First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

client/node_modules/path-data-parser/src/parser.ts

@@ -0,0 +1,113 @@
+const COMMAND = 0;
+const NUMBER = 1;
+const EOD = 2;
+type TokenType = 0 | 1 | 2;
+
+interface PathToken {
+  type: TokenType;
+  text: string;
+}
+
+export interface Segment {
+  key: string;
+  data: number[];
+}
+
+const PARAMS: { [key: string]: number } = { A: 7, a: 7, C: 6, c: 6, H: 1, h: 1, L: 2, l: 2, M: 2, m: 2, Q: 4, q: 4, S: 4, s: 4, T: 2, t: 2, V: 1, v: 1, Z: 0, z: 0 };
+
+function tokenize(d: string): PathToken[] {
+  const tokens: PathToken[] = new Array();
+  while (d !== '') {
+    if (d.match(/^([ \t\r\n,]+)/)) {
+      d = d.substr(RegExp.$1.length);
+    } else if (d.match(/^([aAcChHlLmMqQsStTvVzZ])/)) {
+      tokens[tokens.length] = { type: COMMAND, text: RegExp.$1 };
+      d = d.substr(RegExp.$1.length);
+    } else if (d.match(/^(([-+]?[0-9]+(\.[0-9]*)?|[-+]?\.[0-9]+)([eE][-+]?[0-9]+)?)/)) {
+      tokens[tokens.length] = { type: NUMBER, text: `${parseFloat(RegExp.$1)}` };
+      d = d.substr(RegExp.$1.length);
+    } else {
+      return [];
+    }
+  }
+  tokens[tokens.length] = { type: EOD, text: '' };
+  return tokens;
+}
+
+function isType(token: PathToken, type: number) {
+  return token.type === type;
+}
+
+export function parsePath(d: string): Segment[] {
+  const segments: Segment[] = [];
+  const tokens = tokenize(d);
+  let mode = 'BOD';
+  let index = 0;
+  let token = tokens[index];
+  while (!isType(token, EOD)) {
+    let paramsCount = 0;
+    const params: number[] = [];
+    if (mode === 'BOD') {
+      if (token.text === 'M' || token.text === 'm') {
+        index++;
+        paramsCount = PARAMS[token.text];
+        mode = token.text;
+      } else {
+        return parsePath('M0,0' + d);
+      }
+    } else if (isType(token, NUMBER)) {
+      paramsCount = PARAMS[mode];
+    } else {
+      index++;
+      paramsCount = PARAMS[token.text];
+      mode = token.text;
+    }
+    if ((index + paramsCount) < tokens.length) {
+      for (let i = index; i < index + paramsCount; i++) {
+        const numbeToken = tokens[i];
+        if (isType(numbeToken, NUMBER)) {
+          params[params.length] = +numbeToken.text;
+        }
+        else {
+          throw new Error('Param not a number: ' + mode + ',' + numbeToken.text);
+        }
+      }
+      if (typeof PARAMS[mode] === 'number') {
+        const segment: Segment = { key: mode, data: params };
+        segments.push(segment);
+        index += paramsCount;
+        token = tokens[index];
+        if (mode === 'M') mode = 'L';
+        if (mode === 'm') mode = 'l';
+      } else {
+        throw new Error('Bad segment: ' + mode);
+      }
+    } else {
+      throw new Error('Path data ended short');
+    }
+  }
+  return segments;
+}
+
+export function serialize(segments: Segment[]): string {
+  const tokens: (string | number)[] = [];
+  for (const { key, data } of segments) {
+    tokens.push(key);
+    switch (key) {
+      case 'C':
+      case 'c':
+        tokens.push(data[0], `${data[1]},`, data[2], `${data[3]},`, data[4], data[5]);
+        break;
+      case 'S':
+      case 's':
+      case 'Q':
+      case 'q':
+        tokens.push(data[0], `${data[1]},`, data[2], data[3]);
+        break;
+      default:
+        tokens.push(...data);
+        break;
+    }
+  }
+  return tokens.join(' ');
+}