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use crate::{SourceMapBuilder, Span};
pub trait ToString {
fn push(&mut self, chr: char);
fn push_new_line(&mut self);
fn push_str(&mut self, string: &str);
fn push_str_contains_new_line(&mut self, string: &str);
fn add_mapping(&mut self, source_span: &Span);
}
impl ToString for String {
fn push(&mut self, chr: char) {
self.push(chr);
}
fn push_new_line(&mut self) {
self.push('\n');
}
fn push_str(&mut self, string: &str) {
self.push_str(string)
}
fn push_str_contains_new_line(&mut self, string: &str) {
self.push_str(string)
}
fn add_mapping(&mut self, _source_span: &Span) {}
}
pub struct StringWithSourceMap(String, SourceMapBuilder);
impl StringWithSourceMap {
pub fn new() -> Self {
Self(String::new(), SourceMapBuilder::new())
}
pub fn build(self) -> (String, String) {
(self.0, self.1.build())
}
}
impl ToString for StringWithSourceMap {
fn push(&mut self, chr: char) {
self.1.add_to_column(chr.len_utf16());
self.0.push(chr);
}
fn push_new_line(&mut self) {
self.1.add_new_line();
self.0.push('\n');
}
fn push_str(&mut self, slice: &str) {
self.1.add_to_column(slice.chars().count());
self.0.push_str(slice);
}
fn push_str_contains_new_line(&mut self, slice: &str) {
for chr in slice.chars() {
if chr == '\n' {
self.1.add_new_line()
}
}
self.0.push_str(slice);
}
fn add_mapping(&mut self, source_span: &Span) {
self.1.add_mapping(source_span);
}
}
pub struct Counter(usize);
impl Counter {
pub fn new() -> Self {
Self(0)
}
pub fn get_count(self) -> usize {
self.0
}
}
impl ToString for Counter {
fn push(&mut self, chr: char) {
self.0 += chr.len_utf8();
}
fn push_new_line(&mut self) {
self.push('\n');
}
fn push_str(&mut self, string: &str) {
self.0 += string.len();
}
fn push_str_contains_new_line(&mut self, string: &str) {
self.0 += string.len();
}
fn add_mapping(&mut self, _source_span: &Span) {}
}
#[cfg(test)]
mod to_string_tests {
use super::{Counter, ToString};
fn serializer<T: ToString>(t: &mut T) {
t.push_str("Hello");
t.push(' ');
t.push_str("World");
}
#[test]
fn string_concatenation() {
let mut s = String::new();
serializer(&mut s);
assert_eq!(&s, "Hello World");
}
#[test]
fn counting() {
let mut s = Counter::new();
serializer(&mut s);
assert_eq!(s.get_count(), 11);
}
}