(subplot): Add support for example blocks

In support of #256, this adds `example` as a permitted class and
ensures that we typeset it as though it were a file.

This includes linting it as though it were a file too.

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

4 files changed, 10 insertions, 3 deletions

diff --git a/src/doc.rs b/src/doc.rs
index 9c5fae8..ed88e95 100644
--- a/src/doc.rs
+++ b/src/doc.rs
@@ -28,7 +28,9 @@ use log::{error, trace};
 
 /// The set of known (special) classes which subplot will always recognise
 /// as being valid.
-static SPECIAL_CLASSES: &[&str] = &["scenario", "file", "dot", "pikchr", "plantuml", "roadmap"];
+static SPECIAL_CLASSES: &[&str] = &[
+    "scenario", "file", "example", "dot", "pikchr", "plantuml", "roadmap",
+];
 
 /// The set of known (file-type) classes which subplot will always recognise
 /// as being valid.
diff --git a/src/typeset.rs b/src/typeset.rs
index 18e5a44..9522e69 100644
--- a/src/typeset.rs
+++ b/src/typeset.rs
@@ -41,6 +41,11 @@ pub fn file_block(attr: &Attr, text: &str) -> Block {
         // Otherwise if it doesn't say numberLines we add that in.
         cbattrs.1.push("numberLines".to_string());
     }
+    // If this was an `example`, convert that class to `file`
+    if cbattrs.1.iter().any(|s| s == "example") {
+        cbattrs.1.retain(|s| s != "example");
+        cbattrs.1.push("file".into());
+    }
     let codeblock = Block::CodeBlock(cbattrs, text.to_string());
     let noattr = ("".to_string(), vec![], vec![]);
     Block::Div(noattr, vec![intro, codeblock])
diff --git a/src/visitor/linting.rs b/src/visitor/linting.rs
index 03b49ee..6266516 100644
--- a/src/visitor/linting.rs
+++ b/src/visitor/linting.rs
@@ -13,7 +13,7 @@ impl MutVisitor for LintingVisitor {
         for block in vec_block {
             match block {
                 Block::CodeBlock(attr, _) => {
-                    if panhelper::is_class(attr, "file") {
+                    if panhelper::is_class(attr, "file") || panhelper::is_class(attr, "example") {
                         let newlines: Vec<_> =
                             panhelper::find_attr_kv(attr, "add-newline").collect();
                         match newlines.len() {
diff --git a/src/visitor/typesetting.rs b/src/visitor/typesetting.rs
index 8d73f3e..da9c362 100644
--- a/src/visitor/typesetting.rs
+++ b/src/visitor/typesetting.rs
@@ -40,7 +40,7 @@ impl<'a> MutVisitor for TypesettingVisitor<'a> {
                 Block::CodeBlock(attr, s) => {
                     if is_class(attr, "scenario") {
                         *block = typeset::scenario_snippet(self.bindings, s, &mut self.warnings)
-                    } else if is_class(attr, "file") {
+                    } else if is_class(attr, "file") || is_class(attr, "example") {
                         *block = typeset::file_block(attr, s)
                     } else if is_class(attr, "dot") {
                         *block = typeset::dot_to_block(s, &mut self.warnings)