eapi: add Eapi.parse() support

src/pkgcraft/C.pxd

@@ -1110,6 +1110,14 @@ cdef extern from "pkgcraft.h":
     # The argument must be a non-null Eapi pointer.
     char **pkgcraft_eapi_metadata_keys(const Eapi *eapi, uintptr_t *len)
 
+    # Determine if a string is a valid EAPI.
+    #
+    # Returns NULL on error.
+    #
+    # # Safety
+    # The argument should point to a UTF-8 string.
+    const char *pkgcraft_eapi_parse(const char *s)
+
     # Get all known EAPIS.
     #
     # # Safety

src/pkgcraft/dep/version.pyx

@@ -146,7 +146,7 @@ cdef class Version:
     def parse(s: str, raised=False):
         """Determine if a string is a valid package version.
 
-        This avoids any allocations, only returning the validity status.
+        This avoids any string allocations, only returning the validity status.
 
         Args:
             s: the string to parse

src/pkgcraft/eapi.pyx

@@ -113,6 +113,33 @@ cdef class Eapi(Indirect):
         """Try to convert an object to an Eapi object."""
         return Eapi._from_obj(obj)
 
+    @staticmethod
+    def parse(s: str, raised=False):
+        """Determine if a string is a valid EAPI.
+
+        This avoids any string allocations, only returning the validity status.
+
+        Args:
+            s: the string to parse
+            raised: if True, raise an exception when invalid
+
+        Returns:
+            bool: True if the given string represents a valid EAPI, otherwise False.
+
+        Raises:
+            PkgcraftError: on failure if the raised parameter is set to True
+
+        >>> from pkgcraft.eapi import Eapi
+        >>> Eapi.parse('01')
+        True
+        >>> Eapi.parse('@1')
+        False
+        """
+        valid = C.pkgcraft_eapi_parse(s.encode()) is not NULL
+        if not valid and raised:
+            raise PkgcraftError
+        return valid
+
     def has(self, s: str):
         """Check if an EAPI has a given feature.
 

tests/test_eapi.py

@@ -3,6 +3,7 @@
 import pytest
 
 from pkgcraft.eapi import *
+from pkgcraft.error import PkgcraftError
 
 from .misc import OperatorMap
 
@@ -22,6 +23,13 @@ def test_globals():
 
 
 class TestEapi:
+    def test_parse(self):
+        assert Eapi.parse("01")
+        for s in ("@1", "-1", ".1"):
+            assert not Eapi.parse(s)
+            with pytest.raises(PkgcraftError, match=f"invalid EAPI: {s}"):
+                Eapi.parse(s, raised=True)
+
     def test_has(self):
         assert not EAPI_LATEST_OFFICIAL.has("RepoIds")
         assert EAPI_LATEST.has("RepoIds")