From 05e009b90626d989349e9cf60e2af45aac4a4ffe Mon Sep 17 00:00:00 2001
From: Peng Wu <alexepico@gmail.com>
Date: Thu, 19 Jan 2017 17:20:13 +0800
Subject: write trellis_value_less_than function

---
 src/lookup/phonetic_lookup.h        | 22 ++++++++++++++++++++++
 src/lookup/phonetic_lookup_heap.h   | 23 ++++++++++++++++-------
 src/lookup/phonetic_lookup_linear.h |  8 ++++++--
 3 files changed, 44 insertions(+), 9 deletions(-)

(limited to 'src/lookup')

diff --git a/src/lookup/phonetic_lookup.h b/src/lookup/phonetic_lookup.h
index 065a31b..fc8272f 100644
--- a/src/lookup/phonetic_lookup.h
+++ b/src/lookup/phonetic_lookup.h
@@ -24,6 +24,7 @@
 
 #include "novel_types.h"
 #include <limits.h>
+#include <math.h>
 #include "phonetic_key_matrix.h"
 #include "ngram.h"
 
@@ -53,6 +54,27 @@ struct trellis_value_t {
     }
 };
 
+template <gint32 nbest>
+static bool inline trellis_value_less_than(const trellis_value_t * exist_item,
+                                           const trellis_value_t * new_item) {
+    /* shorter sentence */
+    if (exist_item->m_sentence_length > new_item->m_sentence_length ||
+        /* the same length but better possibility */
+        (exist_item->m_sentence_length == new_item->m_sentence_length &&
+         exist_item->m_poss < new_item->m_poss))
+        return true;
+
+    if (nbest > 1) {
+        /* allow longer sentence */
+        if (exist_item->m_current_index == 0 &&
+            exist_item->m_sentence_length == new_item->m_sentence_length + 1 &&
+            exist_item->m_poss < new_item->m_poss)
+            return true;
+    }
+
+    return false;
+}
+
 #if 0
 struct matrix_value_t {
     phrase_token_t m_cur_token;
diff --git a/src/lookup/phonetic_lookup_heap.h b/src/lookup/phonetic_lookup_heap.h
index cd9e2bc..4ceefde 100644
--- a/src/lookup/phonetic_lookup_heap.h
+++ b/src/lookup/phonetic_lookup_heap.h
@@ -21,10 +21,11 @@
 #ifndef PHONETIC_LOOKUP_HEAP_H
 #define PHONETIC_LOOKUP_HEAP_H
 
-static inline bool trellis_value_more_than(const trellis_value_t &lhs,
-                                           const trellis_value_t &rhs) {
+template <gint32 nbest>
+static inline bool trellis_value_more_than(const trellis_value_t &exist_item,
+                                           const trellis_value_t &new_item) {
     /* min heap here */
-    return lhs.m_poss > rhs.m_poss;
+    return trellis_value_less_than<nbest>(&new_item, &exist_item);
 }
 
 template <gint32 nbest>
@@ -58,7 +59,12 @@ public:
         if (m_nelem < nbest) {
             m_elements[m_nelem] = *item;
             m_nelem ++;
-            push_heap(begin(), end(), trellis_value_more_than);
+
+            /* mark the first slot of trellis_node. */
+            if (1 == m_nelem)
+                m_elements[0].m_current_index = 0;
+
+            push_heap(begin(), end(), trellis_value_more_than<nbest>);
             return true;
         }
 
@@ -67,9 +73,9 @@ public:
 
         /* compare new item */
         if (item->m_poss > min->m_poss) {
-            pop_heap(begin(), end(), trellis_value_more_than);
+            pop_heap(begin(), end(), trellis_value_more_than<nbest>);
             m_elements[m_nelem - 1] = *item;
-            push_heap(begin(), end(), trellis_value_more_than);
+            push_heap(begin(), end(), trellis_value_more_than<nbest>);
             return true;
         }
 
@@ -97,7 +103,10 @@ public:
 
     /* return true if the item is stored into m_element. */
     bool eval_item(const trellis_value_t * item) {
-        if (item->m_poss > m_element.m_poss) {
+        /* mark the first slot of trellis_node. */
+        m_element.m_current_index = 0;
+
+        if (compare_tellis_value<nbest>(&m_element, item)) {
             m_element = *item;
             return true;
         }
diff --git a/src/lookup/phonetic_lookup_linear.h b/src/lookup/phonetic_lookup_linear.h
index 9079c24..7bed44e 100644
--- a/src/lookup/phonetic_lookup_linear.h
+++ b/src/lookup/phonetic_lookup_linear.h
@@ -49,18 +49,22 @@ public:
         if (m_nelem < nbest) {
             m_elements[m_nelem] = *item;
             m_nelem ++;
+
+            /* mark the first slot of trellis_node. */
+            if (1 == m_nelem)
+                m_elements[0].m_current_index = 0;
             return true;
         }
 
         /* find minium item */
         trellis_value_t * min = m_elements;
         for (gint32 i = 1; i < m_nelem; ++i) {
-            if (min->m_poss > m_elements[i].m_poss)
+            if (trellis_value_less_than<nbest>(m_elements + i, min))
                 min = m_elements + i;
         }
 
         /* compare new item */
-        if (item->m_poss > min->m_poss) {
+        if (trellis_value_less_than<nbest>(min, item)) {
             *min = *item;
             return true;
         }
-- 
cgit