Chez-XML λ-0.1

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.
• Can only ignore the delaration and xml head for now.
• DTD are currently not supported.
• Comment inside label cannot be parse correctly

Installation

(Chez Scheme (v9.5.8) is required)

xml-toml is a single-file library, ./src/xml.sls is the source code, ./src/xml.so is its compiled file. Each of them is enough to use chez-xml.

Basic steps

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

git clone https://github.com/Yunoinsky/xml-toml # clone this repository
cd chez-xml
scheme --script ./test/test.ss

Global installation

By copying xml.sls or xml.so to the corresponding project, we can use chez-xml in other projects. You can also choose to install it globally. Here is one way to do this.

1. Create lib directory: ~~/Library/chezscheme/~.
2. Copy xml.so or xml.sls to this directory.
3. append ~~/Library/chezscheme/~ to the environment variable CHEZSCHEMELIBDIRS.
4. Then, we can use (import (xml)) to import this library directly.

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/master/parser/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.so") ;; 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))