greek_stemmer.rb in greek_stemmer-1.1.4

- old
+ new
@@ -70,10 +70,16 @@
     stem.scan(/^(.+?)(ΕΩΣ|ΕΩΝ|ΕΑΣ|ΕΑ)$/u) do |st, suffix|
       stem = st
       stem << "Ε" if st =~ /^(Θ|Δ|ΕΛ|ΓΑΛ|Ν|Π|ΙΔ|ΠΑΡ|ΣΤΕΡ|ΟΡΦ|ΑΝΔΡ|ΑΝΤΡ)$/u
     end
 
-    # step 3
+    # step 3a
+    stem.scan(/^(.+?)(ΕΙΟ|ΕΙΟΣ|ΕΙΟΙ|ΕΙΑ|ΕΙΑΣ|ΕΙΕΣ|ΕΙΟΥ|ΕΙΟΥΣ|ΕΙΩΝ)$/u) do |st, suffix|
+      # be conservative with this rule, take care for overstemming.
+      stem = st if st.length > 4
+    end
+
+    # step 3b
     stem.scan(/^(.+?)(ΙΟΥΣ|ΙΑΣ|ΙΕΣ|ΙΟΣ|ΙΟΥ|ΙΟΙ|ΙΩΝ|ΙΟΝ|ΙΑ|ΙΟ)$/u) do |st, suffix|
       stem  = st
       stem << "Ι" if ends_on_vowel?(st) || st.length < 2 || st=~ /^(ΑΓ|ΑΓΓΕΛ|ΑΓΡ|
                      ΑΕΡ|ΑΘΛ|ΑΚΟΥΣ|ΑΞ|ΑΣ|Β|ΒΙΒΛ|ΒΥΤ|Γ|ΓΙΑΓ|ΓΩΝ|Δ|ΔΑΝ|ΔΗΛ|ΔΗΜ|
                      ΔΟΚΙΜ|ΕΛ|ΖΑΧΑΡ|ΗΛ|ΗΠ|ΙΔ|ΙΣΚ|ΙΣΤ|ΙΟΝ|ΙΩΝ|ΚΙΜΩΛ|ΚΟΛΟΝ|ΚΟΡ|