Finish substitution implementation

5 files changed, 138 insertions, 99 deletions

diff --git a/src/parser/conversion/block.rs b/src/parser/conversion/block.rs
index 8659dcd..0c313f6 100644
--- a/src/parser/conversion/block.rs
+++ b/src/parser/conversion/block.rs
@@ -111,25 +111,22 @@ fn convert_replace(pair: Pair<Rule>) -> Result<Vec<c::TextOrInlineElement>, Erro
 fn convert_image<I>(pair: Pair<Rule>) -> Result<I, Error> where I: Element + ExtraAttributes<a::Image> {
 	let mut pairs = pair.into_inner();
 	let mut image = I::with_extra(a::Image::new(
-		pairs.next().unwrap().parse()?,  // line
+		pairs.next().unwrap().as_str().trim().parse()?,  // line
 	));
-	if let Some(opt_block) = pairs.next() {  // image_opt_block
-		let options = opt_block.into_inner();
-		for opt in options {
-			let mut opt_iter = opt.into_inner();
-			let opt_name = opt_iter.next().unwrap();
-			let opt_val = opt_iter.next().unwrap();
-			match opt_name.as_str() {
-				"class"  => image.classes_mut().push(opt_val.as_str().to_owned()),
-				"name"   => image.names_mut().push(opt_val.as_str().into()),
-				"alt"    => image.extra_mut().alt    = Some(opt_val.as_str().to_owned()),
-				"height" => image.extra_mut().height = Some(opt_val.parse()?),
-				"width"  => image.extra_mut().width  = Some(opt_val.parse()?),
-				"scale"  => image.extra_mut().scale  = Some(parse_scale(&opt_val)?),
-				"align"  => image.extra_mut().align  = Some(opt_val.parse()?),
-				"target" => image.extra_mut().target = Some(opt_val.parse()?),
-				name => bail!("Unknown Image option {}", name),
-			}
+	for opt in pairs {
+		let mut opt_iter = opt.into_inner();
+		let opt_name = opt_iter.next().unwrap();
+		let opt_val = opt_iter.next().unwrap();
+		match opt_name.as_str() {
+			"class"  => image.classes_mut().push(opt_val.as_str().to_owned()),
+			"name"   => image.names_mut().push(opt_val.as_str().into()),
+			"alt"    => image.extra_mut().alt    = Some(opt_val.as_str().to_owned()),
+			"height" => image.extra_mut().height = Some(opt_val.parse()?),
+			"width"  => image.extra_mut().width  = Some(opt_val.parse()?),
+			"scale"  => image.extra_mut().scale  = Some(parse_scale(&opt_val)?),
+			"align"  => image.extra_mut().align  = Some(opt_val.parse()?),
+			"target" => image.extra_mut().target = Some(opt_val.parse()?),
+			name => bail!("Unknown Image option {}", name),
 		}
 	}
 	Ok(image)
diff --git a/src/parser/simplify.rs b/src/parser/simplify.rs
index ab79343..cc169ee 100644
--- a/src/parser/simplify.rs
+++ b/src/parser/simplify.rs
@@ -53,7 +53,7 @@ impl NamedTargetType {
 
 #[derive(Clone, Debug)]
 struct Substitution {
-	content: e::ImageInline,
+	content: Vec<c::TextOrInlineElement>,
 	/// If true and the sibling before the reference is a text node,
 	/// the text node gets right-trimmed. 
 	ltrim: bool,
@@ -94,7 +94,7 @@ impl TargetsCollected {
 
 trait ResolvableRefs {
 	fn populate_targets(&self, refs: &mut TargetsCollected);
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self;
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> where Self: Sized;
 }
 
 pub fn resolve_references(mut doc: Document) -> Document {
@@ -102,7 +102,7 @@ pub fn resolve_references(mut doc: Document) -> Document {
 	for c in doc.children() {
 		c.populate_targets(&mut references);
 	}
-	let new: Vec<_> = doc.children_mut().drain(..).map(|c| c.resolve_refs(&references)).collect();
+	let new: Vec<_> = doc.children_mut().drain(..).flat_map(|c| c.resolve_refs(&references)).collect();
 	Document::with_children(new)
 }
 
@@ -113,7 +113,7 @@ fn sub_pop<P, C>(parent: &P, refs: &mut TargetsCollected) where P: HasChildren<C
 }
 
 fn sub_res<P, C>(mut parent: P, refs: &TargetsCollected) -> P where P: e::Element + HasChildren<C>, C: ResolvableRefs {
-	let new: Vec<_> = parent.children_mut().drain(..).map(|c| c.resolve_refs(refs)).collect();
+	let new: Vec<_> = parent.children_mut().drain(..).flat_map(|c| c.resolve_refs(refs)).collect();
 	parent.children_mut().extend(new);
 	parent
 }
@@ -141,15 +141,15 @@ impl ResolvableRefs for c::StructuralSubElement {
 			SubStructure(e) => e.populate_targets(refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::StructuralSubElement::*;
-		match self {
+		vec![match self {
 			Title(e)        => sub_res(*e, refs).into(),
 			Subtitle(e)     => sub_res(*e, refs).into(),
 			Decoration(e)   => sub_res(*e, refs).into(),
 			Docinfo(e)      => sub_res(*e, refs).into(),
-			SubStructure(e) => e.resolve_refs(refs).into(),
-		}
+			SubStructure(e) => return e.resolve_refs(refs).drain(..).map(Into::into).collect(),
+		}]
 	}
 }
 
@@ -164,15 +164,15 @@ impl ResolvableRefs for c::SubStructure {
 			BodyElement(e) => e.populate_targets(refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubStructure::*;
-		match self {
+		vec![match self {
 			Topic(e) => sub_res(*e, refs).into(),
 			Sidebar(e) => sub_res(*e, refs).into(),
 			Transition(e) => Transition(e),
 			Section(e) => sub_res(*e, refs).into(),
-			BodyElement(e) => e.resolve_refs(refs).into(),
-		}
+			BodyElement(e) => return e.resolve_refs(refs).drain(..).map(Into::into).collect(),
+		}]
 	}
 }
 
@@ -186,13 +186,8 @@ impl ResolvableRefs for c::BodyElement {
 			MathBlock(_) => {},
 			Rubric(e) => sub_pop(&**e, refs),
 			SubstitutionDefinition(e) => {
-				let subst_content = if let [c::TextOrInlineElement::ImageInline(content)] = &e.children()[..] {
-					content.as_ref()
-				} else {
-					panic!("Unexpected substitution contents.")
-				};
 				let subst = Substitution {
-					content: subst_content.clone(),
+					content: e.children().clone(),
 					ltrim: e.extra().ltrim,
 					rtrim: e.extra().rtrim
 				};
@@ -246,15 +241,15 @@ impl ResolvableRefs for c::BodyElement {
 			Table(e) => sub_pop(&**e, refs)
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::BodyElement::*;
-		match self {
+		vec![match self {
 			Paragraph(e) => sub_res(*e, refs).into(),
 			LiteralBlock(e) => sub_res(*e, refs).into(),
 			DoctestBlock(e) => sub_res(*e, refs).into(),
 			MathBlock(e) => MathBlock(e),
 			Rubric(e) => sub_res(*e, refs).into(),
-			SubstitutionDefinition(e) => SubstitutionDefinition(e),
+			SubstitutionDefinition(_) => return vec![],
 			Comment(e) => Comment(e),
 			Pending(e) => Pending(e),
 			Target(e) => Target(e),
@@ -284,7 +279,7 @@ impl ResolvableRefs for c::BodyElement {
 			SystemMessage(e) => sub_res(*e, refs).into(),
 			Figure(e) => sub_res(*e, refs).into(),
 			Table(e) => sub_res(*e, refs).into()
-		}
+		}]
 	}
 }
 
@@ -305,9 +300,9 @@ impl ResolvableRefs for c::BibliographicElement {
 			Field(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::BibliographicElement::*;
-		match self {
+		vec![match self {
 			Author(e) => sub_res(*e, refs).into(),
 			Authors(e) => sub_res(*e, refs).into(),
 			Organization(e) => sub_res(*e, refs).into(),
@@ -319,7 +314,7 @@ impl ResolvableRefs for c::BibliographicElement {
 			Date(e) => sub_res(*e, refs).into(),
 			Copyright(e) => sub_res(*e, refs).into(),
 			Field(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
@@ -351,10 +346,10 @@ impl ResolvableRefs for c::TextOrInlineElement {
 			ImageInline(_) => {}
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::TextOrInlineElement::*;
-		match self {
-			c::TextOrInlineElement::String(e) => c::TextOrInlineElement::String(e),
+		vec![match self {
+			String(e) => String(e),
 			Emphasis(e) => sub_res(*e, refs).into(),
 			Strong(e) => sub_res(*e, refs).into(),
 			Literal(e) => sub_res(*e, refs).into(),
@@ -375,7 +370,7 @@ impl ResolvableRefs for c::TextOrInlineElement {
 					if *ltrim || *rtrim {
 						dbg!(content, ltrim, rtrim);
 					}
-					ImageInline(Box::new(content.clone()))
+					return content.clone()
 				},
 				None => {
 					// Undefined substitution name (level 3 system message).
@@ -404,7 +399,7 @@ impl ResolvableRefs for c::TextOrInlineElement {
 			TargetInline(e) => TargetInline(e),
 			RawInline(e) => RawInline(e),
 			ImageInline(e) => ImageInline(e)
-		}
+		}]
 	}
 }
 
@@ -418,14 +413,14 @@ impl ResolvableRefs for c::AuthorInfo {
 			Contact(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::AuthorInfo::*;
-		match self {
+		vec![match self {
 			Author(e) => sub_res(*e, refs).into(),
 			Organization(e) => sub_res(*e, refs).into(),
 			Address(e) => sub_res(*e, refs).into(),
 			Contact(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
@@ -437,12 +432,12 @@ impl ResolvableRefs for c::DecorationElement {
 			Footer(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::DecorationElement::*;
-		match self {
+		vec![match self {
 			Header(e) => sub_res(*e, refs).into(),
 			Footer(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
@@ -454,11 +449,11 @@ impl ResolvableRefs for c::SubTopic {
 			BodyElement(e) => e.populate_targets(refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubTopic::*;
 		match self {
-			Title(e) => sub_res(*e, refs).into(),
-			BodyElement(e) => e.resolve_refs(refs).into(),
+			Title(e) => vec![sub_res(*e, refs).into()],
+			BodyElement(e) => e.resolve_refs(refs).drain(..).map(Into::into).collect(),
 		}
 	}
 }
@@ -473,14 +468,14 @@ impl ResolvableRefs for c::SubSidebar {
 			BodyElement(e) => e.populate_targets(refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubSidebar::*;
-		match self {
+		vec![match self {
 			Topic(e) => sub_res(*e, refs).into(),
 			Title(e) => sub_res(*e, refs).into(),
 			Subtitle(e) => sub_res(*e, refs).into(),
-			BodyElement(e) => e.resolve_refs(refs).into(),
-		}
+			BodyElement(e) => return e.resolve_refs(refs).drain(..).map(Into::into).collect(),
+		}]
 	}
 }
 
@@ -493,13 +488,13 @@ impl ResolvableRefs for c::SubDLItem {
 			Definition(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubDLItem::*;
-		match self {
+		vec![match self {
 			Term(e) => sub_res(*e, refs).into(),
 			Classifier(e) => sub_res(*e, refs).into(),
 			Definition(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
@@ -511,12 +506,12 @@ impl ResolvableRefs for c::SubField {
 			FieldBody(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubField::*;
-		match self {
+		vec![match self {
 			FieldName(e) => sub_res(*e, refs).into(),
 			FieldBody(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
@@ -528,18 +523,18 @@ impl ResolvableRefs for c::SubOptionListItem {
 			Description(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubOptionListItem::*;
-		match self {
+		vec![match self {
 			OptionGroup(e) => sub_sub_res(*e, refs).into(),
 			Description(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
 impl ResolvableRefs for c::SubOption {
 	fn populate_targets(&self, _: &mut TargetsCollected) {}
-	fn resolve_refs(self, _: &TargetsCollected) -> Self { self }
+	fn resolve_refs(self, _: &TargetsCollected) -> Vec<Self> { vec![self] }
 }
 
 impl ResolvableRefs for c::SubLineBlock {
@@ -550,12 +545,12 @@ impl ResolvableRefs for c::SubLineBlock {
 			Line(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubLineBlock::*;
-		match self {
+		vec![match self {
 			LineBlock(e) => sub_res(*e, refs).into(),
 			Line(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
@@ -567,11 +562,11 @@ impl ResolvableRefs for c::SubBlockQuote {
 			BodyElement(e) => e.populate_targets(refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubBlockQuote::*;
 		match self {
-			Attribution(e) => sub_res(*e, refs).into(),
-			BodyElement(e) => e.resolve_refs(refs).into(),
+			Attribution(e) => vec![sub_res(*e, refs).into()],
+			BodyElement(e) => e.resolve_refs(refs).drain(..).map(Into::into).collect(),
 		}
 	}
 }
@@ -584,11 +579,11 @@ impl ResolvableRefs for c::SubFootnote {
 			BodyElement(e) => e.populate_targets(refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubFootnote::*;
 		match self {
-			Label(e) => sub_res(*e, refs).into(),
-			BodyElement(e) => e.resolve_refs(refs).into(),
+			Label(e) => vec![sub_res(*e, refs).into()],
+			BodyElement(e) => e.resolve_refs(refs).drain(..).map(Into::into).collect(),
 		}
 	}
 }
@@ -602,13 +597,13 @@ impl ResolvableRefs for c::SubFigure {
 			BodyElement(e) => e.populate_targets(refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubFigure::*;
-		match self {
+		vec![match self {
 			Caption(e) => sub_res(*e, refs).into(),
 			Legend(e) => sub_res(*e, refs).into(),
-			BodyElement(e) => e.resolve_refs(refs).into(),
-		}
+			BodyElement(e) => return e.resolve_refs(refs).drain(..).map(Into::into).collect(),
+		}]
 	}
 }
 
@@ -620,12 +615,12 @@ impl ResolvableRefs for c::SubTable {
 			TableGroup(e) => sub_pop(&**e, refs),
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubTable::*;
-		match self {
+		vec![match self {
 			Title(e) => sub_res(*e, refs).into(),
 			TableGroup(e) => sub_res(*e, refs).into(),
-		}
+		}]
 	}
 }
 
@@ -648,9 +643,9 @@ impl ResolvableRefs for c::SubTableGroup {
 			},
 		}
 	}
-	fn resolve_refs(self, refs: &TargetsCollected) -> Self {
+	fn resolve_refs(self, refs: &TargetsCollected) -> Vec<Self> {
 		use c::SubTableGroup::*;
-		match self {
+		vec![match self {
 			TableColspec(e) => TableColspec(e),
 			TableHead(mut e) => {
 				let new: Vec<_> = e.children_mut().drain(..).map(|c| sub_sub_res(c, refs)).collect();
@@ -662,6 +657,6 @@ impl ResolvableRefs for c::SubTableGroup {
 				e.children_mut().extend(new);
 				TableBody(e)
 			},
-		}
+		}]
 	}
 }
diff --git a/src/parser/tests.rs b/src/parser/tests.rs
index ee33c8a..075b750 100644
--- a/src/parser/tests.rs
+++ b/src/parser/tests.rs
@@ -134,6 +134,32 @@ A |subst| in-line
 	};
 }
 
+
+#[allow(clippy::cognitive_complexity)]
+#[test]
+fn substitution_image() {
+	parses_to! {
+		parser: RstParser,
+		input: "\
+.. |subst| image:: thing.png
+   :target: foo.html
+",
+		rule: Rule::document,
+		tokens: [
+			substitution_def(0, 50, [
+				substitution_name(4, 9),
+				image(11, 50, [
+					line(18, 29, [ str(18, 28) ]),
+					image_option(32, 50, [
+						image_opt_name(33, 39),
+						line(40, 50, [ str(40, 49) ]),
+					]),
+				]),
+			]),
+		]
+	};
+}
+
 // TODO: test images
 
 #[allow(clippy::cognitive_complexity)]
diff --git a/src/renderer/html.rs b/src/renderer/html.rs
index 421d511..56e3175 100644
--- a/src/renderer/html.rs
+++ b/src/renderer/html.rs
@@ -9,7 +9,7 @@ use crate::document_tree::{
 	ExtraAttributes,
 	elements as e,
 	element_categories as c,
-	// extra_attributes as a,
+	extra_attributes as a,
 };
 
 
@@ -98,11 +98,33 @@ impl HTMLRender for e::Topic {
 
 impl_html_render_cat!(BodyElement { Paragraph, LiteralBlock, DoctestBlock, MathBlock, Rubric, SubstitutionDefinition, Comment, Pending, Target, Raw, Image, Compound, Container, BulletList, EnumeratedList, DefinitionList, FieldList, OptionList, LineBlock, BlockQuote, Admonition, Attention, Hint, Note, Caution, Danger, Error, Important, Tip, Warning, Footnote, Citation, SystemMessage, Figure, Table });
 impl_html_render_simple!(Paragraph => p, LiteralBlock => pre, MathBlock => math, Rubric => a, Compound => p, Container => div, BulletList => ul, EnumeratedList => ol, DefinitionList => dl, FieldList => dl, OptionList => pre, LineBlock => div, BlockQuote => blockquote, Admonition => aside, Attention => aside, Hint => aside, Note => aside, Caution => aside, Danger => aside, Error => aside, Important => aside, Tip => aside, Warning => aside, Figure => figure);
-impl_html_render_simple_nochildren!(Image => img, Table => table);  //TODO: after implementing the table, move it to elems with children
+impl_html_render_simple_nochildren!(Table => table);  //TODO: after implementing the table, move it to elems with children
+
+impl<I> HTMLRender for I where I: e::Element + a::ExtraAttributes<a::Image> {
+	fn render_html<W>(&self, stream: &mut W) -> Result<(), Error> where W: Write {
+		let extra = self.extra();
+		if let Some(ref target) = extra.target {
+			write!(stream, "<a href=\"{}\">", target)?;
+		}
+		write!(stream, "<img src=\"{}\"", extra.uri)?;
+		if let Some(ref alt) = extra.alt {
+			write!(stream, " alt=\"{}\"", alt)?;
+		}
+		// TODO: align: Option<AlignHV>
+		// TODO: height: Option<Measure>
+		// TODO: width: Option<Measure>
+		// TODO: scale: Option<u8>
+		write!(stream, ">")?;
+		if extra.target.is_some() {
+			write!(stream, "</a>")?;
+		}
+		Ok(())
+	}
+}
 
 impl HTMLRender for e::DoctestBlock {
 	fn render_html<W>(&self, _stream: &mut W) -> Result<(), Error> where W: Write {
-		// 
+		// TODO
 		unimplemented!();
 	}
 }
@@ -173,7 +195,6 @@ impl HTMLRender for e::SystemMessage {
 
 impl_html_render_cat!(TextOrInlineElement { String, Emphasis, Strong, Literal, Reference, FootnoteReference, CitationReference, SubstitutionReference, TitleReference, Abbreviation, Acronym, Superscript, Subscript, Inline, Problematic, Generated, Math, TargetInline, RawInline, ImageInline });
 impl_html_render_simple!(Emphasis => em, Strong => strong, Literal => code, FootnoteReference => a, CitationReference => a, TitleReference => a, Abbreviation => abbr, Acronym => acronym, Superscript => sup, Subscript => sub, Inline => span, Math => math, TargetInline => a);
-impl_html_render_simple_nochildren!(ImageInline => img);
 
 impl HTMLRender for String {
 	fn render_html<W>(&self, stream: &mut W) -> Result<(), Error> where W: Write {
@@ -293,8 +314,7 @@ impl HTMLRender for e::Legend {
 //TODO: render admonitions: Admonition, Attention, Hint, Note, Caution, Danger, Error, Important, Tip, Warning
 //TODO: properly render tables
 
-//TODO: add reference target: Reference, FootnoteReference, CitationReference, TitleReference
+//TODO: add reference target: FootnoteReference, CitationReference, TitleReference
 //TODO: add title: Abbr, Acronym
 //TODO: convert math, set display attr
 //TODO: add id: Rubric, Target, TargetInline
-//TODO: add src: Image, ImageInline
diff --git a/src/rst.pest b/src/rst.pest
index 96652a2..a88e3b3 100644
--- a/src/rst.pest
+++ b/src/rst.pest
@@ -72,7 +72,7 @@ paragraph =  { inlines }
 
 
 // Directives with options can have these or specific ones:
-common_option = { "class" | "name" }
+common_opt_name = { "class" | "name" }
 
 // Replace. A directive only usable in substitutions.
 
@@ -82,8 +82,9 @@ replace = { ^"replace::" ~ line }  // TODO multiline
 
 image_directive = _{ ".." ~ PUSH(" "+) ~ image ~ DROP }
 image           =  { ^"image::" ~ line ~ image_opt_block? }
-image_opt_block = _{ PEEK[..-1] ~ PUSH("  " ~ POP) ~ ":" ~ image_option ~ ":" ~ line } //TODO: merge with other directives?
-image_option    =  { common_option | "alt" | "height" | "width" | "scale" | "align" | "target" }
+image_opt_block = _{ PEEK[..-1] ~ PUSH("  " ~ POP) ~ image_option } //TODO: merge with other directives?
+image_option    =  { ":" ~ image_opt_name ~ ":" ~ line }
+image_opt_name  =  { common_opt_name | "alt" | "height" | "width" | "scale" | "align" | "target" }
 
 // Admonition. A directive. The generic one has a title