mdoc.internal.markdown.mdocParserExtension.scala Maven / Gradle / Ivy
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package mdoc.internal.markdown
import com.vladsch.flexmark.Extension
import com.vladsch.flexmark.ast
import com.vladsch.flexmark.parser.LinkRefProcessor
import com.vladsch.flexmark.parser.LinkRefProcessorFactory
import com.vladsch.flexmark.parser.Parser
import com.vladsch.flexmark.util.options.DataHolder
import com.vladsch.flexmark.util.options.MutableDataHolder
import com.vladsch.flexmark.util.sequence.BasedSequence
import com.vladsch.flexmark.util.sequence.PrefixedSubSequence
import mdoc.internal.cli.Context
class MdocParserExtension(context: Context) extends Parser.ParserExtension {
class SiteVariableInjector(site: Map[String, String], document: ast.Document)
extends LinkRefProcessor {
/**
* Creates a text node with the value of a site variable.
*
* Using `PrefixedSubSequence` and then removing suffix is the only way I found to simulate
* `replace`. Converting from `String` to `BasedSequence` via `stringToCharSequence` does not
* work because Flexmark's `Text` only uses the start and end offsets and does not do an
* in-place replacement of the contents of the returned sequence. These start and end offsets
* select from the original text, not the modified value that we wanted to insert.
* Creating a custom node extending `ContentNode` or `CustomNode` did not help either.
*/
override def createNode(nodeChars: BasedSequence): ast.Node = {
nodeChars.toString match {
case VariableInjectionPattern(key) =>
val value = site.getOrElse(key, sys.error(s"Missing '$key' site variable."))
new ast.Text(PrefixedSubSequence.of(value, nodeChars).removeSuffix(nodeChars))
case _ =>
sys.error("Flexmark matched a variable injection which is not of the expected shape.")
}
}
private final val totalLength = document.getTextLength
private final val VariableInjectionPattern = "!\\[([^\\]\\[]*)\\]".r
override def isMatch(nodeChars: BasedSequence): Boolean = {
val matches = nodeChars.toString.matches(VariableInjectionPattern.regex)
val startNext = nodeChars.getEndOffset
val endNext = startNext + 1
// As bracket nesting level is 0, we need to check that the following char does not start with `[`
matches && (
startNext == totalLength ||
!document.getChars.baseSubSequence(startNext, endNext).startsWith("[")
)
}
override def adjustInlineText(doc: ast.Document, node: ast.Node): BasedSequence = node.getChars
override def getBracketNestingLevel: Int = 0
override def getWantExclamationPrefix: Boolean = true
override def updateNodeElements(document: ast.Document, node: ast.Node): Unit = ()
override def allowDelimiters(chars: BasedSequence, doc: ast.Document, node: ast.Node): Boolean =
true
}
class SiteVariableInjectorFactory extends LinkRefProcessorFactory {
override def getBracketNestingLevel(options: DataHolder): Int = 0
override def getWantExclamationPrefix(options: DataHolder): Boolean = true
override def create(document: ast.Document): LinkRefProcessor =
new SiteVariableInjector(context.settings.site, document)
}
override def extend(parserBuilder: Parser.Builder): Unit = {
parserBuilder.linkRefProcessorFactory(new SiteVariableInjectorFactory)
parserBuilder.postProcessorFactory(
new MdocPostProcessor.Factory(context)
)
}
override def parserOptions(options: MutableDataHolder): Unit = ()
}
object MdocParserExtension {
def create(context: Context): Extension = {
new MdocParserExtension(context)
}
}