539 lines
15 KiB
Rust
539 lines
15 KiB
Rust
//! Build-in filters
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use std::fmt;
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use std::ptr;
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use crate::{Buffer, Escape, Render, RenderError, RenderOnce};
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/// Helper struct for 'display' filter
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#[derive(Clone, Copy)]
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pub struct Display<T>(T);
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impl<T: fmt::Display> Render for Display<T> {
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fn render(&self, b: &mut Buffer) -> Result<(), RenderError> {
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use fmt::Write;
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write!(b, "{}", self.0).map_err(RenderError::from)
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}
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}
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/// render using `std::fmt::Display` trait
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///
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/// # Examples
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///
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/// ```text
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/// filename: <%\html filename.display() | disp %>
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/// ```
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#[inline]
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pub fn disp<T: fmt::Display>(expr: T) -> Display<T> {
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Display(expr)
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}
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/// Helper struct for 'dbg' filter
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#[derive(Clone, Copy)]
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pub struct Debug<T>(T);
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impl<T: fmt::Debug> Render for Debug<T> {
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fn render(&self, b: &mut Buffer) -> Result<(), RenderError> {
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use fmt::Write;
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write!(b, "{:?}", self.0).map_err(RenderError::from)
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}
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}
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/// render using `std::fmt::Debug` trait
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///
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/// # Examples
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///
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/// The following examples produce exactly same results, but former is faster
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///
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/// ```text
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/// table content: <%\html table | dbg %>
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/// ```
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///
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/// ```text
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/// table content: <%\html format!("{:?}", table) %>
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/// ```
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#[inline]
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pub fn dbg<T: fmt::Debug>(expr: T) -> Debug<T> {
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Debug(expr)
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}
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/// Helper struct for 'upper' filter
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#[derive(Clone, Copy)]
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pub struct Upper<T>(T);
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impl<T: RenderOnce> RenderOnce for Upper<T> {
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#[inline]
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fn render_once(self, b: &mut Buffer) -> Result<(), RenderError> {
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let mut tmp = Buffer::new();
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self.0.render_once(&mut tmp)?;
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// Estimate assuming ASCII and non-convertible UTF-8 are the most common.
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b.reserve(tmp.len());
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for c in tmp.as_str().chars().flat_map(|c| c.to_uppercase()) {
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b.push(c);
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}
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Ok(())
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}
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#[inline]
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fn render_once_escaped<E: Escape>(
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self,
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b: &mut Buffer,
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e: &E,
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) -> Result<(), RenderError> {
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let old_len = b.len();
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self.0.render_once(b)?;
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let mut tmp = Buffer::new();
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let s = &b.as_str()[old_len..];
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// Estimate assuming ASCII and non-convertible UTF-8 are the most common.
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tmp.reserve(s.len());
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for c in s.chars().flat_map(|c| c.to_uppercase()) {
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tmp.push(c);
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}
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unsafe { b._set_len(old_len) };
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e.escape_to_buf(b, tmp.as_str());
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Ok(())
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}
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}
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/// convert the rendered contents to uppercase
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///
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/// # Examples
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///
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/// ```text
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/// <%\html "tschüß" | upper %>
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/// ```
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///
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/// result:
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///
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/// ```text
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/// TSCHÜSS
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/// ```
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#[inline]
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pub fn upper<T: RenderOnce>(expr: T) -> Upper<T> {
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Upper(expr)
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}
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/// Helper struct for 'lower' filter
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#[derive(Clone, Copy)]
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pub struct Lower<T>(T);
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impl<T: RenderOnce> RenderOnce for Lower<T> {
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#[inline]
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fn render_once(self, b: &mut Buffer) -> Result<(), RenderError> {
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let mut tmp = Buffer::new();
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self.0.render_once(&mut tmp)?;
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// Estimate assuming ASCII and non-convertible UTF-8 are the most common.
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b.reserve(tmp.len());
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let old_len = b.len();
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for c in tmp.as_str().chars() {
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// See comments in str::to_lowercase
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if c == 'Σ' {
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// This is very inefficient, but it seems unlikely to be worth the effort
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// duplicating what already exists in the standard library for unicode support.
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let lower = tmp.as_str().to_lowercase();
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unsafe { b._set_len(old_len) };
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b.push_str(&lower);
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return Ok(());
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}
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for c in c.to_lowercase() {
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b.push(c);
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}
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}
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Ok(())
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}
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#[inline]
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fn render_once_escaped<E: Escape>(
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self,
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b: &mut Buffer,
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e: &E,
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) -> Result<(), RenderError> {
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let old_len = b.len();
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self.0.render_once(b)?;
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let mut tmp = Buffer::new();
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let s = &b.as_str()[old_len..];
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// Estimate assuming ASCII and non-convertible UTF-8 are the most common.
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tmp.reserve(s.len());
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for c in s.chars() {
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// see comments in str::to_lowercase
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if c == 'Σ' {
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let lower = s.to_lowercase();
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unsafe { b._set_len(old_len) };
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e.escape_to_buf(b, &lower);
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return Ok(());
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}
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for c in c.to_lowercase() {
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tmp.push(c);
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}
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}
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unsafe { b._set_len(old_len) };
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e.escape_to_buf(b, tmp.as_str());
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Ok(())
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}
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}
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/// convert the rendered contents to lowercase
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///
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/// # Examples
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///
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/// ```text
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/// <%\html "ὈΔΥΣΣΕΎΣ" | lower %>
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/// ```
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///
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/// result:
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///
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/// ```text
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/// ὀδυσσεύς
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/// ```
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#[inline]
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pub fn lower<T: RenderOnce>(expr: T) -> Lower<T> {
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Lower(expr)
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}
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/// Helper struct for 'trim' filter
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#[derive(Clone, Copy)]
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pub struct Trim<T>(T);
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impl<T: RenderOnce> RenderOnce for Trim<T> {
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#[inline]
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fn render_once(self, b: &mut Buffer) -> Result<(), RenderError> {
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let old_len = b.len();
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self.0.render_once(b)?;
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trim_impl(b, old_len)
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}
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#[inline]
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fn render_once_escaped<E: Escape>(
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self,
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b: &mut Buffer,
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e: &E,
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) -> Result<(), RenderError> {
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let old_len = b.len();
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self.0.render_once_escaped(b, e)?;
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trim_impl(b, old_len)
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}
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}
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fn trim_impl(b: &mut Buffer, old_len: usize) -> Result<(), RenderError> {
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let new_contents = b.as_str().get(old_len..).ok_or(RenderError::BufSize)?;
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let trimmed = new_contents.trim();
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let trimmed_len = trimmed.len();
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if new_contents.len() != trimmed_len {
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// performs inplace trimming
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if new_contents.as_ptr() != trimmed.as_ptr() {
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debug_assert!(new_contents.as_ptr() < trimmed.as_ptr());
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let offset = trimmed.as_ptr() as usize - new_contents.as_ptr() as usize;
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unsafe {
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ptr::copy(
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b.as_mut_ptr().add(old_len + offset),
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b.as_mut_ptr().add(old_len),
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trimmed_len,
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);
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}
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}
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debug_assert!(b.capacity() >= old_len + trimmed_len);
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// SAFETY: `new_contents.len() = b.len() - old_len` and
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// `trimmed_len < new_contents.len()`, so `old_len + trimmed_len < b.len()`.
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unsafe {
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b._set_len(old_len + trimmed_len);
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}
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}
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Ok(())
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}
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/// Remove leading and trailing writespaces from rendered results
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///
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/// # Examples
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///
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/// ```text
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/// <%\html " Hello world\n" | trim %>
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/// ```
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///
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/// result:
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///
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/// ```text
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/// Hello world
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/// ```
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#[inline]
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pub fn trim<T: RenderOnce>(expr: T) -> Trim<T> {
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Trim(expr)
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}
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/// Helper struct for 'truncate' filter
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#[derive(Clone, Copy)]
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pub struct Truncate<T>(T, usize);
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impl<T: RenderOnce> RenderOnce for Truncate<T> {
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#[inline]
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fn render_once(self, b: &mut Buffer) -> Result<(), RenderError> {
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let old_len = b.len();
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self.0.render_once(b)?;
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truncate_impl(b, old_len, self.1)
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}
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#[inline]
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fn render_once_escaped<E: Escape>(
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self,
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b: &mut Buffer,
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e: &E,
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) -> Result<(), RenderError> {
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let old_len = b.len();
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self.0.render_once_escaped(b, e)?;
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truncate_impl(b, old_len, self.1)
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}
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}
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#[cfg_attr(feature = "perf-inline", inline)]
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fn truncate_impl(
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b: &mut Buffer,
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old_len: usize,
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limit: usize,
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) -> Result<(), RenderError> {
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let new_contents = b.as_str().get(old_len..).ok_or(RenderError::BufSize)?;
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if new_contents.len() > limit {
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if let Some(idx) = new_contents.char_indices().nth(limit).map(|(i, _)| i) {
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unsafe { b._set_len(old_len + idx) };
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b.push_str("...");
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}
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}
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Ok(())
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}
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/// Limit length of rendered contents, appends '...' if truncated
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///
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/// # Examples
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///
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/// The following example renders the first 20 characters of `message`
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///
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/// ```test
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/// <%\html "Hello, world!" | truncate(5) %>
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/// ```
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///
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/// result:
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///
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/// ```text
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/// Hello...
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/// ```
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#[inline]
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pub fn truncate<T: RenderOnce>(expr: T, limit: usize) -> Truncate<T> {
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Truncate(expr, limit)
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}
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cfg_json! {
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/// Helper struct for 'json' filter
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#[derive(Clone, Copy)]
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pub struct Json<T>(T);
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impl<T: serde::Serialize> Render for Json<T> {
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#[inline]
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fn render(&self, b: &mut Buffer) -> Result<(), RenderError> {
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struct Writer<'a>(&'a mut Buffer);
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impl<'a> std::io::Write for Writer<'a> {
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#[inline]
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fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
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let buf = unsafe { std::str::from_utf8_unchecked(buf) };
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self.0.push_str(buf);
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Ok(buf.len())
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}
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#[inline]
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fn write_all(&mut self, buf: &[u8]) -> std::io::Result<()> {
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self.write(buf).map(|_| {})
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}
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#[inline]
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fn flush(&mut self) -> std::io::Result<()> {
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Ok(())
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}
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}
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serde_json::to_writer(Writer(b), &self.0)
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.map_err(|e| RenderError::new(&e.to_string()))
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}
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#[inline]
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fn render_escaped<E: Escape>(
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&self,
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b: &mut Buffer,
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e: &E,
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) -> Result<(), RenderError> {
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struct Writer<'a, E: Escape>(&'a mut Buffer, &'a E);
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impl<'a, E: Escape> std::io::Write for Writer<'a, E> {
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#[inline]
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fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
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let buf = unsafe { std::str::from_utf8_unchecked(buf) };
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self.1.escape_to_buf(self.0, buf);
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Ok(buf.len())
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}
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#[inline]
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fn write_all(&mut self, buf: &[u8]) -> std::io::Result<()> {
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self.write(buf).map(|_| {})
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}
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#[inline]
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fn flush(&mut self) -> std::io::Result<()> {
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Ok(())
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}
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}
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serde_json::to_writer(Writer(b, e), &self.0)
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.map_err(|e| RenderError::new(&e.to_string()))
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}
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}
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/// Serialize the given data structure as JSON into the buffer
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///
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/// # Examples
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///
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/// ```text
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/// {
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/// "name": "JSON example",
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/// "data": <%- data | json %>
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/// }
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/// ```
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#[inline]
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pub fn json<T: serde::Serialize>(expr: T) -> Json<T> {
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Json(expr)
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}
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}
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#[cfg(test)]
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mod tests {
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use crate::EscapeHtml;
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use super::*;
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fn assert_render<T: RenderOnce>(expr: T, expected: &str) {
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let mut buf = Buffer::new();
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RenderOnce::render_once(expr, &mut buf).unwrap();
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assert_eq!(buf.as_str(), expected);
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}
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fn assert_render_escaped<T: RenderOnce>(expr: T, expected: &str) {
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let mut buf = Buffer::new();
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RenderOnce::render_once_escaped(expr, &mut buf, &EscapeHtml).unwrap();
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assert_eq!(buf.as_str(), expected);
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}
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#[test]
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fn test_lower() {
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assert_render(lower(""), "");
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assert_render_escaped(lower(""), "");
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assert_render(lower("lorem ipsum"), "lorem ipsum");
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assert_render(lower("LOREM IPSUM"), "lorem ipsum");
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assert_render_escaped(lower("hElLo, WOrLd!"), "hello, world!");
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assert_render_escaped(lower("hElLo, WOrLd!"), "hello, world!");
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assert_render_escaped(lower("<h1>TITLE</h1>"), "<h1>title</h1>");
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assert_render_escaped(lower("<<&\"\">>"), "<<&"">>");
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// non-ascii
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assert_render(lower("aBcAbc"), "abcabc");
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assert_render(lower("ὈΔΥΣΣΕΎΣ"), "ὀδυσσεύς");
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}
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#[test]
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fn test_upper() {
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assert_render(upper(""), "");
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assert_render_escaped(upper(""), "");
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assert_render(upper("lorem ipsum"), "LOREM IPSUM");
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assert_render(upper("LOREM IPSUM"), "LOREM IPSUM");
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assert_render(upper("hElLo, WOrLd!"), "HELLO, WORLD!");
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assert_render(upper("hElLo, WOrLd!"), "HELLO, WORLD!");
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// non-ascii
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assert_render(upper("aBcAbc"), "ABCABC");
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assert_render(upper("tschüß"), "TSCHÜSS");
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}
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#[test]
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fn test_trim() {
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assert_render(trim(""), "");
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assert_render_escaped(trim(""), "");
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assert_render(trim("\n \t\r\x0C"), "");
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assert_render(trim("hello world!"), "hello world!");
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assert_render(trim("hello world!\n"), "hello world!");
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assert_render(trim("\thello world!"), "hello world!");
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assert_render(trim("\thello world!\r\n"), "hello world!");
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assert_render_escaped(trim(" <html> "), "<html>");
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assert_render_escaped(lower("<<&\"\">>"), "<<&"">>");
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// non-ascii whitespace
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assert_render(trim("\u{A0}空白\u{3000}\u{205F}"), "空白");
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}
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#[test]
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fn test_truncate() {
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assert_render(truncate("", 0), "");
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assert_render(truncate("", 5), "");
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assert_render(truncate("apple ", 0), "...");
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assert_render(truncate("apple ", 1), "a...");
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assert_render(truncate("apple ", 2), "ap...");
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assert_render(truncate("apple ", 3), "app...");
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assert_render(truncate("apple ", 4), "appl...");
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assert_render(truncate("apple ", 5), "apple...");
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assert_render(truncate("apple ", 6), "apple ");
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assert_render(truncate("apple ", 7), "apple ");
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assert_render(truncate(std::f64::consts::PI, 10), "3.14159265...");
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assert_render(truncate(std::f64::consts::PI, 20), "3.141592653589793");
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assert_render_escaped(truncate("foo<br>bar", 10), "foo<br&...");
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assert_render_escaped(truncate("foo<br>bar", 20), "foo<br>bar");
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// non-ascii
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assert_render(truncate("魑魅魍魎", 0), "...");
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assert_render(truncate("魑魅魍魎", 1), "魑...");
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assert_render(truncate("魑魅魍魎", 2), "魑魅...");
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assert_render(truncate("魑魅魍魎", 3), "魑魅魍...");
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assert_render(truncate("魑魅魍魎", 4), "魑魅魍魎");
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assert_render(truncate("魑魅魍魎", 5), "魑魅魍魎");
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}
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#[cfg(feature = "json")]
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#[test]
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fn test_json() {
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assert_render(json(""), "\"\"");
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assert_render(json(serde_json::json!({})), "{}");
|
||
|
||
assert_render_escaped(json(123_i32), "123");
|
||
assert_render_escaped(json("Pokémon"), ""Pokémon"");
|
||
}
|
||
|
||
#[test]
|
||
fn compine() {
|
||
assert_render(
|
||
lower(upper("Li Europan lingues es membres del sam familie.")),
|
||
"li europan lingues es membres del sam familie.",
|
||
);
|
||
assert_render(lower(lower("ハートのA")), "ハートのa");
|
||
assert_render(upper(upper("ハートのA")), "ハートのA");
|
||
|
||
assert_render(truncate(trim("\t起来!\r\n"), 1), "起...");
|
||
assert_render(truncate(trim("\t起来!\r\n"), 3), "起来!");
|
||
|
||
assert_render(truncate(lower("Was möchtest du?"), 10), "was möchte...");
|
||
assert_render(truncate(upper("Was möchtest du?"), 10), "WAS MÖCHTE...");
|
||
}
|
||
}
|