Chez-XML λ-0.2

Introduction

[中文版本]

A lite non-standard xml parser in Chez Scheme.

• Parse XML into scheme tree structure
• Element will be convert into ((name . attr-alist) . child-list)
• Toggle between space-preserving and space-ignoring modes.
• Declaration, xml head, and DOCTYPE declarations are silently skipped at any position.
• Supports XML comments inside open-tag bodies.

Installation

(Chez Scheme (v10.4.1) is required)

chez-xml is a single-file library, ./src/xml.sls is the source code. Load it directly or compile to xml.so for faster loading.

Basic steps

By following steps, you can easily compile and run the test case.

git clone https://github.com/Yunoinsky/chez-xml # clone this repository
cd chez-xml
echo '(compile-file "src/xml.sls")' | scheme -q  # optional: pre-compile
scheme --script ./test/test.ss

Global installation

By copying xml.sls to the target project, we can use chez-xml in other projects. You can also choose to install it globally as a pre-compiled library. Here is one way to do this.

1. Compile: echo '(compile-file "src/xml.sls")' | scheme -q
2. Create lib directory: ~/Library/chezscheme/.
3. Copy xml.so to this directory.
4. Append /Library/chezscheme/ to ~CHEZSCHEMELIBDIRS.
5. Then, (import (xml)) works in any project.

Basic Usage

Take an excerpt from the API of Raysan’s outstanding project - raylib as an example.

<?xml version="1.0" encoding="Windows-1252" ?>

<!-- ./test/test_raylibapi.xml -->
<!-- https://raw.githubusercontent.com/raysan5/raylib/refs/heads/master/tools/rlparser/output/raylib_api.xml -->

<raylibAPI>
  <Defines count="4">
    <Define name="PI" type="FLOAT" value="3.14159265358979323846" desc="" />
    <Define name="DEG2RAD" type="FLOAT_MATH" value="(PI/180.0f)" desc="" />
    <Define name="RED" type="COLOR" value="CLITERAL(Color){ 200, 200, 200, 255 }" desc="Light Gray" />
    <Define name="BLUE" type="COLOR" value="CLITERAL(Color){ 0, 121, 241, 255 }" desc="Blue" />
  </Defines>
  <Structs count="4">
    <Struct name="Vector2" fieldCount="2" desc="Vector2, 2 components">
      <Field type="float" name="x" desc="Vector x component" />
      <Field type="float" name="y" desc="Vector y component" />
    </Struct>
    <Struct name="Vector3" fieldCount="3" desc="Vector3, 3 components">
      <Field type="float" name="x" desc="Vector x component" />
      <Field type="float" name="y" desc="Vector y component" />
      <Field type="float" name="z" desc="Vector z component" />
    </Struct>
    <Struct name="Color" fieldCount="4" desc="Color, 4 components, R8G8B8A8 (32bit)">
      <Field type="unsigned char" name="r" desc="Color red value" />
      <Field type="unsigned char" name="g" desc="Color green value" />
      <Field type="unsigned char" name="b" desc="Color blue value" />
      <Field type="unsigned char" name="a" desc="Color alpha value" />
    </Struct>
    <Struct name="Rectangle" fieldCount="4" desc="Rectangle, 4 components">
      <Field type="float" name="x" desc="Rectangle top-left corner position x" />
      <Field type="float" name="y" desc="Rectangle top-left corner position y" />
      <Field type="float" name="width" desc="Rectangle width" />
      <Field type="float" name="height" desc="Rectangle height" />
    </Struct>
  </Structs>
  <Functions count="2">
    <Function name="InitWindow" retType="void" paramCount="3" desc="Initialize window and OpenGL context">
      <Param type="int" name="width" desc="" />
      <Param type="int" name="height" desc="" />
      <Param type="const char *" name="title" desc="" />
    </Function>
    <Function name="IsWindowReady" retType="bool" paramCount="0" desc="Check if window has been initialized successfully">
    </Function>
  </Functions>
</raylibAPI>  

Load and import library

(load "./src/xml.sls") ;; this line can be commented
                      ;; out if installed globally
(import (xml))

Lite XML Reader

(xml-load text-port preserve-blank)

Load xml-data from a text-port, return a scheme tree. If preserve-blank is #t, all of the blank chars will be preserved and parsed as strings, or they will be ignored.

(define fp (open-input-file "./test/test_raylibapi.xml"))
(define data (xml-load fp #f))
(pretty-print data)

Basic data structure

(xml-get-name node)

Get the name of xml node.

(xml-get-attrs node)

Get the attrs alist of xml node.

(xml-get-children node)

Get the children’s list of xml node.

(define funcs-data (caddr (xml-get-children data)))

(pretty-print (xml-get-name funcs-data))
(pretty-print (xml-get-attrs funcs-data))

(define func1-data (car (xml-get-children funcs-data)))
(pretty-print (xml-get-name func1-data))
(pretty-print (xml-get-attrs func1-data))
(pretty-print (xml-get-children func1-data))