refactor: extract IO class into separate module with wrenLoadIOLibrary and wren_io.c

Replace monolithic corelib.wren with per-class builtin/*.wren files and generate_builtins.py script. Move IO class definition and its native writeString_ method from wren_core.c to new wren_io.c, adding wrenGetArgumentString and wrenDefineStaticMethod to the public API. Update Makefile target from corelib to builtin and remove generate_corelib.py.

script/generate_builtins.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+import glob
+import os.path
+import re
+
+PATTERN = re.compile(r'libSource =\n("(.|[\n])*?);')
+
+def copy_builtin(filename):
+  name = os.path.basename(filename)
+  name = name.split('.')[0]
+
+  with open(filename, "r") as f:
+    lines = f.readlines()
+
+  wren_source = ""
+  for line in lines:
+    line = line.replace('"', "\\\"")
+    line = line.replace("\n", "\\n\"")
+    if wren_source: wren_source += "\n"
+    wren_source += '"' + line
+
+  # re.sub() will unescape escape sequences, but we want them to stay escapes
+  # in the C string literal.
+  wren_source = wren_source.replace('\\', '\\\\')
+
+  constant = "libSource =\n" + wren_source + ";"
+
+  with open("src/wren_" + name + ".c", "r") as f:
+    c_source = f.read()
+
+  c_source = PATTERN.sub(constant, c_source)
+
+  with open("src/wren_" + name + ".c", "w") as f:
+    f.write(c_source)
+
+  print name
+
+
+for f in glob.iglob("builtin/*.wren"):
+  copy_builtin(f)

script/generate_corelib.py

@@ -1,31 +0,0 @@
-#!/usr/bin/env python
-import re
-
-with open("corelib.wren", "r") as f:
-  lines = f.readlines()
-
-# Remove the comment from the top.
-lines.pop(0)
-lines.pop(0)
-
-corelib = ""
-for line in lines:
-  line = line.replace('"', "\\\"")
-  line = line.replace("\n", "\\n\"")
-  if corelib: corelib += "\n"
-  corelib += '"' + line
-
-with open("src/wren_core.c", "r") as f:
-  wren_core = f.read()
-
-# re.sub() will unescape escape sequences, but we want them to stay as escapes
-# in the C string literal.
-corelib = corelib.replace('\\', '\\\\')
-
-corelib = "coreLibSource =\n" + corelib + ";"
-
-PATTERN = re.compile(r'coreLibSource =\n("(.|[\n])*?);')
-wren_core = PATTERN.sub(corelib, wren_core)
-
-with open("src/wren_core.c", "w") as f:
-  f.write(wren_core)