Initial data commit

Task/Simple-database/Wren/simple-database-2.wren

@@ -0,0 +1,68 @@
+import "os" for Process
+import "./table" for Table, FieldInfo, File
+import "./str" for Str
+
+var printUsage = Fn.new {
+    System.print("""
+Usage:
+  wren simdb.wren cmd [categoryName]
+  add     add item name and date, followed by optional category
+  latest  print item with latest date, followed by optional category
+  all     print all
+  For instance: add "some item name", "some item date", "some category name"
+  Dates should be in format: yyyy-mm-dd
+""")
+}
+
+var printLatest = Fn.new { |table, a|
+    if (table.isEmpty) {
+        System.print("No entries in table.")
+        return
+    }
+    var records = table.records
+    records.sort { |s, t| Str.lt(s[1], t[1]) }  // sort by ascending date
+    if (a.count == 1) {
+        var found = false
+        for (record in records[-1..0]) {
+            if (record[2] == a[0]) {
+                System.print(record)
+                found = true
+                break
+            }
+        }
+        if (!found) System.print("There are no records for category '%(a[0])'.")
+    } else System.print(records[-1])
+}
+
+var args = Process.arguments
+if (!(1..4).contains(args.count)) {
+    printUsage.call()
+    return
+}
+
+// create a new Table object
+var tableName = "simdb"
+var table
+if (Table.fileExists(tableName)) {
+    table = Table.load(tableName)
+} else {
+    var fis = [
+        FieldInfo.new("name", String),
+        FieldInfo.new("date", String),
+        FieldInfo.new("category", String)
+    ]
+    table = Table.new(tableName, fis)
+}
+
+var cmd = Str.lower(args[0])
+if (cmd == "add") {
+    if (args.count < 4) args.add("none")
+    table.add(args[1..-1])
+    table.save()
+} else if (cmd == "latest") {
+    printLatest.call(table, args[1..-1])
+} else if (cmd == "all") {
+    table.list()
+} else {
+    printUsage.call()
+}