SML × Government Data Exchange { ❄ }

Government data has three chronic pain points — SML addresses each one:

Pain point	Consequence	SML answer
18-digit ID / credit codes parsed as numbers	JSON floats eat precision: `330106201503071234` → `...071200`	Identifiers are strings, preserved verbatim
Misspelled fields pass silently	`prot` and `port` coexist in one config	`strict` contract rejects on the spot
Copy-pasted per-department configs	Fix one place, miss five	`@base` fragment: define once, expand everywhere

Below is a district-level “government service item” exchange file — two window blocks share one strict contract and one locale fragment. Run it, or break it as the task suggests, and watch the contract intercept:

✍ Hands-on exercise Add a third window: 城管窗口 (名称=门头招牌备案, 承诺时限=10, 电话="0571-87654323", reuse locale info via &base), and change 公安窗口密级 to 内部.

💡 Hint: Set 密级 to 内部涉密 (not in the enum whitelist) or 承诺时限 to 91 (over max 90) to watch the contract intercept.

// ── 区政务数据交换 · 示范文件 ──

@contract 事项 strict {
  名称: str
  部门: str
  承诺时限: int min 1 max 90
  密级: enum [ 公开 内部 秘密 机密 绝密 ] default 公开
  电话: str
  // 片段展开的字段也要在契约中声明 —— 契约面必须完整
  办理地点: str
  区划代码: str
}

// 各部门共享的属地信息：一处定义，处处展开
@base {
  办理地点: 区行政服务中心
  区划代码: "330106"
}

公安窗口 {
  @is 事项
  名称: 居住证办理
  部门: 公安分局
  承诺时限: 7
  电话: "0571-87654321"
  &base
}

人社窗口 {
  @is 事项
  名称: 社保卡申领
  部门: 人社局
  承诺时限: 5
  密级: 内部
  电话: "0571-87654322"
  &base
}

Both engines (JS preview / Rust wasm faithful) run the same contract validation with identical verdicts.