1 files changed, 67 insertions, 0 deletions
diff --git a/lib/spack/llnl/string.py b/lib/spack/llnl/string.py
new file mode 100644
index 0000000000..a203be8d34
--- /dev/null
+++ b/lib/spack/llnl/string.py
@@ -0,0 +1,67 @@
+# Copyright 2013-2023 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+"""String manipulation functions that do not have other dependencies than Python
+standard library
+"""
+from typing import List, Optional
+
+
+def comma_list(sequence: List[str], article: str = "") -> str:
+    if type(sequence) is not list:
+        sequence = list(sequence)
+
+    if not sequence:
+        return ""
+    if len(sequence) == 1:
+        return sequence[0]
+
+    out = ", ".join(str(s) for s in sequence[:-1])
+    if len(sequence) != 2:
+        out += ","  # oxford comma
+    out += " "
+    if article:
+        out += article + " "
+    out += str(sequence[-1])
+    return out
+
+
+def comma_or(sequence: List[str]) -> str:
+    """Return a string with all the elements of the input joined by comma, but the last
+    one (which is joined by 'or').
+    """
+    return comma_list(sequence, "or")
+
+
+def comma_and(sequence: List[str]) -> str:
+    """Return a string with all the elements of the input joined by comma, but the last
+    one (which is joined by 'and').
+    """
+    return comma_list(sequence, "and")
+
+
+def quote(sequence: List[str], q: str = "'") -> List[str]:
+    """Quotes each item in the input list with the quote character passed as second argument."""
+    return [f"{q}{e}{q}" for e in sequence]
+
+
+def plural(n: int, singular: str, plural: Optional[str] = None, show_n: bool = True) -> str:
+    """Pluralize <singular> word by adding an s if n != 1.
+
+    Arguments:
+        n: number of things there are
+        singular: singular form of word
+        plural: optional plural form, for when it's not just singular + 's'
+        show_n: whether to include n in the result string (default True)
+
+    Returns:
+        "1 thing" if n == 1 or "n things" if n != 1
+    """
+    number = f"{n} " if show_n else ""
+    if n == 1:
+        return f"{number}{singular}"
+    elif plural is not None:
+        return f"{number}{plural}"
+    else:
+        return f"{number}{singular}s"