feat(inner): Python/config_read_env

Author: litlighilit

src/pylib/Python/config_read_env.nim

@@ -0,0 +1,25 @@
+
+
+import std/os
+import std/strutils
+
+using name: string
+func toAllUpper(name): string {.inline.} =
+  for c in name:
+    case c
+    of 'a'..'z': result.add chr(ord(c) or 0b100000)
+    else: discard # '_' is discarded, so for other chars
+func toPyEnv*(name): string {.inline.} = "PYTHON" & name.toAllUpper
+proc ib_i*[T](name; flagInit: T): T =
+  let v = getEnv(name)
+  if v.len == 0: return
+  max(flagInit, T(
+    try:
+      let val = parseInt(v)
+      if val < 0: 1 # PYTHONDEBUG=text and PYTHONDEBUG=-2 behave as PYTHONDEBUG=1
+      else: val
+    except ValueError: 1
+  ))
+proc ib_e*[T](name; flagInit: T): T = flagInit or T existsEnv name
+proc ib_b*(name; flagInit: int): int = min 1, ib_i(name, flagInit)
+proc ib_b*(name; flagInit: bool): bool = ib_i(name, flagInit)