M3(1/5): @sfeel —— S-FEEL 子集的解析与求值,前后端同源

- lexer / parser(递归下降)/ evaluate / static-check,四文件纯函数,零 IO 零外部调用 - 子集封顶(ADR-006):比较 · 逻辑 · 算术 · 区间(开闭四态)· 列表与 in · 封闭内建函数集(字符串 / 数字 / 日期);未知函数一律拦下 - 单元格谓词(DMN 一格):`-` 任意 / 比较 / 区间 / 逗号析取 - staticCheck 给「画图即校验」用:语法 + 未知函数 + 引用路径清单 - app 侧以它替下 passthroughEvaluator:监听内容条件真求值,求值异常按不命中处置并留痕 32 个 sfeel 测试;全仓 182 个测试通过,门禁五道全绿 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KeDBx2PHLavbURXB8LJJ7m
2026-07-27 01:21:45 +08:00
parent f0444f1417
commit 146e9bbfad
13 changed files with 1048 additions and 26 deletions
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+/**
+ * S-FEEL 子集的词法分析 —— 纯函数(编码规范 §8.3;定义域 OS 03)。
+ *
+ * 子集范围:比较、逻辑、算术、字符串与日期函数,**无外部调用,静态可检**。
+ */
+
+export const TOKEN_KINDS = [
+  'number',
+  'string',
+  'name',
+  'punct',
+  'eof',
+] as const;
+export type TokenKind = (typeof TOKEN_KINDS)[number];
+
+export type Token = {
+  readonly kind: TokenKind;
+  readonly text: string;
+  readonly value?: number | string;
+  readonly pos: number;
+};
+
+export class SfeelSyntaxError extends Error {
+  constructor(
+    message: string,
+    readonly pos: number,
+  ) {
+    super(`S-FEEL 语法错误(第 ${pos} 字符):${message}`);
+    this.name = 'SfeelSyntaxError';
+  }
+}
+
+/** 多字符符号先于单字符匹配 */
+const PUNCT = ['<=', '>=', '!=', '==', '..', '<', '>', '=', '+', '-', '*', '/', '(', ')', '[', ']', ',', '.'] as const;
+
+const NAME_START = /[A-Za-z_一-龥]/;
+const NAME_PART = /[A-Za-z0-9_一-龥]/;
+
+export function tokenize(source: string): Token[] {
+  const tokens: Token[] = [];
+  let i = 0;
+
+  while (i < source.length) {
+    const ch = source[i]!;
+
+    if (/\s/.test(ch)) {
+      i += 1;
+      continue;
+    }
+
+    // 字符串:单引号或双引号,支持 \" \\ \n \t
+    if (ch === '"' || ch === "'") {
+      const quote = ch;
+      const start = i;
+      i += 1;
+      let value = '';
+      while (i < source.length && source[i] !== quote) {
+        if (source[i] === '\\') {
+          const next = source[i + 1];
+          value +=
+            next === 'n' ? '\n' : next === 't' ? '\t' : next === '\\' ? '\\' : next === quote ? quote : (next ?? '');
+          i += 2;
+          continue;
+        }
+        value += source[i];
+        i += 1;
+      }
+      if (i >= source.length) throw new SfeelSyntaxError('字符串未闭合', start);
+      i += 1;
+      tokens.push({ kind: 'string', text: source.slice(start, i), value, pos: start });
+      continue;
+    }
+
+    // 数字:整数、小数;不支持科学计数(子集封顶)
+    if (/[0-9]/.test(ch)) {
+      const start = i;
+      while (i < source.length && /[0-9]/.test(source[i]!)) i += 1;
+      // `..` 是区间符号,不是小数点
+      if (source[i] === '.' && source[i + 1] !== '.') {
+        i += 1;
+        while (i < source.length && /[0-9]/.test(source[i]!)) i += 1;
+      }
+      const text = source.slice(start, i);
+      tokens.push({ kind: 'number', text, value: Number(text), pos: start });
+      continue;
+    }
+
+    // 名字:标识符与关键字;允许空格分隔的多词函数名(如 `starts with`)在 parser 里合并
+    if (NAME_START.test(ch)) {
+      const start = i;
+      while (i < source.length && NAME_PART.test(source[i]!)) i += 1;
+      tokens.push({ kind: 'name', text: source.slice(start, i), pos: start });
+      continue;
+    }
+
+    const punct = PUNCT.find((p) => source.startsWith(p, i));
+    if (punct !== undefined) {
+      tokens.push({ kind: 'punct', text: punct, pos: i });
+      i += punct.length;
+      continue;
+    }
+
+    throw new SfeelSyntaxError(`无法识别的字符 ${JSON.stringify(ch)}`, i);
+  }
+
+  tokens.push({ kind: 'eof', text: '', pos: source.length });
+  return tokens;
+}