1 files changed, 66 insertions, 0 deletions
diff --git a/markdown/ast_code.go b/markdown/ast_code.go
new file mode 100644
index 0000000..85a3668
--- /dev/null
+++ b/markdown/ast_code.go
@@ -0,0 +1,66 @@
+package markdown
+
+import (
+	"errors"
+	"fmt"
+	"html/template"
+)
+
+var (
+	ErrUnknownCodeType          = errors.New("unkown code type")
+	ErrInvalidCodeFormat        = errors.New("invalid code format")
+	ErrInvalidCodeBlockPosition = errors.Join(ErrInvalidParagraph, errors.New("invalid code block position"))
+)
+
+type codeType uint
+
+const (
+	codeOneLine   codeType = 1
+	codeMultiLine codeType = 2
+)
+
+type astCode struct {
+	content  string
+	before   string
+	codeType codeType
+}
+
+func (a *astCode) Eval() (template.HTML, *ParseError) {
+	switch a.codeType {
+	case codeOneLine:
+		return template.HTML(fmt.Sprintf("<code>%s</code>", template.HTMLEscapeString(a.content))), nil
+	case codeMultiLine:
+		return template.HTML(fmt.Sprintf("<pre><code>%s</code></pre>", template.HTMLEscapeString(a.content))), nil
+	default:
+		return "", &ParseError{lxs: lexers{}, internal: ErrUnknownCodeType}
+	}
+}
+
+func code(lxs *lexers) (*astCode, *ParseError) {
+	tree := new(astCode)
+	current := lxs.Current().Value
+	if len(current) == 3 {
+		tree.codeType = codeMultiLine
+	} else if len(current) == 1 {
+		tree.codeType = codeOneLine
+	} else {
+		return nil, &ParseError{lxs: *lxs, internal: ErrInvalidCodeFormat}
+	}
+	started := false
+	for lxs.Next() && lxs.Current().Value != current {
+		if lxs.Current().Type == lexerBreak {
+			if tree.codeType == codeOneLine {
+				return nil, &ParseError{lxs: *lxs, internal: ErrInvalidCodeFormat}
+			}
+			if !started {
+				started = true
+			}
+		}
+		if started || tree.codeType == codeOneLine {
+			tree.content += lxs.Current().Value
+		} else {
+			tree.before += lxs.Current().Value
+		}
+	}
+	return tree, nil
+}