Move some functions into util.

This commit is contained in:
Tom Alexander 2023-03-25 11:25:10 -04:00
parent d582c8603a
commit 3c26933e7f
Signed by: talexander
GPG Key ID: D3A179C9A53C0EDE
3 changed files with 48 additions and 46 deletions

View File

@ -27,6 +27,8 @@ use super::error::Res;
use super::object::Object;
use super::parser_with_context::parser_with_context;
use super::source::Source;
use super::util::get_consumed;
use super::util::get_one_before;
use super::Context;
#[derive(Debug)]
@ -177,48 +179,3 @@ fn start_of_line<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s st
};
Ok((input, ()))
}
/// Get one character from before the current position.
fn get_one_before<'s>(document: &'s str, current_position: &'s str) -> Option<&'s str> {
assert!(is_slice_of(document, current_position));
if document.as_ptr() as usize == current_position.as_ptr() as usize {
return None;
}
let offset = current_position.as_ptr() as usize - document.as_ptr() as usize;
let previous_character_offset = document.floor_char_boundary(offset - 1);
Some(&document[previous_character_offset..offset])
}
/// Check if the child string slice is a slice of the parent string slice.
fn is_slice_of(parent: &str, child: &str) -> bool {
let parent_start = parent.as_ptr() as usize;
let parent_end = parent_start + parent.len();
let child_start = child.as_ptr() as usize;
let child_end = child_start + child.len();
child_start >= parent_start && child_end <= parent_end
}
/// Get a slice of the string that was consumed in a parser using the original input to the parser and the remaining input after the parser.
pub fn get_consumed<'s>(input: &'s str, remaining: &'s str) -> &'s str {
assert!(is_slice_of(input, remaining));
let source = {
let offset = remaining.as_ptr() as usize - input.as_ptr() as usize;
&input[..offset]
};
source
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn get_one_before_unicode() {
let input = "🧡💛💚💙💜";
let (green_heart_index, _) = input.char_indices().skip(2).next().unwrap();
let starting_with_green_heart = &input[green_heart_index..];
let yellow_heart = get_one_before(input, starting_with_green_heart).unwrap();
assert!(is_slice_of(input, yellow_heart));
assert_eq!(yellow_heart, "💛");
}
}

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@ -8,7 +8,6 @@ use nom::combinator::recognize;
use nom::multi::many1;
use nom::sequence::tuple;
use crate::parser::document::get_consumed;
use crate::parser::object::standard_set_object;
use crate::parser::parser_context::ChainBehavior;
use crate::parser::parser_context::ContextElement;
@ -19,6 +18,7 @@ use super::error::Res;
use super::greater_element::PlainList;
use super::lesser_element::Paragraph;
use super::source::Source;
use super::util::get_consumed;
use super::Context;
#[derive(Debug)]

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@ -23,3 +23,48 @@ pub fn immediate_in_section<'r, 's, 'x>(context: Context<'r, 's>, section_name:
}
false
}
/// Get one character from before the current position.
pub fn get_one_before<'s>(document: &'s str, current_position: &'s str) -> Option<&'s str> {
assert!(is_slice_of(document, current_position));
if document.as_ptr() as usize == current_position.as_ptr() as usize {
return None;
}
let offset = current_position.as_ptr() as usize - document.as_ptr() as usize;
let previous_character_offset = document.floor_char_boundary(offset - 1);
Some(&document[previous_character_offset..offset])
}
/// Check if the child string slice is a slice of the parent string slice.
fn is_slice_of(parent: &str, child: &str) -> bool {
let parent_start = parent.as_ptr() as usize;
let parent_end = parent_start + parent.len();
let child_start = child.as_ptr() as usize;
let child_end = child_start + child.len();
child_start >= parent_start && child_end <= parent_end
}
/// Get a slice of the string that was consumed in a parser using the original input to the parser and the remaining input after the parser.
pub fn get_consumed<'s>(input: &'s str, remaining: &'s str) -> &'s str {
assert!(is_slice_of(input, remaining));
let source = {
let offset = remaining.as_ptr() as usize - input.as_ptr() as usize;
&input[..offset]
};
source
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn get_one_before_unicode() {
let input = "🧡💛💚💙💜";
let (green_heart_index, _) = input.char_indices().skip(2).next().unwrap();
let starting_with_green_heart = &input[green_heart_index..];
let yellow_heart = get_one_before(input, starting_with_green_heart).unwrap();
assert!(is_slice_of(input, yellow_heart));
assert_eq!(yellow_heart, "💛");
}
}