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

packages/sfeel/src/ast.ts

@@ -0,0 +1,32 @@
+/**
+ * S-FEEL 子集的抽象语法树(编码规范 §8.3)。
+ * AST 是可 diff、可静态检查的中间形态 —— 前端画布的即时校验与后端裁决同源。
+ */
+
+export type Node =
+  | { readonly kind: 'literal'; readonly value: number | string | boolean | null }
+  | { readonly kind: 'path'; readonly segments: readonly string[] }
+  | { readonly kind: 'unary'; readonly op: '-' | 'not'; readonly operand: Node }
+  | {
+      readonly kind: 'binary';
+      readonly op: '+' | '-' | '*' | '/' | '=' | '!=' | '<' | '<=' | '>' | '>=' | 'and' | 'or';
+      readonly left: Node;
+      readonly right: Node;
+    }
+  | { readonly kind: 'list'; readonly items: readonly Node[] }
+  | {
+      readonly kind: 'range';
+      readonly startOpen: boolean;
+      readonly endOpen: boolean;
+      readonly start: Node;
+      readonly end: Node;
+    }
+  | { readonly kind: 'in'; readonly value: Node; readonly candidates: Node }
+  | { readonly kind: 'call'; readonly name: string; readonly args: readonly Node[] };
+
+/** 单元格谓词(DMN 决策表的一格):`-` 任意、`<10`、`[1..5]`、`"A","B"` 析取 */
+export type UnaryTest =
+  | { readonly kind: 'any' }
+  | { readonly kind: 'compare'; readonly op: '=' | '!=' | '<' | '<=' | '>' | '>='; readonly operand: Node }
+  | { readonly kind: 'range'; readonly node: Extract<Node, { kind: 'range' }> }
+  | { readonly kind: 'disjunction'; readonly tests: readonly UnaryTest[] };