add value implementation for cherry c runtime system

runtime/CMakeLists.txt

+set(SOURCES
+  value.c)
+
+add_library(cherry-runtime SHARED ${SOURCES})
+target_link_libraries(cherry-runtime gc)
+

runtime/value.c

+/*
+ * Cherry programming language
+ * Copyright (C) 2013 Christoph Mueller
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "cherry/runtime.h"
+
+#include <gc.h>
+
+// ----------------------------------------------------------------------------
+// cherry object constructors
+// ----------------------------------------------------------------------------
+
+struct org_cherry_value* 	
+__org_cherry_make_fixnum(cy_fixnum_t value)
+{
+	struct org_cherry_value* cy_value = GC_MALLOC(sizeof(struct org_cherry_value));
+	cy_value->meta.type = CY_FIXNUM;
+	cy_value->fixnum_value = value;
+	return cy_value;
+}
+
+
+struct org_cherry_value* 	
+__org_cherry_make_float(cy_float_t value)
+{
+	struct org_cherry_value* cy_value = GC_MALLOC(sizeof(struct org_cherry_value));
+	cy_value->meta.type = CY_FLOAT;
+	cy_value->float_value = value;
+	return cy_value;
+}
+
+
+struct org_cherry_value* 	
+__org_cherry_make_string(cy_byte_t* value)
+{
+	struct org_cherry_value* cy_value = GC_MALLOC(sizeof(struct org_cherry_value));
+	cy_value->meta.type = CY_STRING;
+	cy_value->string_value = value;
+	return cy_value;
+}
+
+
+struct org_cherry_value* 	
+__org_cherry_make_char(cy_unicode_t value)
+{
+	struct org_cherry_value* cy_value = GC_MALLOC(sizeof(struct org_cherry_value));
+	cy_value->meta.type = CY_CHAR;
+	cy_value->char_value = value;
+	return cy_value;
+}
+
+// ----------------------------------------------------------------------------
+// cherry list operations
+// ----------------------------------------------------------------------------
+
+struct org_cherry_pair*     
+__org_cherry_list_cons(struct org_cherry_value* head, struct org_cherry_value* tail)
+{
+	struct org_cherry_pair* pair = GC_MALLOC(sizeof(struct org_cherry_pair));
+	pair->meta.type = CY_PAIR;
+	pair->head = head;
+	pair->tail = tail;
+	return pair;
+}
+
+struct org_cherry_value*    
+__org_cherry_list_head(struct org_cherry_pair* pair)
+{
+	return pair->head;
+}
+
+struct org_cherry_value*    
+__org_cherry_list_tail(struct org_cherry_pair* pair)
+{
+	return pair->tail;
+}
+
+struct org_cherry_value*    
+__org_cherry_list_length(struct org_cherry_pair* pair)
+{
+	cy_fixnum_t length = 0;
+
+	while(pair->meta.type == CY_PAIR) {
+		length++;
+		pair = (struct org_cherry_pair*) pair->tail;
+	}
+
+	return __org_cherry_make_fixnum(length);
+}
+
+struct org_cherry_value*
+__org_cherry_primitive_add(struct org_cherry_pair* pair)
+{
+	cy_fixnum_t result = 0;
+
+	while(pair->meta.type == CY_PAIR) {
+		result += pair->head->fixnum_value;
+		pair = (struct org_cherry_pair*) pair->tail;
+	}
+
+	return __org_cherry_make_fixnum(result);
+}
+
+