refactor: split stuff from src/ast.rs into smaller modules

This only moves things around, to avoid huge source code modules. It
doesn't rename functions, add unit tests, or similar.

* src/datafiles.rs: DataFile, DataFiles
* src/metata.rs: Metadata
* src/panhelper.rs: functions for querying Pandoc Attrs
* src/policy.rs: the get_basedir_from function; place for later policy
  functions
* src/typeset.rs: functions to produce Pandoc AST nodes
* srv/visitor/*: various MutVisitor implementations for traversing
  ASTs, and their helper functions

1 files changed, 49 insertions, 0 deletions

diff --git a/src/visitor/typesetting.rs b/src/visitor/typesetting.rs
new file mode 100644
index 0000000..af6ea01
--- /dev/null
+++ b/src/visitor/typesetting.rs
@@ -0,0 +1,49 @@
+use crate::panhelper;
+use crate::typeset;
+use crate::Bindings;
+
+use pandoc_ast::{Block, MutVisitor};
+
+/// Visitor for the pandoc AST.
+///
+/// This includes rendering stuff which we find as we go
+pub struct TypesettingVisitor<'a> {
+    bindings: &'a Bindings,
+}
+
+impl<'a> TypesettingVisitor<'a> {
+    pub fn new(bindings: &'a Bindings) -> Self {
+        TypesettingVisitor { bindings }
+    }
+}
+
+// Visit interesting parts of the Pandoc abstract syntax tree. The
+// document top level is a vector of blocks and we visit that and
+// replace any fenced code block with the scenario tag with a typeset
+// paragraph. Also, replace fenced code blocks with known graph markup
+// with the rendered SVG image.
+impl<'a> MutVisitor for TypesettingVisitor<'a> {
+    fn visit_vec_block(&mut self, vec_block: &mut Vec<Block>) {
+        use panhelper::is_class;
+        for block in vec_block {
+            match block {
+                Block::CodeBlock(attr, s) => {
+                    if is_class(attr, "scenario") {
+                        *block = typeset::scenario_snippet(&self.bindings, s)
+                    } else if is_class(attr, "file") {
+                        *block = typeset::file_block(attr, s)
+                    } else if is_class(attr, "dot") {
+                        *block = typeset::dot_to_block(s)
+                    } else if is_class(attr, "plantuml") {
+                        *block = typeset::plantuml_to_block(s)
+                    } else if is_class(attr, "roadmap") {
+                        *block = typeset::roadmap_to_block(s)
+                    }
+                }
+                _ => {
+                    self.visit_block(block);
+                }
+            }
+        }
+    }
+}