Add subtext parsing

- lots of fixes
- kinda works

.gitignore

@@ -1,3 +1,5 @@
 /target
 **/*.rs.bk
 .idea
+.ast
+test

src/main.rs

@@ -1,3 +1,8 @@
+use markdown_rs::parser::Parser;
+use std::fs::{read_to_string, write};
+
 fn main() {
-    println!("Hello, world!");
+    let mut parser = Parser::new(read_to_string("test/document.md").unwrap());
+    let document = parser.parse();
+    write("test/document.ast", format!("{:#?}", document)).unwrap();
 }

src/parser.rs

@@ -3,6 +3,15 @@ use std::error::Error;
 use std::fmt;
 use std::fmt::{Display, Formatter};
 
+macro_rules! parse_option {
+    ($option:expr, $index:expr) => {
+        if let Some(_) = $option {
+        } else {
+            return Err(ParseError::new($index));
+        }
+    };
+}
+
 #[derive(Debug)]
 pub struct ParseError {
     index: usize,
@@ -24,9 +33,25 @@ pub struct Parser {
     text: Vec<char>,
     current_char: char,
     section_nesting: u8,
+    section_return: Option<u8>,
 }
 
 impl Parser {
+    pub fn new(text: String) -> Self {
+        let text: Vec<char> = text.chars().collect();
+        let current_char = text.get(0).unwrap().clone();
+
+        Self {
+            index: 0,
+            text,
+            current_char,
+            section_nesting: 0,
+            section_return: None,
+        }
+    }
+
+    /// Increments the current index and returns the
+    /// char at the indexes position
     pub fn next_char(&mut self) -> Option<char> {
         self.index += 1;
 
@@ -35,8 +60,9 @@ impl Parser {
         Some(self.current_char)
     }
 
+    /// Returns to an index position
     pub fn revert_to(&mut self, index: usize) -> Result<(), ParseError> {
-        self.index = index;
+        self.index = index - 1;
         if let Some(_) = self.next_char() {
             Ok(())
         } else {
@@ -44,6 +70,20 @@ impl Parser {
         }
     }
 
+    /// Skips characters until it encounters a character
+    /// that isn't an inline whitespace character
+    pub fn seek_inline_whitespace(&mut self) {
+        if self.current_char.is_whitespace() && self.current_char != '\n' {
+            while let Some(next_char) = self.next_char() {
+                if !next_char.is_whitespace() || self.current_char == '\n' {
+                    break;
+                }
+            }
+        }
+    }
+
+    /// Skips characters until it encounters a character
+    /// that isn't a whitespace character
     pub fn seek_whitespace(&mut self) {
         if self.current_char.is_whitespace() {
             while let Some(next_char) = self.next_char() {
@@ -54,19 +94,30 @@ impl Parser {
         }
     }
 
-    pub fn parse(&mut self) {
+    pub fn parse(&mut self) -> Document {
         let mut document = Document::new();
         while self.index < self.text.len() {
             if let Ok(token) = self.parse_block() {
                 document.add_element(token);
             }
         }
+
+        document
     }
 
+    /// Parses a block Token
     pub fn parse_block(&mut self) -> Result<Block, ParseError> {
-        if let Some(_) = self.next_char() {
+        if let Some(section) = self.section_return {
+            if section <= self.section_nesting {
+                return Err(ParseError::new(self.index));
+            } else {
+                self.section_return = None;
+            }
+        }
         let token = if let Ok(section) = self.parse_section() {
             Block::Section(section)
+        } else if let Some(_) = self.section_return {
+            return Err(ParseError::new(self.index));
         } else if let Ok(list) = self.parse_list() {
             Block::List(list)
         } else if let Ok(table) = self.parse_table() {
@@ -78,14 +129,12 @@ impl Parser {
         };
 
         Ok(token)
-        } else {
-            Err(ParseError::new(self.index))
-        }
     }
 
     /// Parses a section that consists of a header and one or more blocks
     pub fn parse_section(&mut self) -> Result<Section, ParseError> {
         let start_index = self.index;
+        self.seek_whitespace();
         if self.current_char == '#' {
             let mut size = 1;
             while let Some(next_char) = self.next_char() {
@@ -97,10 +146,13 @@ impl Parser {
             }
             if size <= self.section_nesting || !self.current_char.is_whitespace() {
                 let index = self.index;
+                if size <= self.section_nesting {
+                    self.section_return = Some(size);
+                }
                 self.revert_to(start_index)?;
                 return Err(ParseError::new(index));
             }
-            self.seek_whitespace();
+            self.seek_inline_whitespace();
             let mut header = self.parse_header()?;
             header.size = size;
             self.section_nesting = size;
@@ -110,16 +162,23 @@ impl Parser {
                 section.add_element(block);
             }
 
+            self.section_nesting -= 1;
             Ok(section)
         } else {
-            Err(ParseError::new(self.index))
+            let error_index = self.index;
+            self.revert_to(start_index)?;
+            Err(ParseError::new(error_index))
         }
     }
 
+    /// Parses a paragraph
     pub fn parse_paragraph(&mut self) -> Result<Paragraph, ParseError> {
         let mut paragraph = Paragraph::new();
         while let Ok(token) = self.parse_inline() {
             paragraph.add_element(token);
+            if ['-', '#', '`', '|'].contains(&self.current_char) {
+                break;
+            }
         }
 
         if paragraph.elements.len() > 0 {
@@ -129,12 +188,25 @@ impl Parser {
         }
     }
 
+    /// parses a list which consists of one or more list items
     pub fn parse_list(&mut self) -> Result<List, ParseError> {
-        unimplemented!()
+        let mut list = List::new();
+        let start_index = self.index;
+        self.seek_whitespace();
+        while let Ok(token) = self.parse_list_item() {
+            list.add_item(token);
+        }
+
+        if list.items.len() > 0 {
+            Ok(list)
+        } else {
+            self.revert_to(start_index)?;
+            Err(ParseError::new(self.index))
+        }
     }
 
     pub fn parse_table(&mut self) -> Result<Table, ParseError> {
-        unimplemented!()
+        Err(ParseError::new(self.index))
     }
 
     pub fn parse_header(&mut self) -> Result<Header, ParseError> {
@@ -144,15 +216,118 @@ impl Parser {
         })
     }
 
+    /// parses a single list item defined with -
     pub fn parse_list_item(&mut self) -> Result<ListItem, ParseError> {
-        unimplemented!()
+        let start_index = self.index;
+        self.seek_inline_whitespace();
+
+        if self.current_char != '-' {
+            let err = ParseError::new(self.index);
+            self.revert_to(start_index)?;
+            return Err(err);
+        }
+        self.seek_inline_whitespace();
+        let item = ListItem {
+            text: self.parse_inline()?,
+        };
+
+        Ok(item)
     }
 
     pub fn parse_inline(&mut self) -> Result<Inline, ParseError> {
-        unimplemented!()
+        if self.index > self.text.len() {
+            Err(ParseError::new(self.index))
+        } else {
+            Ok(Inline::Text(self.parse_text()?))
+        }
     }
 
+    /// Parses a line of text
     pub fn parse_text(&mut self) -> Result<Text, ParseError> {
-        unimplemented!()
+        let mut text = Text::new();
+        while let Ok(subtext) = self.parse_subtext() {
+            text.add_subtext(subtext);
+            let current_index = self.index;
+            if self.next_char() == None {
+                break;
+            }
+            self.revert_to(current_index)?;
+        }
+
+        if self.current_char == '\n' {
+            parse_option!(self.next_char(), self.index);
+        }
+
+        Ok(text)
+    }
+
+    pub fn parse_subtext(&mut self) -> Result<SubText, ParseError> {
+        match self.current_char {
+            '*' => {
+                parse_option!(self.next_char(), self.index);
+
+                if self.current_char == '*' {
+                    parse_option!(self.next_char(), self.index);
+                    let subtext = self.parse_subtext()?;
+                    if self.current_char == '*' {
+                        parse_option!(self.next_char(), self.index);
+                        if self.current_char == '*' {
+                            parse_option!(self.next_char(), self.index);
+                        }
+                    }
+                    Ok(SubText::Bold(BoldText {
+                        value: Box::new(subtext),
+                    }))
+                } else {
+                    let subtext = self.parse_subtext()?;
+                    parse_option!(self.next_char(), self.index);
+                    Ok(SubText::Italic(ItalicText {
+                        value: Box::new(subtext),
+                    }))
+                }
+            }
+            '_' => {
+                parse_option!(self.next_char(), self.index);
+                let subtext = self.parse_subtext()?;
+                parse_option!(self.next_char(), self.index);
+                Ok(SubText::Underlined(UnderlinedText {
+                    value: Box::new(subtext),
+                }))
+            }
+            '~' => {
+                parse_option!(self.next_char(), self.index);
+                let subtext = self.parse_subtext()?;
+                if self.current_char == '~' {
+                    parse_option!(self.next_char(), self.index);
+                }
+                Ok(SubText::Striked(StrikedText {
+                    value: Box::new(subtext),
+                }))
+            }
+            '\n' => Err(ParseError::new(self.index)),
+            _ => Ok(SubText::Plain(self.parse_plain_text()?)),
+        }
+    }
+
+    pub fn parse_plain_text(&mut self) -> Result<PlainText, ParseError> {
+        let mut current_char = self.current_char;
+        let mut characters = String::new();
+        loop {
+            match current_char {
+                '\n' | '*' | '_' | '~' => break,
+                _ => characters.push(current_char),
+            }
+            if let Some(character) = self.next_char() {
+                current_char = character;
+            } else {
+                break;
+            }
+        }
+
+        if characters.len() > 0 {
+            Ok(PlainText { value: characters })
+        } else {
+            Err(ParseError::new(self.index))
+        }
     }
 }

src/tokens.rs

@@ -1,5 +1,4 @@
-use std::ops::Sub;
+#[derive(Clone, Debug)]
-
 pub enum Block {
     Section(Section),
     Paragraph(Paragraph),
@@ -7,67 +6,82 @@ pub enum Block {
     Table(Table),
 }
 
+#[derive(Clone, Debug)]
 pub enum Inline {
     Text(Text),
 }
 
+#[derive(Clone, Debug)]
 pub struct Document {
     elements: Vec<Block>,
 }
 
+#[derive(Clone, Debug)]
 pub struct Section {
     header: Header,
     elements: Vec<Block>,
 }
 
+#[derive(Clone, Debug)]
 pub struct Header {
     pub size: u8,
     pub line: Inline,
 }
 
+#[derive(Clone, Debug)]
 pub struct BlockQuote {
     paragraph: Paragraph,
 }
 
+#[derive(Clone, Debug)]
 pub struct Paragraph {
     pub elements: Vec<Inline>,
 }
 
+#[derive(Clone, Debug)]
 pub struct List {
     pub ordered: bool,
     pub items: Vec<ListItem>,
 }
 
+#[derive(Clone, Debug)]
 pub struct ListItem {
-    text: Inline,
+    pub(crate) text: Inline,
 }
 
+#[derive(Clone, Debug)]
 pub struct Table {
     header: Row,
     rows: Vec<Row>,
 }
 
+#[derive(Clone, Debug)]
 pub struct Row {
     text: Vec<Cell>,
 }
 
+#[derive(Clone, Debug)]
 pub struct Cell {
     text: Inline,
 }
 
+#[derive(Clone, Debug)]
 pub struct CodeBlock {
     language: String,
     code: String,
 }
 
+#[derive(Clone, Debug)]
 pub struct Code {
     code: String,
 }
 
+#[derive(Clone, Debug)]
 pub struct Text {
-    subtext: Vec<SubText>,
+    pub subtext: Vec<SubText>,
 }
 
+#[derive(Clone, Debug)]
 pub enum SubText {
     Plain(PlainText),
     Code(Code),
@@ -77,24 +91,29 @@ pub enum SubText {
     Striked(StrikedText),
 }
 
+#[derive(Clone, Debug)]
 pub struct PlainText {
-    value: String,
+    pub(crate) value: String,
 }
 
+#[derive(Clone, Debug)]
 pub struct BoldText {
-    value: Box<SubText>,
+    pub(crate) value: Box<SubText>,
 }
 
+#[derive(Clone, Debug)]
 pub struct ItalicText {
-    value: Box<SubText>,
+    pub(crate) value: Box<SubText>,
 }
 
+#[derive(Clone, Debug)]
 pub struct UnderlinedText {
-    value: Box<SubText>,
+    pub(crate) value: Box<SubText>,
 }
 
+#[derive(Clone, Debug)]
 pub struct StrikedText {
-    value: Box<SubText>,
+    pub(crate) value: Box<SubText>,
 }
 
 impl Document {
@@ -147,4 +166,16 @@ impl List {
     }
 }
 
+impl Text {
+    pub fn new() -> Self {
+        Self {
+            subtext: Vec::new(),
+        }
+    }
+
+    pub fn add_subtext(&mut self, subtext: SubText) {
+        self.subtext.push(subtext)
+    }
+}
+
 // TODO: Images, URIs