[210_12] feat(srfi-19): 初始化 time 和 date 结构，实现部分函数

devel/210_12.md

@@ -0,0 +1,33 @@
+# [210_12] `(srfi srfi-19)`
+
+## 任务相关的代码文件
+- `src/goldfish.hpp`
+- `tests/goldfish/liii/time-test.scm`
+- `goldfish/scheme/time.scm`
+- `goldfish/srfi/srfi-19.scm`
+
+## 如何测试
+
+```shell
+# 可能需要清除缓存
+# rm .xmake/ build/ -r
+xmake f -vyD
+xmake b goldfish
+./bin/goldfish tests/goldfish/liii/time-test.scm
+```
+
+## 2026/1/30 初始化 time 和 date 结构
+
+### What
+
+1. 新增 glue：`g_get-time-of-day`, `g_monotonic-nanosecond`, `g_steady-clock-resolution`, `g_system-clock-resolution`
+2. 实现 time 与 date 基本结构
+3. 实现部分 SRFI-19 proc，包括 `current-time`, `date->string` 等
+
+### Why
+
+扩充时间与日期的支持。
+
+### How
+
+通过 C++17 的 chrono 绑定实现。

goldfish/scheme/time.scm

@@ -15,15 +15,26 @@
 ;
 
 (define-library (scheme time)
-  (export current-second current-jiffy jiffies-per-second)
+  (import (only (scheme base) let-values s7-round))
+  (export current-second current-jiffy jiffies-per-second
+          get-time-of-day monotonic-nanosecond
+          system-clock-resolution steady-clock-resolution)
   (begin
 
     (define (jiffies-per-second) 1000000)
 
-    (define (current-second) (g_current-second))
+    (define get-time-of-day g_get-time-of-day)
+    (define monotonic-nanosecond g_monotonic-nanosecond)
+    (define system-clock-resolution g_system-clock-resolution)
+    (define steady-clock-resolution g_steady-clock-resolution)
+
+    (define (current-second)
+      (let-values (((sec usec) (get-time-of-day)))
+        (+ sec (exact->inexact (/ usec 1000000)))))
 
     (define (current-jiffy)
-      (round (* (current-second) (jiffies-per-second))))
+      ;; NOTE: use the s7-round to ensure that a natural number is returned.
+      (s7-round (* (current-second) (jiffies-per-second))))
 
     ) ; end of begin
   ) ; end of define-library