implement basic matrix parsing

15 files changed, 2167 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..378eac2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..bf3ca8a
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.13)
+project(kalmia)
+
+option(KALMIA_BUILD_TESTS "Build the tests" ON)
+
+add_library(kalmia STATIC)
+target_include_directories(kalmia PUBLIC include)
+if (UNIX)
+	set_target_properties(
+		kalmia PROPERTIES
+		C_STANDARD 90
+		CMAKE_C_FLAGS "-Wall -Wextra -Werror -Wfatal-errors -Wpedantic"
+	)
+endif()
+
+if (KALMIA_BUILD_TESTS)
+	add_executable(kalmia-tests)
+	target_link_libraries(kalmia-tests kalmia)
+endif()
+
+add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/src)
diff --git a/example/white-cube.dae b/example/white-cube.dae
new file mode 100644
index 0000000..ddd1543
--- /dev/null
+++ b/example/white-cube.dae
@@ -0,0 +1,126 @@
+<?xml version="1.0" encoding="utf-8"?>
+<COLLADA xmlns="http://www.collada.org/2008/03/COLLADASchema" version="1.5.0">
+	<asset>
+		<created>2005-11-14T02:16:38Z</created>
+		<modified>2005-11-15T11:36:38Z</modified>
+		<revision>1.0</revision>
+	</asset>
+	<library_effects>
+		<effect id="whitePhong">
+			<profile_COMMON>
+				<technique sid="phong1">
+					<phong>
+						<emission>
+							<color>1.0 1.0 1.0 1.0</color>
+						</emission>
+						<ambient>
+							<color>1.0 1.0 1.0 1.0</color>
+						</ambient>
+						<diffuse>
+							<color>1.0 1.0 1.0 1.0</color>
+						</diffuse>
+						<specular>
+							<color>1.0 1.0 1.0 1.0</color>
+						</specular>
+						<shininess>
+							<float>20.0</float>
+						</shininess>
+						<reflective>
+							<color>1.0 1.0 1.0 1.0</color>
+						</reflective>
+						<reflectivity>
+							<float>0.5</float>
+						</reflectivity>
+						<transparent>
+							<color>1.0 1.0 1.0 1.0</color>
+						</transparent>
+						<transparency>
+							<float>1.0</float>
+						</transparency>
+					</phong>
+				</technique>
+			</profile_COMMON>
+		</effect>
+	</library_effects>
+	<library_materials>
+		<material id="whiteMaterial">
+			<instance_effect url="#whitePhong"/>
+		</material>
+	</library_materials>
+	<library_geometries>
+		<geometry id="box" name="box">
+			<mesh>
+				<source id="box-Pos">
+					<float_array id="box-Pos-array" count="24">
+						-0.5 0.5 0.5
+						0.5 0.5 0.5
+						-0.5 -0.5 0.5
+						0.5 -0.5 0.5
+						-0.5 0.5 -0.5
+						0.5 0.5 -0.5
+						-0.5 -0.5 -0.5
+						0.5 -0.5 -0.5
+					</float_array>
+					<technique_common>
+						<accessor source="#box-Pos-array" count="8" stride="3">
+							<param name="X" type="float" />
+							<param name="Y" type="float" />
+							<param name="Z" type="float" />
+						</accessor>
+					</technique_common>
+				</source>
+				<source id="box-0-Normal">
+					<float_array id="box-0-Normal-array" count="18">
+						1.0 0.0 0.0
+						-1.0 0.0 0.0
+						0.0 1.0 0.0
+						0.0 -1.0 0.0
+						0.0 0.0 1.0
+						0.0 0.0 -1.0
+					</float_array>
+					<technique_common>
+						<accessor source="#box-0-Normal-array" count="6" stride="3">
+							<param name="X" type="float"/>
+							<param name="Y" type="float"/>
+							<param name="Z" type="float"/>
+						</accessor>
+					</technique_common>
+				</source>
+				<vertices id="box-Vtx">
+					<input semantic="POSITION" source="#box-Pos"/>
+				</vertices>
+				<polygons count="6" material="WHITE">
+					<input semantic="VERTEX" source="#box-Vtx" offset="0"/>
+					<input semantic="NORMAL" source="#box-0-Normal" offset="1"/>
+					<p>0 4 2 4 3 4 1 4</p>
+					<p>0 2 1 2 5 2 4 2</p>
+					<p>6 3 7 3 3 3 2 3</p>
+					<p>0 1 4 1 6 1 2 1</p>
+					<p>3 0 7 0 5 0 1 0</p>
+					<p>5 5 7 5 6 5 4 5</p>
+				</polygons>
+			</mesh>
+		</geometry>
+	</library_geometries>
+	<library_visual_scenes>
+		<visual_scene id="DefaultScene">
+			<node id="Box" name="Box">
+				<translate> 0 0 0</translate>
+				<rotate> 0 0 1 0</rotate>
+				<rotate> 0 1 0 0</rotate>
+				<rotate> 1 0 0 0</rotate>
+				<scale> 1 1 1</scale>
+				<instance_geometry url="#box">
+					<bind_material>
+						<technique_common>
+							<instance_material symbol="WHITE" target="#whiteMaterial"/>
+						</technique_common>
+					</bind_material>
+				</instance_geometry>
+			</node>
+		</visual_scene>
+	</library_visual_scenes>
+	<scene>
+		<instance_visual_scene url="#DefaultScene"/>
+	</scene>
+</COLLADA>
diff --git a/include/kalmia.h b/include/kalmia.h
new file mode 100644
index 0000000..d01fb5d
--- /dev/null
+++ b/include/kalmia.h
@@ -0,0 +1,65 @@
+/****************************************************************
+ *
+ * ======== kalmia ========
+ *
+ * a COLLADA importer library
+ * copyright (c) 2022 kate swanson (sanine)
+ *
+ * This is anti-capitalist software, released for free use by individuals and
+ * organizations that do not operate by capitalist principles.
+ *
+ * Permission is hereby granted, free of charge, to any person or
+ * organization (the "User") obtaining a copy of this software and associated
+ * documentation files (the "Software"), to use, copy, modify, merge,
+ * distribute, and/or sell copies of the Software, subject to the following 
+ * conditions:
+ *
+ * 1. The above copyright notice and this permission notice shall be included
+ *    in all copies or modified versions of the Software.
+ *
+ * 2. The User is one of the following:
+ *    a. An individual person, laboring for themselves
+ *    b. A non-profit organization
+ *    c. An educational institution
+ *    d. An organization that seeks shared profit for all of its members, and
+ *       allows non-members to set the cost of their labor
+ *
+ * 3. If the User is an organization with owners, then all owners are workers
+ *    and all workers are owners with equal equity and/or equal vote.
+ *
+ * 4. If the User is an organization, then the User is not law enforcement or
+ *    military, or working for or under either.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT EXPRESS OR IMPLIED WARRANTY OF
+ * ANY KIND, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://anticapitalist.software/
+ * https://sanine.net
+ *
+ ****************************************************************/
+
+#ifndef KALMIA_H
+#define KALMIA_H
+
+/* kalmia uses semantic versioning (semver.org) */
+#define KALMIA_VERSION_MAJOR 0
+#define KALMIA_VERSION_MINOR 0
+#define KALMIA_VERSION_PATCH 0
+
+
+/* internal buffer size for strings/sids */
+#ifndef KA_BUF_SIZE
+#define KA_BUF_SIZE 128
+#endif
+
+
+/* format data structures */
+
+typedef double ka_matrix_t[16];
+
+
+#endif
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
new file mode 100644
index 0000000..a9067ca
--- /dev/null
+++ b/src/CMakeLists.txt
@@ -0,0 +1,17 @@
+project(kalmia)
+
+target_sources(kalmia PUBLIC transform.c)
+target_include_directories(kalmia PUBLIC ezxml)
+target_link_libraries(kalmia ezxml)
+
+add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/ezxml)
+
+if (KALMIA_BUILD_TESTS)
+	target_sources(
+		kalmia-tests PUBLIC
+		test/lily-test.c
+		test/test.c
+
+		transform.test.c
+	)
+endif()
diff --git a/src/ezxml/CMakeLists.txt b/src/ezxml/CMakeLists.txt
new file mode 100644
index 0000000..db024d9
--- /dev/null
+++ b/src/ezxml/CMakeLists.txt
@@ -0,0 +1,4 @@
+cmake_minimum_required(VERSION 3.2)
+project(ezxml)
+
+add_library(ezxml STATIC ezxml.c)
diff --git a/src/ezxml/ezxml.c b/src/ezxml/ezxml.c
new file mode 100644
index 0000000..82b11fb
--- /dev/null
+++ b/src/ezxml/ezxml.c
@@ -0,0 +1,1015 @@
+/* ezxml.c
+ *
+ * Copyright 2004-2006 Aaron Voisine <aaron@voisine.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <sys/types.h>
+#ifndef EZXML_NOMMAP
+#include <sys/mman.h>
+#endif // EZXML_NOMMAP
+#include <sys/stat.h>
+#include "ezxml.h"
+
+#define EZXML_WS   "\t\r\n "  // whitespace
+#define EZXML_ERRL 128        // maximum error string length
+
+typedef struct ezxml_root *ezxml_root_t;
+struct ezxml_root {       // additional data for the root tag
+    struct ezxml xml;     // is a super-struct built on top of ezxml struct
+    ezxml_t cur;          // current xml tree insertion point
+    char *m;              // original xml string
+    size_t len;           // length of allocated memory for mmap, -1 for malloc
+    char *u;              // UTF-8 conversion of string if original was UTF-16
+    char *s;              // start of work area
+    char *e;              // end of work area
+    char **ent;           // general entities (ampersand sequences)
+    char ***attr;         // default attributes
+    char ***pi;           // processing instructions
+    short standalone;     // non-zero if <?xml standalone="yes"?>
+    char err[EZXML_ERRL]; // error string
+};
+
+char *EZXML_NIL[] = { NULL }; // empty, null terminated array of strings
+
+// returns the first child tag with the given name or NULL if not found
+ezxml_t ezxml_child(ezxml_t xml, const char *name)
+{
+    xml = (xml) ? xml->child : NULL;
+    while (xml && strcmp(name, xml->name)) xml = xml->sibling;
+    return xml;
+}
+
+// returns the Nth tag with the same name in the same subsection or NULL if not
+// found
+ezxml_t ezxml_idx(ezxml_t xml, int idx)
+{
+    for (; xml && idx; idx--) xml = xml->next;
+    return xml;
+}
+
+// returns the value of the requested tag attribute or NULL if not found
+const char *ezxml_attr(ezxml_t xml, const char *attr)
+{
+    int i = 0, j = 1;
+    ezxml_root_t root = (ezxml_root_t)xml;
+
+    if (! xml || ! xml->attr) return NULL;
+    while (xml->attr[i] && strcmp(attr, xml->attr[i])) i += 2;
+    if (xml->attr[i]) return xml->attr[i + 1]; // found attribute
+
+    while (root->xml.parent) root = (ezxml_root_t)root->xml.parent; // root tag
+    for (i = 0; root->attr[i] && strcmp(xml->name, root->attr[i][0]); i++);
+    if (! root->attr[i]) return NULL; // no matching default attributes
+    while (root->attr[i][j] && strcmp(attr, root->attr[i][j])) j += 3;
+    return (root->attr[i][j]) ? root->attr[i][j + 1] : NULL; // found default
+}
+
+// same as ezxml_get but takes an already initialized va_list
+ezxml_t ezxml_vget(ezxml_t xml, va_list ap)
+{
+    char *name = va_arg(ap, char *);
+    int idx = -1;
+
+    if (name && *name) {
+        idx = va_arg(ap, int);    
+        xml = ezxml_child(xml, name);
+    }
+    return (idx < 0) ? xml : ezxml_vget(ezxml_idx(xml, idx), ap);
+}
+
+// Traverses the xml tree to retrieve a specific subtag. Takes a variable
+// length list of tag names and indexes. The argument list must be terminated
+// by either an index of -1 or an empty string tag name. Example: 
+// title = ezxml_get(library, "shelf", 0, "book", 2, "title", -1);
+// This retrieves the title of the 3rd book on the 1st shelf of library.
+// Returns NULL if not found.
+ezxml_t ezxml_get(ezxml_t xml, ...)
+{
+    va_list ap;
+    ezxml_t r;
+
+    va_start(ap, xml);
+    r = ezxml_vget(xml, ap);
+    va_end(ap);
+    return r;
+}
+
+// returns a null terminated array of processing instructions for the given
+// target
+const char **ezxml_pi(ezxml_t xml, const char *target)
+{
+    ezxml_root_t root = (ezxml_root_t)xml;
+    int i = 0;
+
+    if (! root) return (const char **)EZXML_NIL;
+    while (root->xml.parent) root = (ezxml_root_t)root->xml.parent; // root tag
+    while (root->pi[i] && strcmp(target, root->pi[i][0])) i++; // find target
+    return (const char **)((root->pi[i]) ? root->pi[i] + 1 : EZXML_NIL);
+}
+
+// set an error string and return root
+ezxml_t ezxml_err(ezxml_root_t root, char *s, const char *err, ...)
+{
+    va_list ap;
+    int line = 1;
+    char *t, fmt[EZXML_ERRL];
+    
+    for (t = root->s; t < s; t++) if (*t == '\n') line++;
+    snprintf(fmt, EZXML_ERRL, "[error near line %d]: %s", line, err);
+
+    va_start(ap, err);
+    vsnprintf(root->err, EZXML_ERRL, fmt, ap);
+    va_end(ap);
+
+    return &root->xml;
+}
+
+// Recursively decodes entity and character references and normalizes new lines
+// ent is a null terminated array of alternating entity names and values. set t
+// to '&' for general entity decoding, '%' for parameter entity decoding, 'c'
+// for cdata sections, ' ' for attribute normalization, or '*' for non-cdata
+// attribute normalization. Returns s, or if the decoded string is longer than
+// s, returns a malloced string that must be freed.
+char *ezxml_decode(char *s, char **ent, char t)
+{
+    char *e, *r = s, *m = s;
+    long b, c, d, l;
+
+    for (; *s; s++) { // normalize line endings
+        while (*s == '\r') {
+            *(s++) = '\n';
+            if (*s == '\n') memmove(s, (s + 1), strlen(s));
+        }
+    }
+    
+    for (s = r; ; ) {
+        while (*s && *s != '&' && (*s != '%' || t != '%') && !isspace(*s)) s++;
+
+        if (! *s) break;
+        else if (t != 'c' && ! strncmp(s, "&#", 2)) { // character reference
+            if (s[2] == 'x') c = strtol(s + 3, &e, 16); // base 16
+            else c = strtol(s + 2, &e, 10); // base 10
+            if (! c || *e != ';') { s++; continue; } // not a character ref
+
+            if (c < 0x80) *(s++) = c; // US-ASCII subset
+            else { // multi-byte UTF-8 sequence
+                for (b = 0, d = c; d; d /= 2) b++; // number of bits in c
+                b = (b - 2) / 5; // number of bytes in payload
+                *(s++) = (0xFF << (7 - b)) | (c >> (6 * b)); // head
+                while (b) *(s++) = 0x80 | ((c >> (6 * --b)) & 0x3F); // payload
+            }
+
+            memmove(s, strchr(s, ';') + 1, strlen(strchr(s, ';')));
+        }
+        else if ((*s == '&' && (t == '&' || t == ' ' || t == '*')) ||
+                 (*s == '%' && t == '%')) { // entity reference
+            for (b = 0; ent[b] && strncmp(s + 1, ent[b], strlen(ent[b]));
+                 b += 2); // find entity in entity list
+
+            if (ent[b++]) { // found a match
+                if ((c = strlen(ent[b])) - 1 > (e = strchr(s, ';')) - s) {
+                    l = (d = (s - r)) + c + strlen(e); // new length
+                    r = (r == m) ? strcpy(malloc(l), r) : realloc(r, l);
+                    e = strchr((s = r + d), ';'); // fix up pointers
+                }
+
+                memmove(s + c, e + 1, strlen(e)); // shift rest of string
+                strncpy(s, ent[b], c); // copy in replacement text
+            }
+            else s++; // not a known entity
+        }
+        else if ((t == ' ' || t == '*') && isspace(*s)) *(s++) = ' ';
+        else s++; // no decoding needed
+    }
+
+    if (t == '*') { // normalize spaces for non-cdata attributes
+        for (s = r; *s; s++) {
+            if ((l = strspn(s, " "))) memmove(s, s + l, strlen(s + l) + 1);
+            while (*s && *s != ' ') s++;
+        }
+        if (--s >= r && *s == ' ') *s = '\0'; // trim any trailing space
+    }
+    return r;
+}
+
+// called when parser finds start of new tag
+void ezxml_open_tag(ezxml_root_t root, char *name, char **attr)
+{
+    ezxml_t xml = root->cur;
+    
+    if (xml->name) xml = ezxml_add_child(xml, name, strlen(xml->txt));
+    else xml->name = name; // first open tag
+
+    xml->attr = attr;
+    root->cur = xml; // update tag insertion point
+}
+
+// called when parser finds character content between open and closing tag
+void ezxml_char_content(ezxml_root_t root, char *s, size_t len, char t)
+{
+    ezxml_t xml = root->cur;
+    char *m = s;
+    size_t l;
+
+    if (! xml || ! xml->name || ! len) return; // sanity check
+
+    s[len] = '\0'; // null terminate text (calling functions anticipate this)
+    len = strlen(s = ezxml_decode(s, root->ent, t)) + 1;
+
+    if (! *(xml->txt)) xml->txt = s; // initial character content
+    else { // allocate our own memory and make a copy
+        xml->txt = (xml->flags & EZXML_TXTM) // allocate some space
+                   ? realloc(xml->txt, (l = strlen(xml->txt)) + len)
+                   : strcpy(malloc((l = strlen(xml->txt)) + len), xml->txt);
+        strcpy(xml->txt + l, s); // add new char content
+        if (s != m) free(s); // free s if it was malloced by ezxml_decode()
+    }
+
+    if (xml->txt != m) ezxml_set_flag(xml, EZXML_TXTM);
+}
+
+// called when parser finds closing tag
+ezxml_t ezxml_close_tag(ezxml_root_t root, char *name, char *s)
+{
+    if (! root->cur || ! root->cur->name || strcmp(name, root->cur->name))
+        return ezxml_err(root, s, "unexpected closing tag </%s>", name);
+
+    root->cur = root->cur->parent;
+    return NULL;
+}
+
+// checks for circular entity references, returns non-zero if no circular
+// references are found, zero otherwise
+int ezxml_ent_ok(char *name, char *s, char **ent)
+{
+    int i;
+
+    for (; ; s++) {
+        while (*s && *s != '&') s++; // find next entity reference
+        if (! *s) return 1;
+        if (! strncmp(s + 1, name, strlen(name))) return 0; // circular ref.
+        for (i = 0; ent[i] && strncmp(ent[i], s + 1, strlen(ent[i])); i += 2);
+        if (ent[i] && ! ezxml_ent_ok(name, ent[i + 1], ent)) return 0;
+    }
+}
+
+// called when the parser finds a processing instruction
+void ezxml_proc_inst(ezxml_root_t root, char *s, size_t len)
+{
+    int i = 0, j = 1;
+    char *target = s;
+
+    s[len] = '\0'; // null terminate instruction
+    if (*(s += strcspn(s, EZXML_WS))) {
+        *s = '\0'; // null terminate target
+        s += strspn(s + 1, EZXML_WS) + 1; // skip whitespace after target
+    }
+
+    if (! strcmp(target, "xml")) { // <?xml ... ?>
+        if ((s = strstr(s, "standalone")) && ! strncmp(s + strspn(s + 10,
+            EZXML_WS "='\"") + 10, "yes", 3)) root->standalone = 1;
+        return;
+    }
+
+    if (! root->pi[0]) *(root->pi = malloc(sizeof(char **))) = NULL; //first pi
+
+    while (root->pi[i] && strcmp(target, root->pi[i][0])) i++; // find target
+    if (! root->pi[i]) { // new target
+        root->pi = realloc(root->pi, sizeof(char **) * (i + 2));
+        root->pi[i] = malloc(sizeof(char *) * 3);
+        root->pi[i][0] = target;
+        root->pi[i][1] = (char *)(root->pi[i + 1] = NULL); // terminate pi list
+        root->pi[i][2] = strdup(""); // empty document position list
+    }
+
+    while (root->pi[i][j]) j++; // find end of instruction list for this target
+    root->pi[i] = realloc(root->pi[i], sizeof(char *) * (j + 3));
+    root->pi[i][j + 2] = realloc(root->pi[i][j + 1], j + 1);
+    strcpy(root->pi[i][j + 2] + j - 1, (root->xml.name) ? ">" : "<");
+    root->pi[i][j + 1] = NULL; // null terminate pi list for this target
+    root->pi[i][j] = s; // set instruction
+}
+
+// called when the parser finds an internal doctype subset
+short ezxml_internal_dtd(ezxml_root_t root, char *s, size_t len)
+{
+    char q, *c, *t, *n = NULL, *v, **ent, **pe;
+    int i, j;
+    
+    pe = memcpy(malloc(sizeof(EZXML_NIL)), EZXML_NIL, sizeof(EZXML_NIL));
+
+    for (s[len] = '\0'; s; ) {
+        while (*s && *s != '<' && *s != '%') s++; // find next declaration
+
+        if (! *s) break;
+        else if (! strncmp(s, "<!ENTITY", 8)) { // parse entity definitions
+            c = s += strspn(s + 8, EZXML_WS) + 8; // skip white space separator
+            n = s + strspn(s, EZXML_WS "%"); // find name
+            *(s = n + strcspn(n, EZXML_WS)) = ';'; // append ; to name
+
+            v = s + strspn(s + 1, EZXML_WS) + 1; // find value
+            if ((q = *(v++)) != '"' && q != '\'') { // skip externals
+                s = strchr(s, '>');
+                continue;
+            }
+
+            for (i = 0, ent = (*c == '%') ? pe : root->ent; ent[i]; i++);
+            ent = realloc(ent, (i + 3) * sizeof(char *)); // space for next ent
+            if (*c == '%') pe = ent;
+            else root->ent = ent;
+
+            *(++s) = '\0'; // null terminate name
+            if ((s = strchr(v, q))) *(s++) = '\0'; // null terminate value
+            ent[i + 1] = ezxml_decode(v, pe, '%'); // set value
+            ent[i + 2] = NULL; // null terminate entity list
+            if (! ezxml_ent_ok(n, ent[i + 1], ent)) { // circular reference
+                if (ent[i + 1] != v) free(ent[i + 1]);
+                ezxml_err(root, v, "circular entity declaration &%s", n);
+                break;
+            }
+            else ent[i] = n; // set entity name
+        }
+        else if (! strncmp(s, "<!ATTLIST", 9)) { // parse default attributes
+            t = s + strspn(s + 9, EZXML_WS) + 9; // skip whitespace separator
+            if (! *t) { ezxml_err(root, t, "unclosed <!ATTLIST"); break; }
+            if (*(s = t + strcspn(t, EZXML_WS ">")) == '>') continue;
+            else *s = '\0'; // null terminate tag name
+            for (i = 0; root->attr[i] && strcmp(n, root->attr[i][0]); i++);
+
+            while (*(n = ++s + strspn(s, EZXML_WS)) && *n != '>') {
+                if (*(s = n + strcspn(n, EZXML_WS))) *s = '\0'; // attr name
+                else { ezxml_err(root, t, "malformed <!ATTLIST"); break; }
+
+                s += strspn(s + 1, EZXML_WS) + 1; // find next token
+                c = (strncmp(s, "CDATA", 5)) ? "*" : " "; // is it cdata?
+                if (! strncmp(s, "NOTATION", 8))
+                    s += strspn(s + 8, EZXML_WS) + 8;
+                s = (*s == '(') ? strchr(s, ')') : s + strcspn(s, EZXML_WS);
+                if (! s) { ezxml_err(root, t, "malformed <!ATTLIST"); break; }
+
+                s += strspn(s, EZXML_WS ")"); // skip white space separator
+                if (! strncmp(s, "#FIXED", 6))
+                    s += strspn(s + 6, EZXML_WS) + 6;
+                if (*s == '#') { // no default value
+                    s += strcspn(s, EZXML_WS ">") - 1;
+                    if (*c == ' ') continue; // cdata is default, nothing to do
+                    v = NULL;
+                }
+                else if ((*s == '"' || *s == '\'')  &&  // default value
+                         (s = strchr(v = s + 1, *s))) *s = '\0';
+                else { ezxml_err(root, t, "malformed <!ATTLIST"); break; }
+
+                if (! root->attr[i]) { // new tag name
+                    root->attr = (! i) ? malloc(2 * sizeof(char **))
+                                       : realloc(root->attr,
+                                                 (i + 2) * sizeof(char **));
+                    root->attr[i] = malloc(2 * sizeof(char *));
+                    root->attr[i][0] = t; // set tag name
+                    root->attr[i][1] = (char *)(root->attr[i + 1] = NULL);
+                }
+
+                for (j = 1; root->attr[i][j]; j += 3); // find end of list
+                root->attr[i] = realloc(root->attr[i],
+                                        (j + 4) * sizeof(char *));
+
+                root->attr[i][j + 3] = NULL; // null terminate list
+                root->attr[i][j + 2] = c; // is it cdata?
+                root->attr[i][j + 1] = (v) ? ezxml_decode(v, root->ent, *c)
+                                           : NULL;
+                root->attr[i][j] = n; // attribute name 
+            }
+        }
+        else if (! strncmp(s, "<!--", 4)) s = strstr(s + 4, "-->"); // comments
+        else if (! strncmp(s, "<?", 2)) { // processing instructions
+            if ((s = strstr(c = s + 2, "?>")))
+                ezxml_proc_inst(root, c, s++ - c);
+        }
+        else if (*s == '<') s = strchr(s, '>'); // skip other declarations
+        else if (*(s++) == '%' && ! root->standalone) break;
+    }
+
+    free(pe);
+    return ! *root->err;
+}
+
+// Converts a UTF-16 string to UTF-8. Returns a new string that must be freed
+// or NULL if no conversion was needed.
+char *ezxml_str2utf8(char **s, size_t *len)
+{
+    char *u;
+    size_t l = 0, sl, max = *len;
+    long c, d;
+    int b, be = (**s == '\xFE') ? 1 : (**s == '\xFF') ? 0 : -1;
+
+    if (be == -1) return NULL; // not UTF-16
+
+    u = malloc(max);
+    for (sl = 2; sl < *len - 1; sl += 2) {
+        c = (be) ? (((*s)[sl] & 0xFF) << 8) | ((*s)[sl + 1] & 0xFF)  //UTF-16BE
+                 : (((*s)[sl + 1] & 0xFF) << 8) | ((*s)[sl] & 0xFF); //UTF-16LE
+        if (c >= 0xD800 && c <= 0xDFFF && (sl += 2) < *len - 1) { // high-half
+            d = (be) ? (((*s)[sl] & 0xFF) << 8) | ((*s)[sl + 1] & 0xFF)
+                     : (((*s)[sl + 1] & 0xFF) << 8) | ((*s)[sl] & 0xFF);
+            c = (((c & 0x3FF) << 10) | (d & 0x3FF)) + 0x10000;
+        }
+
+        while (l + 6 > max) u = realloc(u, max += EZXML_BUFSIZE);
+        if (c < 0x80) u[l++] = c; // US-ASCII subset
+        else { // multi-byte UTF-8 sequence
+            for (b = 0, d = c; d; d /= 2) b++; // bits in c
+            b = (b - 2) / 5; // bytes in payload
+            u[l++] = (0xFF << (7 - b)) | (c >> (6 * b)); // head
+            while (b) u[l++] = 0x80 | ((c >> (6 * --b)) & 0x3F); // payload
+        }
+    }
+    return *s = realloc(u, *len = l);
+}
+
+// frees a tag attribute list
+void ezxml_free_attr(char **attr) {
+    int i = 0;
+    char *m;
+    
+    if (! attr || attr == EZXML_NIL) return; // nothing to free
+    while (attr[i]) i += 2; // find end of attribute list
+    m = attr[i + 1]; // list of which names and values are malloced
+    for (i = 0; m[i]; i++) {
+        if (m[i] & EZXML_NAMEM) free(attr[i * 2]);
+        if (m[i] & EZXML_TXTM) free(attr[(i * 2) + 1]);
+    }
+    free(m);
+    free(attr);
+}
+
+// parse the given xml string and return an ezxml structure
+ezxml_t ezxml_parse_str(char *s, size_t len)
+{
+    ezxml_root_t root = (ezxml_root_t)ezxml_new(NULL);
+    char q, e, *d, **attr, **a = NULL; // initialize a to avoid compile warning
+    int l, i, j;
+
+    root->m = s;
+    if (! len) return ezxml_err(root, NULL, "root tag missing");
+    root->u = ezxml_str2utf8(&s, &len); // convert utf-16 to utf-8
+    root->e = (root->s = s) + len; // record start and end of work area
+    
+    e = s[len - 1]; // save end char
+    s[len - 1] = '\0'; // turn end char into null terminator
+
+    while (*s && *s != '<') s++; // find first tag
+    if (! *s) return ezxml_err(root, s, "root tag missing");
+
+    for (; ; ) {
+        attr = (char **)EZXML_NIL;
+        d = ++s;
+        
+        if (isalpha(*s) || *s == '_' || *s == ':' || *s < '\0') { // new tag
+            if (! root->cur)
+                return ezxml_err(root, d, "markup outside of root element");
+
+            s += strcspn(s, EZXML_WS "/>");
+            while (isspace(*s)) *(s++) = '\0'; // null terminate tag name
+  
+            if (*s && *s != '/' && *s != '>') // find tag in default attr list
+                for (i = 0; (a = root->attr[i]) && strcmp(a[0], d); i++);
+
+            for (l = 0; *s && *s != '/' && *s != '>'; l += 2) { // new attrib
+                attr = (l) ? realloc(attr, (l + 4) * sizeof(char *))
+                           : malloc(4 * sizeof(char *)); // allocate space
+                attr[l + 3] = (l) ? realloc(attr[l + 1], (l / 2) + 2)
+                                  : malloc(2); // mem for list of maloced vals
+                strcpy(attr[l + 3] + (l / 2), " "); // value is not malloced
+                attr[l + 2] = NULL; // null terminate list
+                attr[l + 1] = ""; // temporary attribute value
+                attr[l] = s; // set attribute name
+
+                s += strcspn(s, EZXML_WS "=/>");
+                if (*s == '=' || isspace(*s)) { 
+                    *(s++) = '\0'; // null terminate tag attribute name
+                    q = *(s += strspn(s, EZXML_WS "="));
+                    if (q == '"' || q == '\'') { // attribute value
+                        attr[l + 1] = ++s;
+                        while (*s && *s != q) s++;
+                        if (*s) *(s++) = '\0'; // null terminate attribute val
+                        else {
+                            ezxml_free_attr(attr);
+                            return ezxml_err(root, d, "missing %c", q);
+                        }
+
+                        for (j = 1; a && a[j] && strcmp(a[j], attr[l]); j +=3);
+                        attr[l + 1] = ezxml_decode(attr[l + 1], root->ent, (a
+                                                   && a[j]) ? *a[j + 2] : ' ');
+                        if (attr[l + 1] < d || attr[l + 1] > s)
+                            attr[l + 3][l / 2] = EZXML_TXTM; // value malloced
+                    }
+                }
+                while (isspace(*s)) s++;
+            }
+
+            if (*s == '/') { // self closing tag
+                *(s++) = '\0';
+                if ((*s && *s != '>') || (! *s && e != '>')) {
+                    if (l) ezxml_free_attr(attr);
+                    return ezxml_err(root, d, "missing >");
+                }
+                ezxml_open_tag(root, d, attr);
+                ezxml_close_tag(root, d, s);
+            }
+            else if ((q = *s) == '>' || (! *s && e == '>')) { // open tag
+                *s = '\0'; // temporarily null terminate tag name
+                ezxml_open_tag(root, d, attr);
+                *s = q;
+            }
+            else {
+                if (l) ezxml_free_attr(attr);
+                return ezxml_err(root, d, "missing >"); 
+            }
+        }
+        else if (*s == '/') { // close tag
+            s += strcspn(d = s + 1, EZXML_WS ">") + 1;
+            if (! (q = *s) && e != '>') return ezxml_err(root, d, "missing >");
+            *s = '\0'; // temporarily null terminate tag name
+            if (ezxml_close_tag(root, d, s)) return &root->xml;
+            if (isspace(*s = q)) s += strspn(s, EZXML_WS);
+        }
+        else if (! strncmp(s, "!--", 3)) { // xml comment
+            if (! (s = strstr(s + 3, "--")) || (*(s += 2) != '>' && *s) ||
+                (! *s && e != '>')) return ezxml_err(root, d, "unclosed <!--");
+        }
+        else if (! strncmp(s, "![CDATA[", 8)) { // cdata
+            if ((s = strstr(s, "]]>")))
+                ezxml_char_content(root, d + 8, (s += 2) - d - 10, 'c');
+            else return ezxml_err(root, d, "unclosed <![CDATA[");
+        }
+        else if (! strncmp(s, "!DOCTYPE", 8)) { // dtd
+            for (l = 0; *s && ((! l && *s != '>') || (l && (*s != ']' || 
+                 *(s + strspn(s + 1, EZXML_WS) + 1) != '>')));
+                 l = (*s == '[') ? 1 : l) s += strcspn(s + 1, "[]>") + 1;
+            if (! *s && e != '>')
+                return ezxml_err(root, d, "unclosed <!DOCTYPE");
+            d = (l) ? strchr(d, '[') + 1 : d;
+            if (l && ! ezxml_internal_dtd(root, d, s++ - d)) return &root->xml;
+        }
+        else if (*s == '?') { // <?...?> processing instructions
+            do { s = strchr(s, '?'); } while (s && *(++s) && *s != '>');
+            if (! s || (! *s && e != '>')) 
+                return ezxml_err(root, d, "unclosed <?");
+            else ezxml_proc_inst(root, d + 1, s - d - 2);
+        }
+        else return ezxml_err(root, d, "unexpected <");
+        
+        if (! s || ! *s) break;
+        *s = '\0';
+        d = ++s;
+        if (*s && *s != '<') { // tag character content
+            while (*s && *s != '<') s++;
+            if (*s) ezxml_char_content(root, d, s - d, '&');
+            else break;
+        }
+        else if (! *s) break;
+    }
+
+    if (! root->cur) return &root->xml;
+    else if (! root->cur->name) return ezxml_err(root, d, "root tag missing");
+    else return ezxml_err(root, d, "unclosed tag <%s>", root->cur->name);
+}
+
+// Wrapper for ezxml_parse_str() that accepts a file stream. Reads the entire
+// stream into memory and then parses it. For xml files, use ezxml_parse_file()
+// or ezxml_parse_fd()
+ezxml_t ezxml_parse_fp(FILE *fp)
+{
+    ezxml_root_t root;
+    size_t l, len = 0;
+    char *s;
+
+    if (! (s = malloc(EZXML_BUFSIZE))) return NULL;
+    do {
+        len += (l = fread((s + len), 1, EZXML_BUFSIZE, fp));
+        if (l == EZXML_BUFSIZE) s = realloc(s, len + EZXML_BUFSIZE);
+    } while (s && l == EZXML_BUFSIZE);
+
+    if (! s) return NULL;
+    root = (ezxml_root_t)ezxml_parse_str(s, len);
+    root->len = -1; // so we know to free s in ezxml_free()
+    return &root->xml;
+}
+
+// A wrapper for ezxml_parse_str() that accepts a file descriptor. First
+// attempts to mem map the file. Failing that, reads the file into memory.
+// Returns NULL on failure.
+ezxml_t ezxml_parse_fd(int fd)
+{
+    ezxml_root_t root;
+    struct stat st;
+    size_t l;
+    void *m;
+
+    if (fd < 0) return NULL;
+    fstat(fd, &st);
+
+#ifndef EZXML_NOMMAP
+    l = (st.st_size + sysconf(_SC_PAGESIZE) - 1) & ~(sysconf(_SC_PAGESIZE) -1);
+    if ((m = mmap(NULL, l, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0)) !=
+        MAP_FAILED) {
+        madvise(m, l, MADV_SEQUENTIAL); // optimize for sequential access
+        root = (ezxml_root_t)ezxml_parse_str(m, st.st_size);
+        madvise(m, root->len = l, MADV_NORMAL); // put it back to normal
+    }
+    else { // mmap failed, read file into memory
+#endif // EZXML_NOMMAP
+        l = read(fd, m = malloc(st.st_size), st.st_size);
+        root = (ezxml_root_t)ezxml_parse_str(m, l);
+        root->len = -1; // so we know to free s in ezxml_free()
+#ifndef EZXML_NOMMAP
+    }
+#endif // EZXML_NOMMAP
+    return &root->xml;
+}
+
+// a wrapper for ezxml_parse_fd that accepts a file name
+ezxml_t ezxml_parse_file(const char *file)
+{
+    int fd = open(file, O_RDONLY, 0);
+    ezxml_t xml = ezxml_parse_fd(fd);
+    
+    if (fd >= 0) close(fd);
+    return xml;
+}
+
+// Encodes ampersand sequences appending the results to *dst, reallocating *dst
+// if length excedes max. a is non-zero for attribute encoding. Returns *dst
+char *ezxml_ampencode(const char *s, size_t len, char **dst, size_t *dlen,
+                      size_t *max, short a)
+{
+    const char *e;
+    
+    for (e = s + len; s != e; s++) {
+        while (*dlen + 10 > *max) *dst = realloc(*dst, *max += EZXML_BUFSIZE);
+
+        switch (*s) {
+        case '\0': return *dst;
+        case '&': *dlen += sprintf(*dst + *dlen, "&amp;"); break;
+        case '<': *dlen += sprintf(*dst + *dlen, "&lt;"); break;
+        case '>': *dlen += sprintf(*dst + *dlen, "&gt;"); break;
+        case '"': *dlen += sprintf(*dst + *dlen, (a) ? "&quot;" : "\""); break;
+        case '\n': *dlen += sprintf(*dst + *dlen, (a) ? "&#xA;" : "\n"); break;
+        case '\t': *dlen += sprintf(*dst + *dlen, (a) ? "&#x9;" : "\t"); break;
+        case '\r': *dlen += sprintf(*dst + *dlen, "&#xD;"); break;
+        default: (*dst)[(*dlen)++] = *s;
+        }
+    }
+    return *dst;
+}
+
+// Recursively converts each tag to xml appending it to *s. Reallocates *s if
+// its length excedes max. start is the location of the previous tag in the
+// parent tag's character content. Returns *s.
+char *ezxml_toxml_r(ezxml_t xml, char **s, size_t *len, size_t *max,
+                    size_t start, char ***attr)
+{
+    int i, j;
+    char *txt = (xml->parent) ? xml->parent->txt : "";
+    size_t off = 0;
+
+    // parent character content up to this tag
+    *s = ezxml_ampencode(txt + start, xml->off - start, s, len, max, 0);
+
+    while (*len + strlen(xml->name) + 4 > *max) // reallocate s
+        *s = realloc(*s, *max += EZXML_BUFSIZE);
+
+    *len += sprintf(*s + *len, "<%s", xml->name); // open tag
+    for (i = 0; xml->attr[i]; i += 2) { // tag attributes
+        if (ezxml_attr(xml, xml->attr[i]) != xml->attr[i + 1]) continue;
+        while (*len + strlen(xml->attr[i]) + 7 > *max) // reallocate s
+            *s = realloc(*s, *max += EZXML_BUFSIZE);
+
+        *len += sprintf(*s + *len, " %s=\"", xml->attr[i]);
+        ezxml_ampencode(xml->attr[i + 1], -1, s, len, max, 1);
+        *len += sprintf(*s + *len, "\"");
+    }
+
+    for (i = 0; attr[i] && strcmp(attr[i][0], xml->name); i++);
+    for (j = 1; attr[i] && attr[i][j]; j += 3) { // default attributes
+        if (! attr[i][j + 1] || ezxml_attr(xml, attr[i][j]) != attr[i][j + 1])
+            continue; // skip duplicates and non-values
+        while (*len + strlen(attr[i][j]) + 7 > *max) // reallocate s
+            *s = realloc(*s, *max += EZXML_BUFSIZE);
+
+        *len += sprintf(*s + *len, " %s=\"", attr[i][j]);
+        ezxml_ampencode(attr[i][j + 1], -1, s, len, max, 1);
+        *len += sprintf(*s + *len, "\"");
+    }
+    *len += sprintf(*s + *len, ">");
+
+    *s = (xml->child) ? ezxml_toxml_r(xml->child, s, len, max, 0, attr) //child
+                      : ezxml_ampencode(xml->txt, -1, s, len, max, 0);  //data
+    
+    while (*len + strlen(xml->name) + 4 > *max) // reallocate s
+        *s = realloc(*s, *max += EZXML_BUFSIZE);
+
+    *len += sprintf(*s + *len, "</%s>", xml->name); // close tag
+
+    while (txt[off] && off < xml->off) off++; // make sure off is within bounds
+    return (xml->ordered) ? ezxml_toxml_r(xml->ordered, s, len, max, off, attr)
+                          : ezxml_ampencode(txt + off, -1, s, len, max, 0);
+}
+
+// Converts an ezxml structure back to xml. Returns a string of xml data that
+// must be freed.
+char *ezxml_toxml(ezxml_t xml)
+{
+    ezxml_t p = (xml) ? xml->parent : NULL, o = (xml) ? xml->ordered : NULL;
+    ezxml_root_t root = (ezxml_root_t)xml;
+    size_t len = 0, max = EZXML_BUFSIZE;
+    char *s = strcpy(malloc(max), ""), *t, *n;
+    int i, j, k;
+
+    if (! xml || ! xml->name) return realloc(s, len + 1);
+    while (root->xml.parent) root = (ezxml_root_t)root->xml.parent; // root tag
+
+    for (i = 0; ! p && root->pi[i]; i++) { // pre-root processing instructions
+        for (k = 2; root->pi[i][k - 1]; k++);
+        for (j = 1; (n = root->pi[i][j]); j++) {
+            if (root->pi[i][k][j - 1] == '>') continue; // not pre-root
+            while (len + strlen(t = root->pi[i][0]) + strlen(n) + 7 > max)
+                s = realloc(s, max += EZXML_BUFSIZE);
+            len += sprintf(s + len, "<?%s%s%s?>\n", t, *n ? " " : "", n);
+        }
+    }
+
+    xml->parent = xml->ordered = NULL;
+    s = ezxml_toxml_r(xml, &s, &len, &max, 0, root->attr);
+    xml->parent = p;
+    xml->ordered = o;
+
+    for (i = 0; ! p && root->pi[i]; i++) { // post-root processing instructions
+        for (k = 2; root->pi[i][k - 1]; k++);
+        for (j = 1; (n = root->pi[i][j]); j++) {
+            if (root->pi[i][k][j - 1] == '<') continue; // not post-root
+            while (len + strlen(t = root->pi[i][0]) + strlen(n) + 7 > max)
+                s = realloc(s, max += EZXML_BUFSIZE);
+            len += sprintf(s + len, "\n<?%s%s%s?>", t, *n ? " " : "", n);
+        }
+    }
+    return realloc(s, len + 1);
+}
+
+// free the memory allocated for the ezxml structure
+void ezxml_free(ezxml_t xml)
+{
+    ezxml_root_t root = (ezxml_root_t)xml;
+    int i, j;
+    char **a, *s;
+
+    if (! xml) return;
+    ezxml_free(xml->child);
+    ezxml_free(xml->ordered);
+
+    if (! xml->parent) { // free root tag allocations
+        for (i = 10; root->ent[i]; i += 2) // 0 - 9 are default entites (<>&"')
+            if ((s = root->ent[i + 1]) < root->s || s > root->e) free(s);
+        free(root->ent); // free list of general entities
+
+        for (i = 0; (a = root->attr[i]); i++) {
+            for (j = 1; a[j++]; j += 2) // free malloced attribute values
+                if (a[j] && (a[j] < root->s || a[j] > root->e)) free(a[j]);
+            free(a);
+        }
+        if (root->attr[0]) free(root->attr); // free default attribute list
+
+        for (i = 0; root->pi[i]; i++) {
+            for (j = 1; root->pi[i][j]; j++);
+            free(root->pi[i][j + 1]);
+            free(root->pi[i]);
+        }            
+        if (root->pi[0]) free(root->pi); // free processing instructions
+
+        if (root->len == -1) free(root->m); // malloced xml data
+#ifndef EZXML_NOMMAP
+        else if (root->len) munmap(root->m, root->len); // mem mapped xml data
+#endif // EZXML_NOMMAP
+        if (root->u) free(root->u); // utf8 conversion
+    }
+
+    ezxml_free_attr(xml->attr); // tag attributes
+    if ((xml->flags & EZXML_TXTM)) free(xml->txt); // character content
+    if ((xml->flags & EZXML_NAMEM)) free(xml->name); // tag name
+    free(xml);
+}
+
+// return parser error message or empty string if none
+const char *ezxml_error(ezxml_t xml)
+{
+    while (xml && xml->parent) xml = xml->parent; // find root tag
+    return (xml) ? ((ezxml_root_t)xml)->err : "";
+}
+
+// returns a new empty ezxml structure with the given root tag name
+ezxml_t ezxml_new(const char *name)
+{
+    static char *ent[] = { "lt;", "&#60;", "gt;", "&#62;", "quot;", "&#34;",
+                           "apos;", "&#39;", "amp;", "&#38;", NULL };
+    ezxml_root_t root = (ezxml_root_t)memset(malloc(sizeof(struct ezxml_root)), 
+                                             '\0', sizeof(struct ezxml_root));
+    root->xml.name = (char *)name;
+    root->cur = &root->xml;
+    strcpy(root->err, root->xml.txt = "");
+    root->ent = memcpy(malloc(sizeof(ent)), ent, sizeof(ent));
+    root->attr = root->pi = (char ***)(root->xml.attr = EZXML_NIL);
+    return &root->xml;
+}
+
+// inserts an existing tag into an ezxml structure
+ezxml_t ezxml_insert(ezxml_t xml, ezxml_t dest, size_t off)
+{
+    ezxml_t cur, prev, head;
+
+    xml->next = xml->sibling = xml->ordered = NULL;
+    xml->off = off;
+    xml->parent = dest;
+
+    if ((head = dest->child)) { // already have sub tags
+        if (head->off <= off) { // not first subtag
+            for (cur = head; cur->ordered && cur->ordered->off <= off;
+                 cur = cur->ordered);
+            xml->ordered = cur->ordered;
+            cur->ordered = xml;
+        }
+        else { // first subtag
+            xml->ordered = head;
+            dest->child = xml;
+        }
+
+        for (cur = head, prev = NULL; cur && strcmp(cur->name, xml->name);
+             prev = cur, cur = cur->sibling); // find tag type
+        if (cur && cur->off <= off) { // not first of type
+            while (cur->next && cur->next->off <= off) cur = cur->next;
+            xml->next = cur->next;
+            cur->next = xml;
+        }
+        else { // first tag of this type
+            if (prev && cur) prev->sibling = cur->sibling; // remove old first
+            xml->next = cur; // old first tag is now next
+            for (cur = head, prev = NULL; cur && cur->off <= off;
+                 prev = cur, cur = cur->sibling); // new sibling insert point
+            xml->sibling = cur;
+            if (prev) prev->sibling = xml;
+        }
+    }
+    else dest->child = xml; // only sub tag
+
+    return xml;
+}
+
+// Adds a child tag. off is the offset of the child tag relative to the start
+// of the parent tag's character content. Returns the child tag.
+ezxml_t ezxml_add_child(ezxml_t xml, const char *name, size_t off)
+{
+    ezxml_t child;
+
+    if (! xml) return NULL;
+    child = (ezxml_t)memset(malloc(sizeof(struct ezxml)), '\0',
+                            sizeof(struct ezxml));
+    child->name = (char *)name;
+    child->attr = EZXML_NIL;
+    child->txt = "";
+
+    return ezxml_insert(child, xml, off);
+}
+
+// sets the character content for the given tag and returns the tag
+ezxml_t ezxml_set_txt(ezxml_t xml, const char *txt)
+{
+    if (! xml) return NULL;
+    if (xml->flags & EZXML_TXTM) free(xml->txt); // existing txt was malloced
+    xml->flags &= ~EZXML_TXTM;
+    xml->txt = (char *)txt;
+    return xml;
+}
+
+// Sets the given tag attribute or adds a new attribute if not found. A value
+// of NULL will remove the specified attribute. Returns the tag given.
+ezxml_t ezxml_set_attr(ezxml_t xml, const char *name, const char *value)
+{
+    int l = 0, c;
+
+    if (! xml) return NULL;
+    while (xml->attr[l] && strcmp(xml->attr[l], name)) l += 2;
+    if (! xml->attr[l]) { // not found, add as new attribute
+        if (! value) return xml; // nothing to do
+        if (xml->attr == EZXML_NIL) { // first attribute
+            xml->attr = malloc(4 * sizeof(char *));
+            xml->attr[1] = strdup(""); // empty list of malloced names/vals
+        }
+        else xml->attr = realloc(xml->attr, (l + 4) * sizeof(char *));
+
+        xml->attr[l] = (char *)name; // set attribute name
+        xml->attr[l + 2] = NULL; // null terminate attribute list
+        xml->attr[l + 3] = realloc(xml->attr[l + 1],
+                                   (c = strlen(xml->attr[l + 1])) + 2);
+        strcpy(xml->attr[l + 3] + c, " "); // set name/value as not malloced
+        if (xml->flags & EZXML_DUP) xml->attr[l + 3][c] = EZXML_NAMEM;
+    }
+    else if (xml->flags & EZXML_DUP) free((char *)name); // name was strduped
+
+    for (c = l; xml->attr[c]; c += 2); // find end of attribute list
+    if (xml->attr[c + 1][l / 2] & EZXML_TXTM) free(xml->attr[l + 1]); //old val
+    if (xml->flags & EZXML_DUP) xml->attr[c + 1][l / 2] |= EZXML_TXTM;
+    else xml->attr[c + 1][l / 2] &= ~EZXML_TXTM;
+
+    if (value) xml->attr[l + 1] = (char *)value; // set attribute value
+    else { // remove attribute
+        if (xml->attr[c + 1][l / 2] & EZXML_NAMEM) free(xml->attr[l]);
+        memmove(xml->attr + l, xml->attr + l + 2, (c - l + 2) * sizeof(char*));
+        xml->attr = realloc(xml->attr, (c + 2) * sizeof(char *));
+        memmove(xml->attr[c + 1] + (l / 2), xml->attr[c + 1] + (l / 2) + 1,
+                (c / 2) - (l / 2)); // fix list of which name/vals are malloced
+    }
+    xml->flags &= ~EZXML_DUP; // clear strdup() flag
+    return xml;
+}
+
+// sets a flag for the given tag and returns the tag
+ezxml_t ezxml_set_flag(ezxml_t xml, short flag)
+{
+    if (xml) xml->flags |= flag;
+    return xml;
+}
+
+// removes a tag along with its subtags without freeing its memory
+ezxml_t ezxml_cut(ezxml_t xml)
+{
+    ezxml_t cur;
+
+    if (! xml) return NULL; // nothing to do
+    if (xml->next) xml->next->sibling = xml->sibling; // patch sibling list
+
+    if (xml->parent) { // not root tag
+        cur = xml->parent->child; // find head of subtag list
+        if (cur == xml) xml->parent->child = xml->ordered; // first subtag
+        else { // not first subtag
+            while (cur->ordered != xml) cur = cur->ordered;
+            cur->ordered = cur->ordered->ordered; // patch ordered list
+
+            cur = xml->parent->child; // go back to head of subtag list
+            if (strcmp(cur->name, xml->name)) { // not in first sibling list
+                while (strcmp(cur->sibling->name, xml->name))
+                    cur = cur->sibling;
+                if (cur->sibling == xml) { // first of a sibling list
+                    cur->sibling = (xml->next) ? xml->next
+                                               : cur->sibling->sibling;
+                }
+                else cur = cur->sibling; // not first of a sibling list
+            }
+
+            while (cur->next && cur->next != xml) cur = cur->next;
+            if (cur->next) cur->next = cur->next->next; // patch next list
+        }        
+    }
+    xml->ordered = xml->sibling = xml->next = NULL;
+    return xml;
+}
+
+#ifdef EZXML_TEST // test harness
+int main(int argc, char **argv)
+{
+    ezxml_t xml;
+    char *s;
+    int i;
+
+    if (argc != 2) return fprintf(stderr, "usage: %s xmlfile\n", argv[0]);
+
+    xml = ezxml_parse_file(argv[1]);
+    printf("%s\n", (s = ezxml_toxml(xml)));
+    free(s);
+    i = fprintf(stderr, "%s", ezxml_error(xml));
+    ezxml_free(xml);
+    return (i) ? 1 : 0;
+}
+#endif // EZXML_TEST
diff --git a/src/ezxml/ezxml.h b/src/ezxml/ezxml.h
new file mode 100644
index 0000000..3e02078
--- /dev/null
+++ b/src/ezxml/ezxml.h
@@ -0,0 +1,167 @@
+/* ezxml.h
+ *
+ * Copyright 2004-2006 Aaron Voisine <aaron@voisine.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _EZXML_H
+#define _EZXML_H
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <fcntl.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define EZXML_BUFSIZE 1024 // size of internal memory buffers
+#define EZXML_NAMEM   0x80 // name is malloced
+#define EZXML_TXTM    0x40 // txt is malloced
+#define EZXML_DUP     0x20 // attribute name and value are strduped
+
+typedef struct ezxml *ezxml_t;
+struct ezxml {
+    char *name;      // tag name
+    char **attr;     // tag attributes { name, value, name, value, ... NULL }
+    char *txt;       // tag character content, empty string if none
+    size_t off;      // tag offset from start of parent tag character content
+    ezxml_t next;    // next tag with same name in this section at this depth
+    ezxml_t sibling; // next tag with different name in same section and depth
+    ezxml_t ordered; // next tag, same section and depth, in original order
+    ezxml_t child;   // head of sub tag list, NULL if none
+    ezxml_t parent;  // parent tag, NULL if current tag is root tag
+    short flags;     // additional information
+};
+
+// Given a string of xml data and its length, parses it and creates an ezxml
+// structure. For efficiency, modifies the data by adding null terminators
+// and decoding ampersand sequences. If you don't want this, copy the data and
+// pass in the copy. Returns NULL on failure.
+ezxml_t ezxml_parse_str(char *s, size_t len);
+
+// A wrapper for ezxml_parse_str() that accepts a file descriptor. First
+// attempts to mem map the file. Failing that, reads the file into memory.
+// Returns NULL on failure.
+ezxml_t ezxml_parse_fd(int fd);
+
+// a wrapper for ezxml_parse_fd() that accepts a file name
+ezxml_t ezxml_parse_file(const char *file);
+    
+// Wrapper for ezxml_parse_str() that accepts a file stream. Reads the entire
+// stream into memory and then parses it. For xml files, use ezxml_parse_file()
+// or ezxml_parse_fd()
+ezxml_t ezxml_parse_fp(FILE *fp);
+
+// returns the first child tag (one level deeper) with the given name or NULL
+// if not found
+ezxml_t ezxml_child(ezxml_t xml, const char *name);
+
+// returns the next tag of the same name in the same section and depth or NULL
+// if not found
+#define ezxml_next(xml) ((xml) ? xml->next : NULL)
+
+// Returns the Nth tag with the same name in the same section at the same depth
+// or NULL if not found. An index of 0 returns the tag given.
+ezxml_t ezxml_idx(ezxml_t xml, int idx);
+
+// returns the name of the given tag
+#define ezxml_name(xml) ((xml) ? xml->name : NULL)
+
+// returns the given tag's character content or empty string if none
+#define ezxml_txt(xml) ((xml) ? xml->txt : "")
+
+// returns the value of the requested tag attribute, or NULL if not found
+const char *ezxml_attr(ezxml_t xml, const char *attr);
+
+// Traverses the ezxml sturcture to retrieve a specific subtag. Takes a
+// variable length list of tag names and indexes. The argument list must be
+// terminated by either an index of -1 or an empty string tag name. Example: 
+// title = ezxml_get(library, "shelf", 0, "book", 2, "title", -1);
+// This retrieves the title of the 3rd book on the 1st shelf of library.
+// Returns NULL if not found.
+ezxml_t ezxml_get(ezxml_t xml, ...);
+
+// Converts an ezxml structure back to xml. Returns a string of xml data that
+// must be freed.
+char *ezxml_toxml(ezxml_t xml);
+
+// returns a NULL terminated array of processing instructions for the given
+// target
+const char **ezxml_pi(ezxml_t xml, const char *target);
+
+// frees the memory allocated for an ezxml structure
+void ezxml_free(ezxml_t xml);
+    
+// returns parser error message or empty string if none
+const char *ezxml_error(ezxml_t xml);
+
+// returns a new empty ezxml structure with the given root tag name
+ezxml_t ezxml_new(const char *name);
+
+// wrapper for ezxml_new() that strdup()s name
+#define ezxml_new_d(name) ezxml_set_flag(ezxml_new(strdup(name)), EZXML_NAMEM)
+
+// Adds a child tag. off is the offset of the child tag relative to the start
+// of the parent tag's character content. Returns the child tag.
+ezxml_t ezxml_add_child(ezxml_t xml, const char *name, size_t off);
+
+// wrapper for ezxml_add_child() that strdup()s name
+#define ezxml_add_child_d(xml, name, off) \
+    ezxml_set_flag(ezxml_add_child(xml, strdup(name), off), EZXML_NAMEM)
+
+// sets the character content for the given tag and returns the tag
+ezxml_t ezxml_set_txt(ezxml_t xml, const char *txt);
+
+// wrapper for ezxml_set_txt() that strdup()s txt
+#define ezxml_set_txt_d(xml, txt) \
+    ezxml_set_flag(ezxml_set_txt(xml, strdup(txt)), EZXML_TXTM)
+
+// Sets the given tag attribute or adds a new attribute if not found. A value
+// of NULL will remove the specified attribute. Returns the tag given.
+ezxml_t ezxml_set_attr(ezxml_t xml, const char *name, const char *value);
+
+// Wrapper for ezxml_set_attr() that strdup()s name/value. Value cannot be NULL
+#define ezxml_set_attr_d(xml, name, value) \
+    ezxml_set_attr(ezxml_set_flag(xml, EZXML_DUP), strdup(name), strdup(value))
+
+// sets a flag for the given tag and returns the tag
+ezxml_t ezxml_set_flag(ezxml_t xml, short flag);
+
+// removes a tag along with its subtags without freeing its memory
+ezxml_t ezxml_cut(ezxml_t xml);
+
+// inserts an existing tag into an ezxml structure
+ezxml_t ezxml_insert(ezxml_t xml, ezxml_t dest, size_t off);
+
+// Moves an existing tag to become a subtag of dest at the given offset from
+// the start of dest's character content. Returns the moved tag.
+#define ezxml_move(xml, dest, off) ezxml_insert(ezxml_cut(xml), dest, off)
+
+// removes a tag along with all its subtags
+#define ezxml_remove(xml) ezxml_free(ezxml_cut(xml))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _EZXML_H
diff --git a/src/test/lily-test.c b/src/test/lily-test.c
new file mode 100644
index 0000000..30f96d5
--- /dev/null
+++ b/src/test/lily-test.c
@@ -0,0 +1,366 @@
+/****************************************************************
+ *
+ * ======== lily-test ========
+ *
+ * a midsize C unit testing library
+ * copyright (c) 2022 kate swanson (sanine)
+ *
+ * This is anti-capitalist software, released for free use by individuals and
+ * organizations that do not operate by capitalist principles.
+ *
+ * Permission is hereby granted, free of charge, to any person or
+ * organization (the "User") obtaining a copy of this software and associated
+ * documentation files (the "Software"), to use, copy, modify, merge,
+ * distribute, and/or sell copies of the Software, subject to the following 
+ * conditions:
+ *
+ * 1. The above copyright notice and this permission notice shall be included
+ *    in all copies or modified versions of the Software.
+ *
+ * 2. The User is one of the following:
+ *    a. An individual person, laboring for themselves
+ *    b. A non-profit organization
+ *    c. An educational institution
+ *    d. An organization that seeks shared profit for all of its members, and
+ *       allows non-members to set the cost of their labor
+ *
+ * 3. If the User is an organization with owners, then all owners are workers
+ *    and all workers are owners with equal equity and/or equal vote.
+ *
+ * 4. If the User is an organization, then the User is not law enforcement or
+ *    military, or working for or under either.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT EXPRESS OR IMPLIED WARRANTY OF
+ * ANY KIND, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://anticapitalist.software/
+ * https://sanine.net
+ *
+ ****************************************************************/
+
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "lily-test.h"
+
+struct lily_globals_t _lily_globals = { {0}, 0, NULL, "" };
+
+/* run an individual test */
+void _lily_run_test(const char *name, lily_test_t test)
+{
+	printf("  %s: ", name);
+
+	_lily_globals.error_msg = NULL;
+	_lily_globals.error_location = "";
+	int val = setjmp(_lily_globals.env);
+
+	if (val) {
+	/* test failed */
+		printf("FAIL - %s (%s)\n",
+		  _lily_globals.error_msg,
+		  _lily_globals.error_location);
+		free(_lily_globals.error_msg); /* error message was allocated! */
+	  return;
+	}
+
+	test();
+
+	/* test succeeded */
+	printf("OK\n");
+}
+
+/* run a suite */
+void _lily_run_suite(const char *name, lily_test_t suite)
+{
+	printf("=== %s ===\n", name);
+	suite();
+	printf("\n");
+}
+
+
+/* ======== ASSERTIONS ======== */
+
+static void _lily_assert_msg(bool statement, const char *location,
+				  const char *format_string, va_list args)
+{
+	if (statement) {
+		va_end(args);
+		return; // no error, return
+	}
+
+	_lily_globals.error_location = location;
+
+	va_list args_len;
+	va_copy(args_len, args);
+	size_t length = vsnprintf(NULL, 0, format_string, args_len);
+	va_end(args_len);
+
+	if (_lily_globals.error_msg_len < length+1 ||
+		 _lily_globals.error_msg == NULL) {
+		if (_lily_globals.error_msg != NULL)
+	 free(_lily_globals.error_msg);
+
+		char *msg = malloc((length+2) * sizeof(char));
+
+		if (msg == NULL) {
+	 fprintf(stderr, "WARNING: failed to allocate memory for failed test message!\n");
+	 _lily_globals.error_msg = NULL;
+	 va_end(args);
+	 longjmp(_lily_globals.env, 1);
+	 return;
+		}
+		else {
+	 _lily_globals.error_msg = msg;
+	 _lily_globals.error_msg_len = length+1;
+		}
+	}
+
+	vsnprintf(_lily_globals.error_msg, length+1, format_string, args);
+
+	va_end(args);
+	longjmp(_lily_globals.env, 1);
+}
+
+
+void lily_assert_msg(bool statement, const char *location,
+			  const char *format_string, ...)
+{
+	va_list args;
+	va_start(args, format_string);
+	// _lily_assert_msg may long jump, so it takes calls va_end(args) for you
+	_lily_assert_msg(statement, location, format_string, args);
+}
+
+
+void _lily_assert_true(const char *statement, bool value, const char *location)
+{
+	lily_assert_msg(value, location,
+			"%s is not true",
+			statement);
+}
+
+
+void _lily_assert_false(const char *statement, bool value, const char *location)
+{
+	lily_assert_msg(!value, location,
+			"%s is not false",
+			statement);
+}
+
+
+void _lily_assert_not_null(const char *name, void *ptr, const char *location)
+{
+	lily_assert_msg(ptr != NULL, location,
+			"%s is NULL",
+			name);
+}
+
+
+void _lily_assert_null(const char *name, void *ptr, const char *location)
+{
+	lily_assert_msg(ptr == NULL, location,
+			"%s (%p) is not NULL",
+			name, ptr);
+}
+
+
+void _lily_assert_ptr_equal(const char *name_a, const char *name_b,
+				 void *a, void *b, const char *location)
+{
+	lily_assert_msg(a == b, location,
+			"%s (%p) is not equal to %s (%p)",
+			name_a, a, name_b, b);
+}
+
+
+void _lily_assert_ptr_not_equal(const char *name_a, const char *name_b,
+				 void *a, void *b, const char *location)
+{
+	lily_assert_msg(a != b, location,
+			"%s (%p) is equal to %s",
+			name_a, a, name_b);
+}
+
+
+void _lily_assert_int_equal(const char *name_a, const char *name_b,
+				 intmax_t a, intmax_t b, const char *location)
+{
+	lily_assert_msg(a == b, location,
+			"%s (%d) is not equal to %s (%d)",
+			name_a, a, name_b, b);
+}
+
+
+void _lily_assert_int_not_equal(const char *name_a, const char *name_b,
+				 intmax_t a, intmax_t b, const char *location)
+{
+	lily_assert_msg(a != b, location,
+			"%s (%d) is equal to %s",
+			name_a, a, name_b);
+}
+
+
+void _lily_assert_float_equal(const char *name_a, const char *name_b,
+					double a, double b, double epsilon, const char *location)
+{
+	lily_assert_msg(fabs(a - b) <= epsilon, location,
+			"%s (%f) is not equal to %s (%f) (epsilon: %f)",
+			name_a, a, name_b, b, epsilon);
+}
+
+
+void _lily_assert_float_not_equal(const char *name_a, const char *name_b,
+				  double a, double b, double epsilon, const char *location)
+{
+	lily_assert_msg(fabs(a - b) > epsilon, location,
+			"%s (%f) is equal to %s (%f) (epsilon: %f)",
+			name_a, a, name_b, b, epsilon);
+}
+
+
+void _lily_assert_string_equal(const char *name_a, const char *name_b,
+					 char *a, char *b, const char *location)
+{
+	lily_assert_msg(strcmp(a, b) == 0, location,
+			"%s ('%s') is not equal to %s ('%s')",
+			name_a, a, name_b, b);
+}
+
+
+void _lily_assert_string_not_equal(const char *name_a, const char *name_b,
+					char *a, char *b, const char *location)
+{
+	lily_assert_msg(strcmp(a, b) != 0, location,
+			"%s ('%s') is equal to %s",
+			name_a, a, name_b);
+}
+
+
+void _lily_assert_memory_equal(const char *name_a, const char *name_b,
+					 void *a, void *b, size_t size, const char *location)
+{
+	lily_assert_msg(memcmp(a, b, size) == 0, location,
+			"%s and %s contain different data", name_a, name_b);
+}
+
+
+void _lily_assert_memory_not_equal(const char *name_a, const char *name_b,
+					void *a, void *b, size_t size, const char *location)
+{
+	lily_assert_msg(memcmp(a, b, size) == 0, location,
+			"%s contains the same data s %s", name_a, name_b);
+}
+
+
+/* ======== MOCKS ======== */
+
+lily_queue_t* lily_queue_create()
+{
+	const size_t size = 256 * sizeof(uint8_t);
+
+	lily_queue_t *q = malloc(sizeof(lily_queue_t));
+	q->buf_size = size;
+	q->buf = malloc(size);
+	q->front = q->buf;
+	q->back = q->front;
+
+	return q;
+}
+
+
+void lily_queue_destroy(lily_queue_t *q)
+{
+	free(q->buf);
+	free(q);
+}
+
+
+void _lily_enqueue(lily_queue_t *q, size_t size, uint8_t *data)
+{
+	size_t used = q->back - q->buf;
+	size_t remaining = q->buf_size - used;
+
+	if (remaining < size) {
+		/* re-allocate bigger buffer */
+		size_t size_new = 2 * q->buf_size;
+		uint8_t *buf_new = realloc(q->buf, size_new);
+		if (buf_new == NULL) {
+	 fprintf(stderr, "failed to allocated %lu bytes for queue %p!\n",
+		 size_new, q);
+	 return;
+		}
+		q->buf = buf_new;
+	}
+
+	memcpy(q->back, data, size);
+	q->back += size;
+}
+
+
+void _lily_dequeue(lily_queue_t *q, size_t size, uint8_t *ptr)
+{
+	size_t dist = q->back - q->front;
+	if (dist < size) {
+		fprintf(stderr, "attempted to read %lu bytes out of queue %p, "
+			"which has %lu bytes presently queued\n", size, q, dist);
+		return;
+	}
+
+	memcpy(ptr, q->front, size);
+	q->front += size;
+}
+
+
+lily_mock_t * lily_mock_create()
+{
+	lily_mock_t *m = malloc(sizeof(lily_mock_t));
+	m->n_calls = 0;
+	m->arguments = lily_queue_create();
+	m->values = lily_queue_create();
+	return m;
+}
+
+void lily_mock_destroy(lily_mock_t *m)
+{
+	lily_queue_destroy(m->arguments);
+	lily_queue_destroy(m->values);
+	free(m);
+}
+
+void lily_mock_use(lily_mock_t **m)
+{
+	if (*m != NULL) lily_mock_destroy(*m);
+	*m = lily_mock_create();
+}
+
+void _lily_mock_call(lily_mock_t *m, struct lily_mock_arg_t *args, size_t n_args)
+{
+	m->n_calls += 1;
+
+	for (int i=0; i<n_args; i++) {
+		_lily_enqueue(m->arguments, args[i].size, args[i].var);
+	}
+}
+
+void _lily_get_call(lily_mock_t *m,
+			 struct lily_mock_arg_t *args,
+			 size_t n_args,
+			 unsigned int call_num)
+{
+	size_t stride = 0;
+	for (int i=0; i<n_args; i++) {
+		stride += args[i].size;
+	}
+
+	m->arguments->front = m->arguments->buf + (call_num * stride);
+	for (int i=0; i<n_args; i++) {
+		_lily_dequeue(m->arguments, args[i].size, args[i].var);
+	}
+}
diff --git a/src/test/lily-test.h b/src/test/lily-test.h
new file mode 100644
index 0000000..b5f380c
--- /dev/null
+++ b/src/test/lily-test.h
@@ -0,0 +1,263 @@
+/****************************************************************
+ *
+ * ======== lily-test ========
+ *
+ * a midsize C unit testing library
+ * copyright (c) 2022 kate swanson (sanine)
+ *
+ * This is anti-capitalist software, released for free use by individuals and
+ * organizations that do not operate by capitalist principles.
+ *
+ * Permission is hereby granted, free of charge, to any person or
+ * organization (the "User") obtaining a copy of this software and associated
+ * documentation files (the "Software"), to use, copy, modify, merge,
+ * distribute, and/or sell copies of the Software, subject to the following conditions:
+ *
+ * 1. The above copyright notice and this permission notice shall be included
+ *    in all copies or modified versions of the Software.
+ *
+ * 2. The User is one of the following:
+ *    a. An individual person, laboring for themselves
+ *    b. A non-profit organization
+ *    c. An educational institution
+ *    d. An organization that seeks shared profit for all of its members, and
+ *       allows non-members to set the cost of their labor
+ *
+ * 3. If the User is an organization with owners, then all owners are workers
+ *    and all workers are owners with equal equity and/or equal vote.
+ *
+ * 4. If the User is an organization, then the User is not law enforcement or
+ *    military, or working for or under either.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT EXPRESS OR IMPLIED WARRANTY OF
+ * ANY KIND, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://anticapitalist.software/
+ * https://sanine.net
+ *
+ ****************************************************************/
+
+
+#ifndef LILY_TEST_H
+#define LILY_TEST_H
+
+#define LILY_VERSION_MAJOR 1
+#define LILY_VERSION_MINOR 0
+#define LILY_VERSION_PATCH 0
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <setjmp.h>
+
+#define STR_IMP(x) #x
+#define STR(x) STR_IMP(x)
+/* define SOURCE_PATH_SIZE to strip away the
+	leading parts of the full compilation path */
+#ifndef SOURCE_PATH_SIZE
+#define LILY_LOCATION (__FILE__ ":" STR(__LINE__))
+#else
+#define LILY_LOCATION ((__FILE__ ":" STR(__LINE__)) + SOURCE_PATH_SIZE)
+#endif
+
+/** a few nasty globals that make everything clean for the end user */
+struct lily_globals_t {
+	jmp_buf env;
+	size_t error_msg_len;
+	char *error_msg;
+	const char *error_location;
+};
+extern struct lily_globals_t _lily_globals;
+
+typedef void (*lily_test_t)(void);
+
+/** run a single test */
+#define lily_run_test(test) _lily_run_test(#test, test)
+void _lily_run_test(const char *name, lily_test_t test);
+
+/** run a suite */
+#define lily_run_suite(suite) _lily_run_suite(#suite, suite)
+void _lily_run_suite(const char *name, lily_test_t suite);
+
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * assertions
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+/** basic assertion function, mostly used by the other assertions */
+void lily_assert_msg(bool statement, const char *location,
+			  const char *format_string, ...);
+
+#define lily_assert_true(statement) _lily_assert_true(#statement, statement, LILY_LOCATION)
+void _lily_assert_true(const char *statement, bool value, const char *location);
+
+
+#define lily_assert_false(statement) _lily_assert_false(#statement, statement, LILY_LOCATION)
+void _lily_assert_false(const char *statement, bool value, const char *location);
+
+
+#define lily_assert_not_null(ptr) _lily_assert_not_null(#ptr, ptr, LILY_LOCATION)
+void _lily_assert_not_null(const char *name, void *ptr, const char *location);
+
+
+#define lily_assert_null(ptr) _lily_assert_null(#ptr, ptr, LILY_LOCATION)
+void _lily_assert_null(const char *name, void *ptr, const char *location);
+
+
+#define lily_assert_ptr_equal(a, b) _lily_assert_ptr_equal(#a, #b, a, b, LILY_LOCATION)
+void _lily_assert_ptr_equal(const char *name_a, const char *name_b,
+				 void *a, void *b, const char *location);
+
+
+#define lily_assert_ptr_not_equal(a, b) _lily_assert_ptr_not_equal(#a, #b, a, b, LILY_LOCATION)
+void _lily_assert_ptr_not_equal(const char *name_a, const char *name_b,
+				void *a, void *b, const char *location);
+
+
+#define lily_assert_int_equal(a, b) _lily_assert_int_equal(#a, #b, a, b, LILY_LOCATION)
+void _lily_assert_int_equal(const char *name_a, const char *name_b,
+				 intmax_t a, intmax_t b, const char *location);
+
+
+#define lily_assert_int_not_equal(a, b) _lily_assert_int_not_equal(#a, #b, a, b, LILY_LOCATION)
+void _lily_assert_int_not_equal(const char *name_a, const char *name_b,
+				intmax_t a, intmax_t b, const char *location);
+
+
+#define lily_assert_float_equal(a, b, epsilon)				\
+	_lily_assert_float_equal(#a, #b, a, b, epsilon, LILY_LOCATION)
+void _lily_assert_float_equal(const char *name_a, const char *name_b,
+					double a, double b, double epsilon, const char *location);
+
+
+#define lily_assert_float_not_equal(a, b, epsilon)			\
+	_lily_assert_float_not_equal(#a, #b, a, b, epsilon, LILY_LOCATION)
+void _lily_assert_float_not_equal(const char *name_a, const char *name_b,
+				  double a, double b, double epsilon, const char *location);
+
+
+#define lily_assert_string_equal(a, b) _lily_assert_string_equal(#a, #b, a, b, LILY_LOCATION)
+void _lily_assert_string_equal(const char *name_a, const char *name_b,
+					 char *a, char *b, const char *location);
+
+
+#define lily_assert_string_not_equal(a, b) _lily_assert_string_not_equal(#a, #b, a, b, LILY_LOCATION)
+void _lily_assert_string_not_equal(const char *name_a, const char *name_b,
+					char *a, char *b, const char *location);
+
+
+#define lily_assert_memory_equal(a, b, size)			\
+	_lily_assert_memory_equal(#a, #b, a, b, size, LILY_LOCATION)
+void _lily_assert_memory_equal(const char *name_a, const char *name_b,
+					 void *a, void *b, size_t size, const char *location);
+
+
+#define lily_assert_memory_not_equal(a, b, size)			\
+	_lily_assert_memory_not_equal(#a, #b, a, b, size, LILY_LOCATION)
+void _lily_assert_memory_not_equal(const char *name_a, const char *name_b,
+					void *a, void *b, size_t size, const char *location);
+
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * mocks
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+
+/** queue structure capable of containing arbitrary data */
+typedef struct lily_queue_t {
+	size_t buf_size;
+	uint8_t *buf;
+	uint8_t *front, *back;
+} lily_queue_t;
+
+
+/** create a queue */
+lily_queue_t* lily_queue_create();
+
+/** destroy a queue */
+void lily_queue_destroy(lily_queue_t *q);
+
+
+/** enqueue a value
+ *
+ * q - the queue to append to
+ * type - the type of the value to append
+ * value - the value to append
+ */
+#define lily_enqueue(q, type, value)				\
+	do {								\
+		type _var = value;					\
+		_lily_enqueue(q, sizeof(type), (uint8_t*)(&_var));	\
+	} while(0)
+void _lily_enqueue(lily_queue_t *q, size_t size, uint8_t *data);
+
+
+/** pop a value from the queue
+ *
+ * q - the queue to pop from
+ * type - the type of the value to pop
+ * ptr - the location to store the popped value
+ */
+#define lily_dequeue(q, type, ptr)			\
+	_lily_dequeue(q, sizeof(type), (uint8_t*) ptr)
+void _lily_dequeue(lily_queue_t *q, size_t size, uint8_t *ptr);
+
+
+struct lily_mock_arg_t {
+	size_t size;
+	void *var;
+};
+
+#define LILY_NARGS(args) (sizeof(args)/sizeof(struct lily_mock_arg_t))
+
+/** structure to store data for mock functions */
+typedef struct lily_mock_t {
+	unsigned int n_calls;
+	lily_queue_t *arguments;
+	lily_queue_t *values;
+} lily_mock_t;
+
+/** setup mock function storage */
+lily_mock_t * lily_mock_create();
+/** tear down mock function storage */
+void lily_mock_destroy(lily_mock_t *m);
+/** automatically re-create mock function storage */
+void lily_mock_use(lily_mock_t **m);
+
+/** store a call to a mock function */
+#define lily_mock_store_call(m, args)	\
+	_lily_mock_call(m, args, LILY_NARGS(args))
+/* lily_mock_call is deprecated!! do not use it in new programs */
+#define lily_mock_call(m, args)			\
+	_lily_mock_call(m, args, LILY_NARGS(args))
+void _lily_mock_call(lily_mock_t *m, struct lily_mock_arg_t *args, size_t n_args);
+
+/** retrieve a call to a mock function */
+#define lily_mock_get_call(m, args, call_num)	\
+	_lily_get_call(m, args, LILY_NARGS(args), call_num)
+/* lily_get_call is deprecated!! do not use it in new programs */
+#define lily_get_call(m, args, call_num)		\
+	_lily_get_call(m, args, LILY_NARGS(args), call_num)
+void _lily_get_call(lily_mock_t *m,
+			 struct lily_mock_arg_t *args,
+			 size_t n_args,
+			 unsigned int call_num);
+
+/** store a value in a mock structure */
+#define lily_store_value(m, type, value)	\
+	lily_enqueue(m->values, type, value)
+/** retrieve a value from a mock structure */
+#define lily_get_value(m, type, ptr)		\
+	lily_dequeue(m->values, type, ptr)
+
+#endif
diff --git a/src/test/test.c b/src/test/test.c
new file mode 100644
index 0000000..c97f325
--- /dev/null
+++ b/src/test/test.c
@@ -0,0 +1,7 @@
+#include "test.h"
+
+int main()
+{
+	RUN_TESTS();
+	return 0;
+}
diff --git a/src/test/test.h b/src/test/test.h
new file mode 100644
index 0000000..17731b9
--- /dev/null
+++ b/src/test/test.h
@@ -0,0 +1,15 @@
+#ifndef KALMIA_TEST_H
+#define KALMIA_TEST_H
+
+#include "lily-test.h"
+
+
+void suite_transform();
+
+
+#define RUN_TESTS() \
+	do { \
+		lily_run_suite(suite_transform); \
+	} while (0)
+
+#endif
diff --git a/src/transform.c b/src/transform.c
new file mode 100644
index 0000000..7c50a5e
--- /dev/null
+++ b/src/transform.c
@@ -0,0 +1,23 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include <kalmia.h>
+#include <ezxml.h>
+#include "transform.h"
+
+
+int kai_parse_matrix(ka_matrix_t *m, ezxml_t tag)
+{
+	if (strcmp("matrix", ezxml_name(tag)) != 0)
+		return -1;
+	
+	char *str = ezxml_txt(tag);
+	char *end;
+	int i;
+	for (i=0; i<16; i++) {
+		(*m)[i] = strtod(str, &end);
+		str = end;
+	}
+	
+	return 0;
+}
diff --git a/src/transform.h b/src/transform.h
new file mode 100644
index 0000000..ef8b3e0
--- /dev/null
+++ b/src/transform.h
@@ -0,0 +1,6 @@
+#include <kalmia.h>
+#include <ezxml.h>
+
+
+/* parse a <matrix> tag into a ka_matrix_t */
+int kai_parse_matrix(ka_matrix_t *m, ezxml_t tag);
diff --git a/src/transform.test.c b/src/transform.test.c
new file mode 100644
index 0000000..e9982f6
--- /dev/null
+++ b/src/transform.test.c
@@ -0,0 +1,71 @@
+#include <string.h>
+#include <kalmia.h>
+#include "test/test.h"
+#include "transform.h"
+
+
+void parse_matrix_fail_nonmatrix();
+void parse_identity();
+
+
+void suite_transform()
+{
+	lily_run_test(parse_matrix_fail_nonmatrix);
+	lily_run_test(parse_identity);
+}
+
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void parse_matrix_fail_nonmatrix()
+{
+	char str[128];
+	strncpy(str, "<nonmatrix></nonmatrix>", 128);
+	ezxml_t tag = ezxml_parse_str(str, strlen(str));
+
+	ka_matrix_t mat;
+	int rc = kai_parse_matrix(&mat, tag);
+	lily_assert_true(rc != 0);
+
+	ezxml_free(tag);
+}
+
+
+void parse_identity()
+{
+	char str[512];
+	strncpy(
+		str, 
+		"<matrix>\n"
+		"	1 0 0 0\n"
+		"	0 1 0 0\n"
+		"	0 0 1 0\n"
+		"	0 0 0 1\n"
+		"</matrix>",
+		512
+	);
+	ezxml_t tag = ezxml_parse_str(str, strlen(str));
+
+	ka_matrix_t mat;
+	mat[0] = 100;
+	int rc = kai_parse_matrix(&mat, tag);
+	lily_assert_true(rc == 0);
+	ezxml_free(tag);
+
+	lily_assert_float_equal(mat[0], 1.0f, 1e-3);
+	lily_assert_float_equal(mat[1], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[2], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[3], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[4], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[5], 1.0f, 1e-3);
+	lily_assert_float_equal(mat[6], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[7], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[8], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[9], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[10], 1.0f, 1e-3);
+	lily_assert_float_equal(mat[11], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[12], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[13], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[14], 0.0f, 1e-3);
+	lily_assert_float_equal(mat[15], 1.0f, 1e-3);
+}