.

qwen/nodejs/node_modules/graphemer/lib/GraphemerHelper.js

@@ -0,0 +1,169 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const boundaries_1 = require("./boundaries");
+// BreakTypes
+// @type {BreakType}
+const NotBreak = 0;
+const BreakStart = 1;
+const Break = 2;
+const BreakLastRegional = 3;
+const BreakPenultimateRegional = 4;
+class GraphemerHelper {
+    /**
+     * Check if the the character at the position {pos} of the string is surrogate
+     * @param str {string}
+     * @param pos {number}
+     * @returns {boolean}
+     */
+    static isSurrogate(str, pos) {
+        return (0xd800 <= str.charCodeAt(pos) &&
+            str.charCodeAt(pos) <= 0xdbff &&
+            0xdc00 <= str.charCodeAt(pos + 1) &&
+            str.charCodeAt(pos + 1) <= 0xdfff);
+    }
+    /**
+     * The String.prototype.codePointAt polyfill
+     * Private function, gets a Unicode code point from a JavaScript UTF-16 string
+     * handling surrogate pairs appropriately
+     * @param str {string}
+     * @param idx {number}
+     * @returns {number}
+     */
+    static codePointAt(str, idx) {
+        if (idx === undefined) {
+            idx = 0;
+        }
+        const code = str.charCodeAt(idx);
+        // if a high surrogate
+        if (0xd800 <= code && code <= 0xdbff && idx < str.length - 1) {
+            const hi = code;
+            const low = str.charCodeAt(idx + 1);
+            if (0xdc00 <= low && low <= 0xdfff) {
+                return (hi - 0xd800) * 0x400 + (low - 0xdc00) + 0x10000;
+            }
+            return hi;
+        }
+        // if a low surrogate
+        if (0xdc00 <= code && code <= 0xdfff && idx >= 1) {
+            const hi = str.charCodeAt(idx - 1);
+            const low = code;
+            if (0xd800 <= hi && hi <= 0xdbff) {
+                return (hi - 0xd800) * 0x400 + (low - 0xdc00) + 0x10000;
+            }
+            return low;
+        }
+        // just return the char if an unmatched surrogate half or a
+        // single-char codepoint
+        return code;
+    }
+    //
+    /**
+     * Private function, returns whether a break is allowed between the two given grapheme breaking classes
+     * Implemented the UAX #29 3.1.1 Grapheme Cluster Boundary Rules on extended grapheme clusters
+     * @param start {number}
+     * @param mid {Array<number>}
+     * @param end {number}
+     * @param startEmoji {number}
+     * @param midEmoji {Array<number>}
+     * @param endEmoji {number}
+     * @returns {number}
+     */
+    static shouldBreak(start, mid, end, startEmoji, midEmoji, endEmoji) {
+        const all = [start].concat(mid).concat([end]);
+        const allEmoji = [startEmoji].concat(midEmoji).concat([endEmoji]);
+        const previous = all[all.length - 2];
+        const next = end;
+        const nextEmoji = endEmoji;
+        // Lookahead terminator for:
+        // GB12. ^ (RI RI)* RI ? RI
+        // GB13. [^RI] (RI RI)* RI ? RI
+        const rIIndex = all.lastIndexOf(boundaries_1.CLUSTER_BREAK.REGIONAL_INDICATOR);
+        if (rIIndex > 0 &&
+            all.slice(1, rIIndex).every(function (c) {
+                return c === boundaries_1.CLUSTER_BREAK.REGIONAL_INDICATOR;
+            }) &&
+            [boundaries_1.CLUSTER_BREAK.PREPEND, boundaries_1.CLUSTER_BREAK.REGIONAL_INDICATOR].indexOf(previous) === -1) {
+            if (all.filter(function (c) {
+                return c === boundaries_1.CLUSTER_BREAK.REGIONAL_INDICATOR;
+            }).length %
+                2 ===
+                1) {
+                return BreakLastRegional;
+            }
+            else {
+                return BreakPenultimateRegional;
+            }
+        }
+        // GB3. CR × LF
+        if (previous === boundaries_1.CLUSTER_BREAK.CR && next === boundaries_1.CLUSTER_BREAK.LF) {
+            return NotBreak;
+        }
+        // GB4. (Control|CR|LF) ÷
+        else if (previous === boundaries_1.CLUSTER_BREAK.CONTROL ||
+            previous === boundaries_1.CLUSTER_BREAK.CR ||
+            previous === boundaries_1.CLUSTER_BREAK.LF) {
+            return BreakStart;
+        }
+        // GB5. ÷ (Control|CR|LF)
+        else if (next === boundaries_1.CLUSTER_BREAK.CONTROL ||
+            next === boundaries_1.CLUSTER_BREAK.CR ||
+            next === boundaries_1.CLUSTER_BREAK.LF) {
+            return BreakStart;
+        }
+        // GB6. L × (L|V|LV|LVT)
+        else if (previous === boundaries_1.CLUSTER_BREAK.L &&
+            (next === boundaries_1.CLUSTER_BREAK.L ||
+                next === boundaries_1.CLUSTER_BREAK.V ||
+                next === boundaries_1.CLUSTER_BREAK.LV ||
+                next === boundaries_1.CLUSTER_BREAK.LVT)) {
+            return NotBreak;
+        }
+        // GB7. (LV|V) × (V|T)
+        else if ((previous === boundaries_1.CLUSTER_BREAK.LV || previous === boundaries_1.CLUSTER_BREAK.V) &&
+            (next === boundaries_1.CLUSTER_BREAK.V || next === boundaries_1.CLUSTER_BREAK.T)) {
+            return NotBreak;
+        }
+        // GB8. (LVT|T) × (T)
+        else if ((previous === boundaries_1.CLUSTER_BREAK.LVT || previous === boundaries_1.CLUSTER_BREAK.T) &&
+            next === boundaries_1.CLUSTER_BREAK.T) {
+            return NotBreak;
+        }
+        // GB9. × (Extend|ZWJ)
+        else if (next === boundaries_1.CLUSTER_BREAK.EXTEND || next === boundaries_1.CLUSTER_BREAK.ZWJ) {
+            return NotBreak;
+        }
+        // GB9a. × SpacingMark
+        else if (next === boundaries_1.CLUSTER_BREAK.SPACINGMARK) {
+            return NotBreak;
+        }
+        // GB9b. Prepend ×
+        else if (previous === boundaries_1.CLUSTER_BREAK.PREPEND) {
+            return NotBreak;
+        }
+        // GB11. \p{Extended_Pictographic} Extend* ZWJ × \p{Extended_Pictographic}
+        const previousNonExtendIndex = allEmoji
+            .slice(0, -1)
+            .lastIndexOf(boundaries_1.EXTENDED_PICTOGRAPHIC);
+        if (previousNonExtendIndex !== -1 &&
+            allEmoji[previousNonExtendIndex] === boundaries_1.EXTENDED_PICTOGRAPHIC &&
+            all.slice(previousNonExtendIndex + 1, -2).every(function (c) {
+                return c === boundaries_1.CLUSTER_BREAK.EXTEND;
+            }) &&
+            previous === boundaries_1.CLUSTER_BREAK.ZWJ &&
+            nextEmoji === boundaries_1.EXTENDED_PICTOGRAPHIC) {
+            return NotBreak;
+        }
+        // GB12. ^ (RI RI)* RI × RI
+        // GB13. [^RI] (RI RI)* RI × RI
+        if (mid.indexOf(boundaries_1.CLUSTER_BREAK.REGIONAL_INDICATOR) !== -1) {
+            return Break;
+        }
+        if (previous === boundaries_1.CLUSTER_BREAK.REGIONAL_INDICATOR &&
+            next === boundaries_1.CLUSTER_BREAK.REGIONAL_INDICATOR) {
+            return NotBreak;
+        }
+        // GB999. Any ? Any
+        return BreakStart;
+    }
+}
+exports.default = GraphemerHelper;