feat: add meta tag

README.md

@@ -0,0 +1,63 @@
+# YAMD
+
+Indentation-based markup language that compiles to HTML via Ruby codegen.
+
+## Syntax
+
+Structure is defined by indentation (tabs). Lines at a given indent level belong to the enclosing directive.
+
+### Directives (line-start only)
+
+| Syntax | Description |
+|--------|-------------|
+| `#% <ruby code>` | Metadata / Ruby statement. e.g. `#% meta "date", "2025 01 01"` |
+| `#! <expr>` | Block wrapper. Evaluates `expr` as a Ruby method call, content is passed as a block. e.g. `#! tag('h1')` |
+| `#$ <expr>` | Raw block. Like `#!` but inner lines are passed as a raw string (no YAMD parsing). Used for code blocks. e.g. `#$ code` |
+| `#. ` | List item. Must appear inside a `#! list(...)` block |
+
+### Inline constructs
+
+| Syntax | Description |
+|--------|-------------|
+| `` #`...` `` | Inline code |
+| `#{expr}` | Ruby expression interpolation (result converted to string) |
+| `#(expr)` | Inline math (AsciiMath, rendered to MathML) |
+| `#name(args)` | Method call. e.g. `#link("url")` |
+| `#name(args)#{ content }#` | Method call with content block. e.g. `#link("url")#{ click here }#` |
+| `##` | Escaped literal `#` |
+| `}#` | Closes a `#{` content block |
+
+### Comments
+
+Lines matching `#` followed by nothing or a space (i.e. `#` or `# ...`) are comments and are skipped.
+
+### Available renderer methods
+
+These are defined by `HTMLRenderer` in `exe/yamd`:
+
+| Method | Usage |
+|--------|-------|
+| `tag(name, **attrs)` | HTML element. `#! tag('h2')` |
+| `list(numbering)` | List. numbering: `"-"` (ul), `"1"`, `"a"`, `"A"`, `"i"`, `"I"` (ol). Dot-separated for nested: `"-.1"` |
+| `link(url)` | Anchor tag. `#link("https://example.com")#{ text }#` |
+| `code(lang: Lang::DEFAULT)` | Code block (used via `#$`). Optional `lang:` for highlighting rules |
+| `meta(name, value)` | HTML `<meta>` tag. Used via `#%` |
+| `inline_code(text)` | Inline `<code>`. Used via `` #`...` `` |
+| `inline_math(text)` | AsciiMath to MathML. Used via `#(...)` |
+
+### Example
+
+```
+#% meta "date", "2025 01 01"
+
+#! tag('h1')
+	Title
+
+Paragraph text with #`inline code` and #link("https://example.com")#{ a link }#.
+
+#! list('-')
+	#. First item
+	#. Second item with sub-content
+		#$ code
+			x = 1
+```

exe/yamd

@@ -91,6 +91,23 @@ class HTMLRenderer < YAMD::Renderer
 		}
 	end
 
+	def single_tag(name, **attrs)
+		@buf << "<#{name}"
+		attrs.each { |k, v|
+			@buf << " "
+			if k.kind_of? Symbol
+				k = k.to_s
+			end
+			@buf << k
+			@buf << "=" << v.dump
+		}
+		@buf << "/>"
+	end
+
+	def meta(name, value)
+		single_tag('meta', name: name, content: value)
+	end
+
 	def tag(name, **attrs)
 		@buf << "<#{name}"
 		attrs.each { |k, v|