interpreter settings

README.md

@@ -12,18 +12,9 @@ sxml-loader
 
 Scheme XML loader for webpack.
 
-**NOTE**:
-At the moment, the _sxml-loader_ only works with
-[Chicken Scheme](http://call-cc.org/) and its
-[sxml-serializer](http://wiki.call-cc.org/eggref/5/sxml-serializer)
-egg, so you need to install them in order to use the _sxml-loader_.
-
 Usage
 -----
-**SXML**:
-```scm
-'(h1 "Hello")
-```
+_See the full example in the [example](example) directory._
 
 **webpack.config.js**:
 ```js
@@ -41,6 +32,29 @@ module.exports = {
 }
 ```
 
+By default SXML will be processed by _Chicken Scheme_
+with _sxml-serializer_ egg. You can use a different interpreter
+by setting the loader options.
+
+GNU Guile example:
+```js
+// ...
+use: [
+  'html-loader',
+  {
+    loader: 'sxml-loader',
+    options: {
+      interpreter: 'guile',
+      flags: ['-c'], // "eval" flag (in Guile case "-c") should be last.
+
+      // SXML_LOADER_CONTENT will be replaced with processing SXML markup.
+      expr: '(use-modules (sxml simple))(sxml->xml SXML_LOADER_CONTENT)',
+    },
+  },
+],
+// ...
+```
+
 License
 -------
 GPLv3 or later. See full text in the [COPYING](COPYING) file

src/loader.js

@@ -1,17 +1,64 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 // Copyright 2022 Ivan Polyakov
 const { spawn } = require('child_process');
+const { validate } = require('schema-utils');
+
+const schema = {
+    type: 'object',
+    properties: {
+        interpreter: {
+            type: 'string',
+            default: 'chicken-csi',
+        },
+        flags: {
+            type: 'array',
+            default: ['-e'],
+        },
+        expr: {
+            type: 'string',
+            default: '(import sxml-serializer)(display (serialize-sxml SXML_LOADER_CONTENT))',
+        },
+    },
+};
 
 module.exports = function(content, map, meta) {
-    const cb = this.async();
-    const expr = `(import sxml-serializer)(display (serialize-sxml ${content}))`;
-    const scheme = spawn('chicken-csi', ['-e', expr]);
+    const options = this.getOptions();
+    validate(schema, options, {
+        name: 'SXML Loader',
+        baseDataPath: 'options',
+    });
+
+    let interpreter = schema.properties.interpreter.default;
+    if (options.interpreter)
+        interpreter = options.interpreter;
+
+    let flags = schema.properties.flags.default;
+    if (options.flags)
+        flags = options.flags;
+
+    let expr = schema.properties.expr.default;
+    if (options.expr)
+        expr = options.expr;
+    expr = expr.replace('SXML_LOADER_CONTENT', content);
+    flags.push(expr);
 
-    scheme.stdout.on('data', data => {
+    const cb = this.async();
+    runScheme(interpreter, flags).then(data => {
         cb(null, data, map, meta);
+    }).catch(err => {
+        console.error(err);
     });
+}
+
+function runScheme(interpreter, flags) {
+    return new Promise((resolve, reject) => {
+        const scheme = spawn(interpreter, flags);
 
-    scheme.stderr.on('data', data => {
-        console.error(data);
+        scheme.stdout.on('data', (data) => {
+            resolve(data);
+        });
+        scheme.stderr.on('data', (data) => {
+            reject(data.toString());
+        });
     });
 }