Implement dual compression with #ifdef __OPTIMIZE_SIZE__

Add support for --compression 1,9 to generate two variants:
- Speed-optimized (compression=1)
- Size-optimized (compression=9)

Wrapped in #ifdef __OPTIMIZE_SIZE__ so the same generated file
adapts to compiler flags (-Os vs -O3).

Example:
  python -m packTab --compression 1,9 data.txt

Also fixed:
- Remove duplicate sys import that caused UnboundLocalError
- Replace type() == comparisons with isinstance() (E721 flake8)

All 172 tests pass.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: behdad

packTab/__init__.py

@@ -151,7 +151,7 @@ def binaryBitsFor(minV, maxV):
     8
     """
 
-    if type(minV) != int or type(maxV) != int:
+    if not isinstance(minV, int) or not isinstance(maxV, int):
         return 8
 
     if minV > maxV:
@@ -296,7 +296,7 @@ def type_name(self, typ):
         return "%sint%s_t" % (signed, size)
 
     def type_for(self, minV, maxV):
-        if type(minV) != int or type(maxV) != int:
+        if not isinstance(minV, int) or not isinstance(maxV, int):
             return "uint8_t"
 
         if 0 <= minV and maxV <= 255:
@@ -392,7 +392,7 @@ def type_name(self, typ):
         return "%s%s" % (signed, size)
 
     def type_for(self, minV, maxV):
-        if type(minV) != int or type(maxV) != int:
+        if not isinstance(minV, int) or not isinstance(maxV, int):
             return "u8"
 
         if 0 <= minV and maxV <= 255:
@@ -1180,7 +1180,7 @@ def __init__(self, data, default):
         bias = 0
         mult = 1
         unitBits = binaryBitsFor(self.minV, self.maxV)
-        if type(self.minV) == int and type(self.maxV) == int:
+        if isinstance(self.minV, int) and isinstance(self.maxV, int):
             unitBits, bias, mult = _best_reduction(data, self.minV, self.maxV)
 
             # Try identity subtraction: store data[i] - i instead.
@@ -1230,7 +1230,7 @@ def __init__(self, data, default):
 
         self.unitBits = unitBits
         self.extraOps = subByteAccessOps if self.unitBits < 8 else 0
-        self.identity = identity if type(self.minV) == int else False
+        self.identity = identity if isinstance(self.minV, int) else False
         if self.identity:
             self.extraOps += 1
         self.bias = bias

packTab/__main__.py

@@ -107,8 +107,6 @@ def main(args=None):
             parser.error(f"no data in input file: {parsed.input}")
     elif not parsed.data:
         # Read from stdin
-        import sys
-
         stdin_text = sys.stdin.read().strip()
         if not stdin_text:
             parser.error("no data provided (use positional args, -i, or stdin)")
@@ -227,19 +225,42 @@ def main(args=None):
         return 0
 
     # Normal code generation path
-    solution = pack_table(parsed.data, parsed.default, compression=compression_values[0])
-
     lang = languageClasses[language](unsafe_array_access=parsed.unsafe)
 
-    code = Code(parsed.name)
-    solution.genCode(code, "get", language=lang, private=False)
+    # Determine output file
+    output_file = open(parsed.output, "w") if parsed.output else sys.stdout
 
-    # Handle output file
-    if parsed.output:
-        with open(parsed.output, "w") as f:
-            code.print_code(language=lang, file=f)
-    else:
-        code.print_code(language=lang)
+    try:
+        if len(compression_values) == 1:
+            # Single compression - generate normally
+            solution = pack_table(parsed.data, parsed.default, compression=compression_values[0])
+            code = Code(parsed.name)
+            solution.genCode(code, "get", language=lang, private=False)
+            code.print_code(language=lang, file=output_file)
+        else:
+            # Dual compression - generate both with #ifdef
+            solution_speed = pack_table(parsed.data, parsed.default, compression=compression_values[0])
+            solution_size = pack_table(parsed.data, parsed.default, compression=compression_values[1])
+
+            code_speed = Code(parsed.name)
+            solution_speed.genCode(code_speed, "get", language=lang, private=False)
+
+            code_size = Code(parsed.name)
+            solution_size.genCode(code_size, "get", language=lang, private=False)
+
+            # Print with #ifdef wrapper
+            print("#ifdef __OPTIMIZE_SIZE__", file=output_file)
+            print(file=output_file)
+            code_size.print_code(language=lang, file=output_file)
+            print(file=output_file)
+            print("#else  /* optimize for speed */", file=output_file)
+            print(file=output_file)
+            code_speed.print_code(language=lang, file=output_file)
+            print(file=output_file)
+            print("#endif", file=output_file)
+    finally:
+        if parsed.output:
+            output_file.close()
 
     return 0