespaceUri,
@@ -76,6 +78,7 @@ export class FunctionCallExpr extends Expression {
         'string-length': stringLength,
         translate,
         true: _true,
+        'upper-case': upperCase,
 
         // TODO(mesch): The following functions are custom. There is a
         // standard that defines how to add functions, which should be

src/xpath/functions/standard-20.ts

@@ -0,0 +1,15 @@
+import { ExprContext } from "../expr-context";
+import { StringValue } from "../values";
+import { assert } from "./internal-functions";
+
+export function upperCase(context: ExprContext) {
+    assert(['2.0', '3.0'].includes(context.xsltVersion));
+    const str: string = this.args[0].evaluate(context).stringValue();
+    return new StringValue(str.toUpperCase());
+}
+
+export function lowerCase(context: ExprContext) {
+    assert(['2.0', '3.0'].includes(context.xsltVersion));
+    const str: string = this.args[0].evaluate(context).stringValue();
+    return new StringValue(str.toLowerCase());
+}

src/xpath/values/boolean-value.ts

@@ -9,7 +9,7 @@ export class BooleanValue implements NodeValue {
         this.type = 'boolean';
     }
 
-    stringValue() {
+    stringValue(): string {
         return `${this.value}`;
     }
 

src/xpath/values/node-set-value.ts

@@ -10,7 +10,7 @@ export class NodeSetValue implements NodeValue {
         this.type = 'node-set';
     }
 
-    stringValue() {
+    stringValue(): string {
         if (this.value.length === 0) {
             return '';
         }

src/xpath/values/number-value.ts

@@ -9,7 +9,7 @@ export class NumberValue implements NodeValue {
         this.type = 'number';
     }
 
-    stringValue() {
+    stringValue(): string {
         return `${this.value}`;
     }
 

src/xpath/values/string-value.ts

@@ -9,8 +9,8 @@ export class StringValue implements NodeValue {
         this.type = 'string';
     }
 
-    stringValue() {
-        return this.value;
+    stringValue(): string {
+        return String(this.value);
     }
 
     booleanValue() {