interpreter: Add hex/octal/binary support to str and int primitives

Add support for parsing and formatting integers in hexadecimal, octal,
and binary representations to complement the existing decimal support.

str.to_int() now accepts strings with 0x/0o/0b prefixes and optional
leading signs (+/-), enabling direct parsing of hex, octal, and binary
literals while maintaining full backward compatibility with decimal
strings including those with leading zeros.

int.to_string() gains a new format keyword argument that accepts 'dec',
'hex', 'oct', or 'bin', allowing integers to be formatted with
appropriate prefixes (0x, 0o, 0b). The format parameter works correctly
with the existing fill parameter and handles negative numbers properly.

Round-trip conversions are fully supported: values formatted with
int.to_string(format: 'hex') can be parsed back with str.to_int().

Fixes: #2047
Fixes: #15201

Author: cdown

docs/markdown/Syntax.md

@@ -80,13 +80,31 @@ string_var = '42'
 num = string_var.to_int()
 ```
 
+Hexadecimal, octal, and binary strings can be converted to numbers since
+1.10.0:
+
+```meson
+hex_var = '0xFF'.to_int()    # 255
+oct_var = '0o755'.to_int()   # 493
+bin_var = '0b1010'.to_int()  # 10
+```
+
 Numbers can be converted to a string:
 
 ```meson
 int_var = 42
 string_var = int_var.to_string()
 ```
 
+Numbers can be formatted as hexadecimal, octal, or binary strings since 1.10.0:
+
+```meson
+int_var = 255
+hex_str = int_var.to_string(format: 'hex')  # '0xff'
+oct_str = int_var.to_string(format: 'oct')  # '0o377'
+bin_str = int_var.to_string(format: 'bin')  # '0b11111111'
+```
+
 ## Booleans
 
 A boolean is either `true` or `false`.

mesonbuild/interpreter/primitives/integer.py

@@ -7,12 +7,20 @@
     FeatureBroken, InvalidArguments, KwargInfo,
     noKwargs, noPosargs, typed_operator, typed_kwargs
 )
+from ..type_checking import in_set_validator
 
 import typing as T
 
 if T.TYPE_CHECKING:
+    from typing_extensions import Literal, TypedDict
+
     from ...interpreterbase import TYPE_var, TYPE_kwargs
 
+    class ToStringKw(TypedDict):
+
+        fill: int
+        format: Literal["dec", "hex", "oct", "bin"]
+
 class IntegerHolder(ObjectHolder[int]):
     # Operators that only require type checks
     TRIVIAL_OPERATORS = {
@@ -55,12 +63,20 @@ def is_odd_method(self, args: T.List[TYPE_var], kwargs: TYPE_kwargs) -> bool:
 
     @typed_kwargs(
         'to_string',
-        KwargInfo('fill', int, default=0, since='1.3.0')
+        KwargInfo('fill', int, default=0, since='1.3.0'),
+        KwargInfo(
+            "format",
+            str,
+            default="dec",
+            since="1.10.0",
+            validator=in_set_validator({"dec", "hex", "oct", "bin"}),
+        ),
     )
     @noPosargs
     @InterpreterObject.method('to_string')
-    def to_string_method(self, args: T.List[TYPE_var], kwargs: T.Dict[str, T.Any]) -> str:
-        return str(self.held_object).zfill(kwargs['fill'])
+    def to_string_method(self, args: T.List[TYPE_var], kwargs: 'ToStringKw') -> str:
+        format_codes = {"hex": "x", "oct": "o", "bin": "b", "dec": "d"}
+        return format(self.held_object, f'#0{kwargs["fill"]}{format_codes[kwargs["format"]]}')
 
     @typed_operator(MesonOperator.DIV, int)
     @InterpreterObject.operator(MesonOperator.DIV)

mesonbuild/interpreter/primitives/string.py

@@ -132,7 +132,19 @@ def substring_method(self, args: T.Tuple[T.Optional[int], T.Optional[int]], kwar
     @InterpreterObject.method('to_int')
     def to_int_method(self, args: T.List[TYPE_var], kwargs: TYPE_kwargs) -> int:
         try:
-            return int(self.held_object)
+            s = self.held_object.strip()
+            s_unsigned = s.lstrip('+-').lower()
+
+            if s_unsigned.startswith('0x'):
+                base = 16
+            elif s_unsigned.startswith('0o'):
+                base = 8
+            elif s_unsigned.startswith('0b'):
+                base = 2
+            else:
+                base = 10
+
+            return int(s, base)
         except ValueError:
             raise InvalidArguments(f'String {self.held_object!r} cannot be converted to int')
 

test cases/common/286 number base conversions/meson.build

@@ -0,0 +1,131 @@
+project('test number base conversions')
+
+### .to_int()
+
+# hexadecimal strings
+assert('0x10'.to_int() == 16, 'Hex string conversion failed')
+assert('0X10'.to_int() == 16, 'Hex string conversion (uppercase X) failed')
+assert('0xff'.to_int() == 255, 'Hex string conversion (lowercase) failed')
+assert('0xFF'.to_int() == 255, 'Hex string conversion (uppercase) failed')
+assert('0xDEADBEEF'.to_int() == 3735928559, 'Large hex conversion failed')
+assert('0x1'.to_int() == 1, 'Small hex conversion failed')
+assert('0x0'.to_int() == 0, 'Zero hex conversion failed')
+
+# signed hexadecimal strings
+assert('-0xf'.to_int() == -15, 'Negative hex string conversion failed')
+assert('+0x10'.to_int() == 16, 'Positive hex string conversion failed')
+assert('-0xFF'.to_int() == -255, 'Negative hex string (uppercase) conversion failed')
+
+# octal strings
+assert('0o10'.to_int() == 8, 'Octal string conversion failed')
+assert('0O10'.to_int() == 8, 'Octal string conversion (uppercase O) failed')
+assert('0o77'.to_int() == 63, 'Octal string conversion failed')
+assert('0o755'.to_int() == 493, 'Octal permission-like conversion failed')
+assert('0o0'.to_int() == 0, 'Zero octal conversion failed')
+
+# signed octal strings
+assert('-0o10'.to_int() == -8, 'Negative octal string conversion failed')
+assert('+0o77'.to_int() == 63, 'Positive octal string conversion failed')
+
+# binary strings
+assert('0b10'.to_int() == 2, 'Binary string conversion failed')
+assert('0B10'.to_int() == 2, 'Binary string conversion (uppercase B) failed')
+assert('0b1111'.to_int() == 15, 'Binary string conversion failed')
+assert('0b11111111'.to_int() == 255, 'Binary byte conversion failed')
+assert('0b0'.to_int() == 0, 'Zero binary conversion failed')
+
+# signed binary strings
+assert('-0b101'.to_int() == -5, 'Negative binary string conversion failed')
+assert('+0b1111'.to_int() == 15, 'Positive binary string conversion failed')
+
+# decimal strings (backwards compat)
+assert('10'.to_int() == 10, 'Decimal string conversion failed')
+assert('255'.to_int() == 255, 'Decimal string conversion failed')
+assert('0'.to_int() == 0, 'Zero decimal conversion failed')
+assert('12345'.to_int() == 12345, 'Large decimal conversion failed')
+
+# leading zeroes are decimal (backwards compat)
+assert('010'.to_int() == 10, 'Decimal with leading zero broke backward compatibility')
+assert('0123'.to_int() == 123, 'Decimal with leading zeros broke backward compatibility')
+assert('007'.to_int() == 7, 'Decimal with leading zeros broke backward compatibility')
+
+### .to_string()
+
+# hex format
+assert(16.to_string(format: 'hex') == '0x10', 'Int to hex string failed')
+assert(255.to_string(format: 'hex') == '0xff', 'Int to hex string failed')
+assert(0.to_string(format: 'hex') == '0x0', 'Zero to hex string failed')
+assert(1.to_string(format: 'hex') == '0x1', 'One to hex string failed')
+assert(3735928559.to_string(format: 'hex') == '0xdeadbeef', 'Large hex string failed')
+
+# octal format
+assert(8.to_string(format: 'oct') == '0o10', 'Int to octal string failed')
+assert(63.to_string(format: 'oct') == '0o77', 'Int to octal string failed')
+assert(493.to_string(format: 'oct') == '0o755', 'Permission to octal string failed')
+assert(0.to_string(format: 'oct') == '0o0', 'Zero to octal string failed')
+
+# binary format
+assert(2.to_string(format: 'bin') == '0b10', 'Int to binary string failed')
+assert(15.to_string(format: 'bin') == '0b1111', 'Int to binary string failed')
+assert(255.to_string(format: 'bin') == '0b11111111', 'Byte to binary string failed')
+assert(0.to_string(format: 'bin') == '0b0', 'Zero to binary string failed')
+
+# decimal format (explicit)
+assert(10.to_string(format: 'dec') == '10', 'Int to decimal string failed')
+assert(255.to_string(format: 'dec') == '255', 'Int to decimal string failed')
+
+# default
+assert(42.to_string() == '42', 'Default int to string failed')
+
+# fill and hex format
+assert(255.to_string(format: 'hex', fill: 8) == '0x0000ff', 'Hex with fill failed')
+assert(1.to_string(format: 'hex', fill: 6) == '0x0001', 'Hex with fill failed')
+assert(255.to_string(format: 'hex', fill: 4) == '0xff', 'Hex with fill (no padding needed) failed')
+
+# fill and other formats
+assert(8.to_string(format: 'oct', fill: 6) == '0o0010', 'Octal with fill failed')
+assert(2.to_string(format: 'bin', fill: 10) == '0b00000010', 'Binary with fill failed')
+
+# negative numbers
+assert((-15).to_string(format: 'hex') == '-0xf', 'Negative hex conversion failed')
+assert((-8).to_string(format: 'oct') == '-0o10', 'Negative octal conversion failed')
+assert((-5).to_string(format: 'bin') == '-0b101', 'Negative binary conversion failed')
+
+# negative numbers and fill
+assert((-15).to_string(format: 'hex', fill: 6) == '-0x00f', 'Negative hex with fill failed')
+assert((-8).to_string(format: 'oct', fill: 7) == '-0o0010', 'Negative octal with fill failed')
+assert((-5).to_string(format: 'bin', fill: 8) == '-0b00101', 'Negative binary with fill failed')
+assert((-4).to_string(fill: 3) == '-04', 'Negative decimal with fill failed')
+
+# fill and decimal
+assert(4.to_string(fill: 3) == '004', 'Decimal with fill failed')
+
+### Round trip conversions
+
+# positive
+
+hex_val = 0x200
+hex_str = hex_val.to_string(format: 'hex')
+assert(hex_str.to_int() == hex_val, 'Hex round-trip failed')
+
+oct_val = 0o755
+oct_str = oct_val.to_string(format: 'oct')
+assert(oct_str.to_int() == oct_val, 'Octal round-trip failed')
+
+bin_val = 0b11010
+bin_str = bin_val.to_string(format: 'bin')
+assert(bin_str.to_int() == bin_val, 'Binary round-trip failed')
+
+# negative
+
+neg_hex = -255
+neg_hex_str = neg_hex.to_string(format: 'hex')
+assert(neg_hex_str.to_int() == neg_hex, 'Negative hex round-trip failed')
+
+neg_oct = -63
+neg_oct_str = neg_oct.to_string(format: 'oct')
+assert(neg_oct_str.to_int() == neg_oct, 'Negative octal round-trip failed')
+
+neg_bin = -15
+neg_bin_str = neg_bin.to_string(format: 'bin')
+assert(neg_bin_str.to_int() == neg_bin, 'Negative binary round-trip failed')

test cases/common/35 string operations/meson.build

@@ -54,6 +54,9 @@ assert('#include <foo/bar.h>'.underscorify() == '_include__foo_bar_h_', 'Broken
 assert('Do SomeThing 09'.underscorify() == 'Do_SomeThing_09', 'Broken underscorify')
 
 assert('3'.to_int() == 3, 'String int conversion does not work.')
+assert('0x10'.to_int() == 16, 'Hex string conversion does not work.')
+assert('0o10'.to_int() == 8, 'Octal string conversion does not work.')
+assert('0b10'.to_int() == 2, 'Binary string conversion does not work.')
 
 assert(true.to_string() == 'true', 'bool string conversion failed')
 assert(false.to_string() == 'false', 'bool string conversion failed')