From 961136a41be89594c5a86b56af116c9c5af470a7 Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Thu, 19 Jan 2017 23:32:09 -0800
Subject: [PATCH] Add internal function, mostly for memory allocation and
 concatenation.

---
 src/pattern.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)

diff --git a/src/pattern.c b/src/pattern.c
index e69de29..dee0403 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -0,0 +1,131 @@
+#include "pattern.h"
+#include <stdlib.h>
+#include <string.h>
+
+void _pattern_node_clear(pattern_node* to_clear){
+  to_clear->type = PNODE_CLEAR;
+  to_clear->id = -1;
+  memset(&(to_clear->data_u), 0, sizeof(to_clear->data_u));
+}
+
+liblex_result _pattern_node_create_clear(pattern_node** into){
+  liblex_result result = LIBLEX_SUCCESS;
+  *into = malloc(sizeof(**into));
+  if(*into){
+    _pattern_node_clear(*into); 
+  } else {
+    result = LIBLEX_MALLOC;
+  }
+  return result;
+}
+
+liblex_result _pattern_node_create_value(pattern_node** into, int id, char value, pattern_node* next){
+  liblex_result result = _pattern_node_create_clear(into);
+  if(result == LIBLEX_SUCCESS){
+    (*into)->id = id;
+    (*into)->data_u.value_s.value = value;
+    (*into)->data_u.value_s.next = next;
+  }
+  return result;
+}
+
+liblex_result _pattern_node_create_range(pattern_node** into, int id, char from, char to, pattern_node* next){
+  liblex_result result = _pattern_node_create_clear(into);
+  if(result == LIBLEX_SUCCESS){
+    (*into)->id = id;
+    (*into)->data_u.range_s.from = from;
+    (*into)->data_u.range_s.to = to;
+    (*into)->data_u.range_s.next = next;
+  }
+  return result;
+}
+
+liblex_result _pattern_node_create_any(pattern_node** into, int id, pattern_node* next){
+  liblex_result result = _pattern_node_create_clear(into);
+  if(result == LIBLEX_SUCCESS){
+    (*into)->id = id;
+    (*into)->data_u.any_s.next = next;
+  }
+  return result;
+}
+
+liblex_result _pattern_node_create_connect(pattern_node** into, int id, pattern_node* next){
+  liblex_result result = _pattern_node_create_clear(into);
+  if(result == LIBLEX_SUCCESS){
+    (*into)->id = id;
+    (*into)->data_u.connect_s.next = next;
+  }
+  return result;
+}
+
+liblex_result _pattern_node_create_fork(pattern_node** into, int id, pattern_node* left, pattern_node* right){
+  liblex_result result = _pattern_node_create_clear(into);
+  if(result == LIBLEX_SUCCESS){
+    (*into)->id = id;
+    (*into)->data_u.fork_s.left = left;
+    (*into)->data_u.fork_s.right = right;
+  }
+  return result;
+}
+
+liblex_result _pattern_node_create_end(pattern_node** into, int id, int pattern_id){
+  liblex_result result = _pattern_node_create_clear(into);
+  if(result == LIBLEX_SUCCESS){
+    (*into)->id = id;
+    (*into)->data_u.end_s.pattern_id = pattern_id;
+  }
+  return result;
+}
+
+liblex_result _pattern_chain_create(pattern_chain** into, pattern_node* from, pattern_node* to){
+  liblex_result result = LIBLEX_SUCCESS;
+  *into = malloc(sizeof(**into));
+  if(*into){
+    (*into)->head = from;
+    (*into)->tail = to;
+  } else {
+    result = LIBLEX_SUCCESS;
+  }
+  return result;
+}
+
+pattern_node** _pattern_node_get_next(pattern_node* node) {
+  pattern_node** next_node = NULL;
+  if(node->type == PNODE_ANY){
+    next_node = &(node->data_u.any_s.next);
+  } else if(node->type == PNODE_RANGE){
+    next_node = &(node->data_u.range_s.next); 
+  } else if(node->type == PNODE_VALUE) {
+    next_node = &(node->data_u.value_s.next);
+  } else if(node->type == PNODE_CONNECT){
+    next_node = &(node->data_u.connect_s.next);
+  }
+  return next_node;
+}
+
+void _pattern_node_append_node(pattern_node* append_to, pattern_node* to_append){
+  if(append_to && to_append){
+    pattern_node** next_node = _pattern_node_get_next(append_to);
+    if(next_node){
+      *next_node = to_append;
+    }
+  }
+}
+
+void _pattern_chain_append_node(pattern_chain* append_to, pattern_node* to_append){
+  if(append_to && to_append){
+    pattern_node** next_node = (append_to->head) ? &append_to->head : _pattern_node_get_next(append_to->tail);
+    if(next_node) {
+      *next_node = append_to->tail = to_append;
+    }
+  }
+}
+
+void _pattern_chain_append_chain(pattern_chain* append_to, pattern_chain* to_append){
+  if(append_to && to_append){
+    _pattern_chain_append_node(append_to, to_append->head);
+    if(to_append->tail) {
+      append_to->tail = to_append->tail;
+    }
+  }
+}