Je was op zoek naar: quantifiers (Engels - Kinyarwanda)

denotes numeric quantifiers.
bikurikije umubare.

here are a few examples of using quantifiers
a ingero bya ikoresha

quantifiers allows a regular expression to match a specified number or range of numbers of either a character, character class or sub pattern.
a ibisanzwe imvugo kuri bihuye a umubare cyangwa urutonde bya imibare bya a inyuguti:, inyuguti: urwego: cyangwa ishusho.

when using quantifiers with no maximum, regular expressions defaults to match as much of the searched string as possible, commonly known as greedy behavior.
ikoresha na: oya kinini, ibisanzwe mburabuzi kuri bihuye nka bya i ikurikiranyanyuguti nka, nka & imyifatire.

the following sections will describe in details how to construct and use patterns, character classes, assertions, quantifiers and back references, and the final section will give a few useful examples.
ibyatoranyijwe in birambuye kuri na koresha imitako, inyuguti: inzego,, na inyuma indango, na i bihera icyiciro a ingero.

an optional character. can be interpreted as a quantifier, 0 or 1.
bitari ngombwa inyuguti:. nka a, 0% s cyangwa 1.