Structural markdown representation (#162)

include/Support/StructedText.h

@@ -0,0 +1,108 @@
+#pragma once
+
+#include "llvm/Support/raw_os_ostream.h"
+
+namespace clice {
+
+/// Base class of structed text
+class Block {
+public:
+    virtual void render_markdown(llvm::raw_ostream& os) const = 0;
+    virtual std::unique_ptr<Block> clone() const = 0;
+    std::string as_markdown() const;
+
+    virtual bool is_ruler() const {
+        return false;
+    }
+
+    virtual ~Block() = default;
+};
+
+/// Normal text and inline code
+class Paragraph : public Block {
+public:
+    enum class Kind : uint8_t {
+        Bold,
+        Italic,
+        PlainText,
+        InlineCode,
+        Strikethough,
+    };
+    void render_markdown(llvm::raw_ostream& os) const override;
+
+    std::unique_ptr<Block> clone() const override {
+        return std::make_unique<Paragraph>(*this);
+    }
+
+    Paragraph& append_text(std::string text, Kind kind = Kind::PlainText);
+
+    Paragraph& append_newline_char(unsigned cnt = 1);
+
+private:
+    struct Chunk {
+        Kind kind;
+        std::string content;
+        bool space_ahead = false;
+        bool space_after = false;
+    };
+
+    std::vector<Chunk> chunks;
+};
+
+class StructedText;
+
+/// Allow nested structure
+class BulletList : public Block {
+public:
+    BulletList();
+    ~BulletList();
+    void render_markdown(llvm::raw_ostream& os) const override;
+
+    std::unique_ptr<Block> clone() const override;
+
+    StructedText& add_item();
+
+private:
+    std::vector<StructedText> items;
+};
+
+class StructedText {
+public:
+    StructedText() = default;
+
+    StructedText(const StructedText& other) {
+        *this = other;
+    }
+
+    StructedText(StructedText&&) = default;
+
+    StructedText& operator= (const StructedText& other) {
+        blocks.clear();
+        for(auto& b: other.blocks) {
+            blocks.push_back(b->clone());
+        }
+        return *this;
+    }
+
+    StructedText& operator= (StructedText&&) = default;
+
+    void append(StructedText& doc);
+
+    Paragraph& add_paragraph();
+
+    void add_ruler();
+
+    void add_code_block(std::string code, std::string lang = "");
+
+    Paragraph& add_heading(unsigned level);
+
+    BulletList& add_bullet_list();
+
+    std::string as_markdown() const;
+
+private:
+    std::vector<std::unique_ptr<Block>> blocks;
+};
+
+}  // namespace clice
+