organic/src/parser/bold.rs

105 lines
3.8 KiB
Rust

use super::combinator::context_many_till;
use super::error::CustomError;
use super::error::MyError;
use super::error::Res;
use super::parser_context::ChainBehavior;
use super::parser_context::ContextElement;
use super::parser_context::ExitMatcherNode;
use super::text::symbol;
use super::text::text_element;
use super::token::Bold;
use super::token::TextElement;
use super::token::Token;
use super::util::in_section;
use super::Context;
use crate::parser::parser_with_context::parser_with_context;
use nom::branch::alt;
use nom::bytes::complete::tag;
use nom::combinator::map;
use nom::combinator::peek;
use nom::combinator::recognize;
use nom::sequence::tuple;
pub fn bold<'r, 's>(context: Context<'r, 's>, i: &'s str) -> Res<&'s str, Bold<'s>> {
let bold_start = parser_with_context!(context_bold_start)(&context);
let parser_context = context
.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
exit_matcher: ChainBehavior::AndParent(Some(&context_bold_end)),
}))
.with_additional_node(ContextElement::Context("bold"));
let (remaining, captured) = recognize(tuple((bold_start, |i| {
context_many_till(&parser_context, text_element, context_bold_end)(i)
})))(i)?;
let ret = Bold { source: captured };
Ok((remaining, ret))
}
fn can_start_bold<'r, 's>(context: Context<'r, 's>) -> bool {
_preceded_by_whitespace(context) && !in_section(context, "bold")
}
fn context_bold_start<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
if can_start_bold(context) {
recognize(bold_start)(input)
} else {
// TODO: Make this a specific error instead of just a generic MyError
return Err(nom::Err::Error(CustomError::MyError(MyError(
"Cannot start bold",
))));
}
}
fn context_bold_end<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
let (remaining, actual_match) = recognize(bold_end)(input)?;
peek(alt((
// Must have whitespace after the end asterisk or it must be the end of that section (as checked by the exit matcher)
tag(" "),
tag("\t"),
tag("\n"),
|i| context.check_exit_matcher(i),
)))(remaining)?;
Ok((remaining, actual_match))
}
fn bold_start(input: &str) -> Res<&str, TextElement> {
map(symbol("*"), TextElement::Symbol)(input)
}
fn bold_end(input: &str) -> Res<&str, TextElement> {
map(symbol("*"), TextElement::Symbol)(input)
}
fn _preceded_by_whitespace<'r, 's>(context: Context<'r, 's>) -> bool {
let mut context_iterator = context.iter().enumerate();
loop {
if let Some((i, ctx)) = context_iterator.next() {
match ctx.get_data() {
ContextElement::ExitMatcherNode(_) => {}
ContextElement::PreviousElementNode(previous_element_node) => {
match &previous_element_node.element {
Token::TextElement(text_element) => {
match text_element {
TextElement::Span(_) => return false,
TextElement::Space(_) => return true,
TextElement::LineBreak(_) => return true,
TextElement::Symbol(_) => return false,
TextElement::Bold(_) => return false,
TextElement::Link(_) => return false,
};
}
Token::Paragraph(_) => unreachable!(),
};
}
ContextElement::StartOfParagraph => {
return true;
}
ContextElement::Context(_) => {}
}
} else {
break;
}
}
false
}