chore(web): further PR cleanup

common/web/keyboard-processor/src/text/outputTarget.ts

@@ -1,7 +1,7 @@
 ///<reference types="@keymanapp/models-types" />
 
 import { extendString } from "@keymanapp/web-utils";
-import { searchStringDivergence } from "./stringDivergence.js";
+import { findCommonSubstringEndIndex } from "./stringDivergence.js";
 
 extendString();
 
@@ -124,14 +124,14 @@ export default abstract class OutputTarget {
     const toLeft = this.getTextBeforeCaret();
     const fromLeft = original.getTextBeforeCaret();
 
-    const leftDivergenceIndex = searchStringDivergence(fromLeft, toLeft, false);
+    const leftDivergenceIndex = findCommonSubstringEndIndex(fromLeft, toLeft, false);
     const deletedLeft = fromLeft.substring(leftDivergenceIndex)._kmwLength();
     // No need for our specialized variant here.
     const insertedText = toLeft.substring(leftDivergenceIndex);
 
     const toRight = this.getTextAfterCaret();
     const fromRight = original.getTextAfterCaret();
-    const rightDivergenceIndex = searchStringDivergence(fromRight, toRight, true);
+    const rightDivergenceIndex = findCommonSubstringEndIndex(fromRight, toRight, true);
 
     // Right insertions aren't supported, but right deletions will matter in some scenarios.
     // In particular, once we allow right-deletion for pred-text suggestions applied with the

common/web/keyboard-processor/src/text/stringDivergence.ts

@@ -1,11 +1,15 @@
+// Future TODO:  import from @keymanapp/common-types... once we no longer need to support ES5.
+import { Uni_IsSurrogate1, Uni_IsSurrogate2 } from '@keymanapp/web-utils';
+
 /**
- * Returns the index for the code point divergence point in code unit coordinates.
+ * Returns the index for the code point divergence point between two strings, as measured in code
+ * unit coordinates.
  * @param str1
  * @param str2
  * @param commonSuffix If false, asserts a common prefix to the strings.  If true, asserts a common suffix.
  * @returns The code unit index within `str1` for the start of the code point not common to both.
  */
-export function searchStringDivergence(str1: string, str2: string, commonSuffix: boolean): number {
+export function findCommonSubstringEndIndex(str1: string, str2: string, commonSuffix: boolean): number {
   /**
    * The maximum number of iterations to consider; exceeding this would go past a string boundary.
    */
@@ -67,16 +71,15 @@ export function searchStringDivergence(str1: string, str2: string, commonSuffix:
     const divergentChar1 = str1.charCodeAt(index);
     const divergentChar2 = str2.charCodeAt(index + offset);
 
-    const isHigh = (charCode: number) => charCode >= 0xD800 && charCode <= 0xDBFF;
-    const isLow =  (charCode: number) => charCode >= 0xDC00 && charCode <= 0xDFFF;
-    const commonChecker = commonSuffix ? isLow : isHigh;
-    const divergentChecker = commonSuffix ? isHigh : isLow;
+    const commonSurrogateChecker = commonSuffix ? Uni_IsSurrogate2 : Uni_IsSurrogate1;
+    const divergentSurrogateChecker = commonSuffix ? Uni_IsSurrogate1 : Uni_IsSurrogate2;
 
-    // If the last common char qualifies as a direction-appropriate SMP surrogate...
-    if(commonChecker(commonPotentialSurrogate)) {
+    // If the last common character if of the direction-appropriate surrogate type (for
+    // comprising a potential split surrogate pair representing a non-BMP char)...
+    if(commonSurrogateChecker(commonPotentialSurrogate)) {
       // And one of the two divergent chars is a qualifying match - a surrogate
       // of the opposite type...
-      if(divergentChecker(divergentChar1) || divergentChecker(divergentChar2)) {
+      if(divergentSurrogateChecker(divergentChar1) || divergentSurrogateChecker(divergentChar2)) {
         // Our current index would split a surrogate pair; decrement the index to
         // preserve the pair.
         return index - inc;

common/web/keyboard-processor/tests/node/transcriptions.js

@@ -7,11 +7,11 @@ extendString();  // Ensure KMW's string-extension functionality is available.
 
 String.kmwEnableSupplementaryPlane(false);
 
-// A unicode-coding like alias for use in constructing SMP strings.
+// A unicode-coding like alias for use in constructing non-BMP strings.
 const u = String.fromCodePoint;
 
 /**
- * Returns the "Mathematical Sans-Serif Small" SMP encoding for
+ * Returns the "Mathematical Sans-Serif Small" non-BMP encoding for
  * a passed-in lowercase char between 'a' and 'z', inclusive.
  * @param {*} char
  * @returns
@@ -39,7 +39,7 @@ describe("String divergence calculations", function() {
       assert.equal(result2, 0);
     });
 
-    it("SMP text", () => {
+    it("non-BMP text", () => {
       const smp_ify = (str) => str.split('').map(ss).join('');
 
       const result1 = searchStringDivergence(
@@ -48,7 +48,7 @@ describe("String divergence calculations", function() {
         false
       );
 
-      // 2 per SMP char; is in code-unit... units.
+      // 2 per non-BMP char; is in code-unit... units.
       // Will avoid splitting code points, though.
       assert.equal(result1, 8);
 
@@ -61,7 +61,7 @@ describe("String divergence calculations", function() {
       assert.equal(result2, 8);
     });
 
-    it("SMP edge cases", () => {
+    it("non-BMP edge cases", () => {
       const smp_ify = (str) => str.split('').map(ss).join('');
 
       const result1 = searchStringDivergence(
@@ -106,7 +106,7 @@ describe("String divergence calculations", function() {
       assert.equal(result2, "post-caret text".length-1);
     })
 
-    it("SMP text", () => {
+    it("non-BMP text", () => {
       const smp_ify = (str) => str.split('').map(ss).join('');
 
       //   att|endance
@@ -117,7 +117,7 @@ describe("String divergence calculations", function() {
         true
       );
 
-      // 2 per SMP char; is in code-unit... units.
+      // 2 per non-BMP char; is in code-unit... units.
       // Will avoid splitting code points; is odd b/c we get the index of the LAST char of the pair.
       assert.equal(result1, 5);
 
@@ -132,7 +132,7 @@ describe("String divergence calculations", function() {
 
     });
 
-    it("SMP edge cases", () => {
+    it("non-BMP edge cases", () => {
       const smp_ify = (str) => str.split('').map(ss).join('');
 
       // If the two are equal...
@@ -155,7 +155,7 @@ describe("String divergence calculations", function() {
 });
 
 describe("Transcriptions and Transforms", function() {
-  // Built in-line via function.  Looks functionally equivalent to "apple", but with SMP characters.
+  // Built in-line via function.  Looks functionally equivalent to "apple", but with non-BMP characters.
   let smpApple = u(0x1d5ba)+u(0x1d5c9)+u(0x1d5c9)+u(0x1d5c5)+u(0x1d5be);
 
   it("does not store an alias for related OutputTargets", function() {
@@ -263,7 +263,7 @@ but not himself.`;  // Sheev Palpatine, in the Star Wars prequels.
       assert.equal(transcription.transform.deleteRight, 1, "Incorrect count for right-of-caret deletions");
     });
 
-    it("handles deletions around the caret without text insertion (SMP text)", function() {
+    it("handles deletions around the caret without text insertion (non-BMP text)", function() {
       try {
         String.kmwEnableSupplementaryPlane(true);
         var target = new Mock(smpApple, 2);
@@ -355,7 +355,7 @@ but not himself.`;  // Sheev Palpatine, in the Star Wars prequels.
       assert.equal(transcription.transform.deleteRight, 3, "Incorrect count for right-of-caret deletions");
     });
 
-    it("handles deletions around the caret with text insertion (SMP text)", function() {
+    it("handles deletions around the caret with text insertion (non-BMP text)", function() {
       try {
         String.kmwEnableSupplementaryPlane(true);
 

common/web/utils/src/index.ts

@@ -21,6 +21,8 @@ export { default as extendString } from "./kmwstring.js";
 export { default as ManagedPromise } from "./managedPromise.js";
 export { default as TimeoutPromise, timedPromise } from "./timeoutPromise.js";
 
+export { Uni_IsSurrogate1, Uni_IsSurrogate2 } from "./surrogates.js";
+
 // // Uncomment the following line and run the bundled output to verify successful
 // // esbuild bundling of this submodule:
 // console.log(Version.CURRENT.toString());

common/web/utils/src/surrogates.ts

@@ -0,0 +1,27 @@
+/*
+ * The definitions below are duplicated from common/web/types/util/util.ts;
+ * we can't downcompile the originals to ES5 when bundling with esbuild.
+ * `import type` stuff is fine, but not non-type `import` statements.
+ *
+ * TODO:  Use those instead, once we're no longer building ES5 versions of Web.
+ */
+
+export const Uni_LEAD_SURROGATE_START = 0xD800;
+export const Uni_LEAD_SURROGATE_END = 0xDBFF;
+export const Uni_TRAIL_SURROGATE_START = 0xDC00;
+export const Uni_TRAIL_SURROGATE_END = 0xDFFF;
+
+/**
+ * @brief True if a lead surrogate
+ * \def Uni_IsSurrogate1
+ */
+export function Uni_IsSurrogate1(ch : number) {
+  return ((ch) >= Uni_LEAD_SURROGATE_START && (ch) <= Uni_LEAD_SURROGATE_END);
+}
+/**
+ * @brief True if a trail surrogate
+ * \def Uni_IsSurrogate2
+ */
+export function Uni_IsSurrogate2(ch : number) {
+  return ((ch) >= Uni_TRAIL_SURROGATE_START && (ch) <= Uni_TRAIL_SURROGATE_END);
+}