Add range() function

Fixes: #5026.

1 files changed, 24 insertions, 2 deletions

diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index d554cce..364cf70 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -30,7 +30,7 @@ from .interpreterbase import check_stringlist, flatten, noPosargs, noKwargs, str
 from .interpreterbase import InterpreterException, InvalidArguments, InvalidCode, SubdirDoneRequest
 from .interpreterbase import InterpreterObject, MutableInterpreterObject, Disabler, disablerIfNotFound
 from .interpreterbase import FeatureNew, FeatureDeprecated, FeatureNewKwargs, FeatureDeprecatedKwargs
-from .interpreterbase import ObjectHolder, MesonVersionString
+from .interpreterbase import ObjectHolder, MesonVersionString, RangeHolder
 from .interpreterbase import TYPE_var, TYPE_nkwargs
 from .modules import ModuleReturnValue, ModuleObject, ModuleState
 from .cmake import CMakeInterpreter
@@ -2509,7 +2509,8 @@ class Interpreter(InterpreterBase):
                            'static_library': self.func_static_lib,
                            'both_libraries': self.func_both_lib,
                            'test': self.func_test,
-                           'vcs_tag': self.func_vcs_tag
+                           'vcs_tag': self.func_vcs_tag,
+                           'range': self.func_range,
                            })
         if 'MESON_UNIT_TEST' in os.environ:
             self.funcs.update({'exception': self.func_exception})
@@ -5033,3 +5034,24 @@ This will become a hard error in the future.''', location=self.current_node)
             raise InvalidCode('Is_disabler takes one argument.')
         varname = args[0]
         return isinstance(varname, Disabler)
+
+    @noKwargs
+    @FeatureNew('range', '0.58.0')
+    @typed_pos_args('range', int, optargs=[int, int])
+    def func_range(self, node, args: T.Tuple[int, T.Optional[int], T.Optional[int]], kwargs: T.Dict[str, T.Any]) -> RangeHolder:
+        start, stop, step = args
+        # Just like Python's range, we allow range(stop), range(start, stop), or
+        # range(start, stop, step)
+        if stop is None:
+            stop = start
+            start = 0
+        if step is None:
+            step = 1
+        # This is more strict than Python's range()
+        if start < 0:
+            raise InterpreterException('start cannot be negative')
+        if stop < start:
+            raise InterpreterException('stop cannot be less than start')
+        if step < 1:
+            raise InterpreterException('step must be >=1')
+        return RangeHolder(start, stop, step)