Added some CLI args support. (0.37.35)

lib/cli.fun

@@ -0,0 +1,53 @@
+// Simple CLI helpers for Fun scripts.
+//
+// argv(): returns an array of the raw arguments passed to the script
+//         (not including the script path). Requires the interpreter to
+//         export FUN_ARGC and FUN_ARGV_i environment variables.
+// parse_args(args): parses flags and positionals from argv() like:
+//   -f  -> flags["f"] = 1
+//   --force -> flags["force"] = 1
+//   --force=42 -> flags["force"] = "42"
+//   -abc -> flags["a"]=1, flags["b"]=1, flags["c"]=1
+
+fun argv()
+  n = to_number(env("FUN_ARGC"))
+  a = []
+  i = 0
+  while (i < n)
+    key = join(["FUN_ARGV_", to_string(i)], "")
+    push(a, env(key))
+    i = i + 1
+  return a
+
+// Returns: { "flags": map, "positionals": array }
+fun parse_args(args)
+  flags = {}
+  pos = []
+  i = 0
+  n = len(args)
+  while (i < n)
+    s = args[i]
+    if (len(s) >= 2 && substr(s, 0, 2) == "--")
+      eq = find(s, "=")
+      if (eq >= 0)
+        key = substr(s, 2, eq - 2)           // between -- and =
+        val = substr(s, eq + 1, len(s) - (eq + 1))
+        flags[key] = val
+      else
+        key = substr(s, 2, len(s) - 2)
+        flags[key] = 1
+    else if (len(s) == 2 && substr(s, 0, 1) == "-")
+      // short -f boolean
+      key = substr(s, 1, 1)
+      flags[key] = 1
+    else if (len(s) > 2 && substr(s, 0, 1) == "-")
+      // compact short flags like -abc -> a=1, b=1, c=1
+      j = 1
+      while (j < len(s))
+        k = substr(s, j, 1)
+        flags[k] = 1
+        j = j + 1
+    else
+      push(pos, s)
+    i = i + 1
+  return { "flags": flags, "positionals": pos }