bjoernager/rust
bjoernager/rust
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Format all the loops!

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This commit is contained in:
Marcus Klaas 2015-07-19 23:39:48 +02:00
parent 2fda8dd883
commit 2fa6220f57
6 changed files with 171 additions and 41 deletions
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176
src/expr.rs
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@ -56,21 +56,45 @@ impl Rewrite for ast::Expr {
ast::Expr_::ExprTup(ref items) => {
rewrite_tuple_lit(context, items, self.span, width, offset)
}
ast::Expr_::ExprWhile(ref subexpr, ref block, label) => {
let label_string = rewrite_label(label);
// 6 = "while "
// 2 = " {"
let expr_width = width - 6 - 2 - label_string.len();
let expr_offset = offset + 6 + label_string.len();
subexpr.rewrite(context, expr_width, expr_offset).and_then(|expr_string| {
// FIXME: this drops any comment between "loop" and the block.
block.rewrite(context, width, offset).map(|result| {
format!("{}while {} {}", rewrite_label(label), expr_string, result)
})
})
ast::Expr_::ExprWhile(ref cond, ref block, label) => {
rewrite_loop(context,
cond,
block,
label,
None,
"while ",
"let ",
" = ",
width,
offset)
}
ast::Expr_::ExprWhileLet(ref pat, ref cond, ref block, label) => {
rewrite_loop(context,
cond,
block,
label,
Some(pat),
"while ",
"let ",
" = ",
width,
offset)
}
ast::Expr_::ExprForLoop(ref pat, ref cond, ref block, label) => {
rewrite_loop(context,
cond,
block,
label,
Some(pat),
"for ",
"",
" in ",
width,
offset)
}
ast::Expr_::ExprLoop(ref block, label) => {
// Of all the loops, this is the only one that does not use
// rewrite_loop!
// FIXME: this drops any comment between "loop" and the block.
block.rewrite(context, width, offset).map(|result| {
format!("{}loop {}", rewrite_label(label), result)
@ -97,6 +121,14 @@ impl Rewrite for ast::Expr {
width,
offset)
}
// We reformat it ourselves because rustc gives us a bad span for ranges
ast::Expr_::ExprRange(ref left, ref right) => {
rewrite_range(context,
left.as_ref().map(|e| &**e),
right.as_ref().map(|e| &**e),
width,
offset)
}
_ => context.codemap.span_to_snippet(self.span).ok()
}
}
@ -136,6 +168,61 @@ fn rewrite_label(label: Option<ast::Ident>) -> String {
}
}
// FIXME: this doesn't play well with line breaks
fn rewrite_range(context: &RewriteContext,
left: Option<&ast::Expr>,
right: Option<&ast::Expr>,
width: usize,
offset: usize)
-> Option<String> {
let left_string = match left {
// 2 = ..
Some(expr) => try_opt!(expr.rewrite(context, width - 2, offset)),
None => String::new()
};
let right_string = match right {
Some(expr) => {
// 2 = ..
let max_width = (width - 2).checked_sub(left_string.len()).unwrap_or(0);
try_opt!(expr.rewrite(context, max_width, offset + 2 + left_string.len()))
}
None => String::new()
};
Some(format!("{}..{}", left_string, right_string))
}
fn rewrite_loop(context: &RewriteContext,
cond: &ast::Expr,
block: &ast::Block,
label: Option<ast::Ident>,
pat: Option<&ast::Pat>,
keyword: &str,
matcher: &str, // FIXME: think of better identifiers
connector: &str,
width: usize,
offset: usize)
-> Option<String> {
let label_string = rewrite_label(label);
// 2 = " {"
let inner_width = width - keyword.len() - 2 - label_string.len();
let inner_offset = offset + keyword.len() + label_string.len();
let pat_expr_string = try_opt!(rewrite_pat_expr(context,
pat,
cond,
matcher,
connector,
inner_width,
inner_offset));
// FIXME: this drops any comment between "loop" and the block.
block.rewrite(context, width, offset).map(|result| {
format!("{}{}{} {}", label_string, keyword, pat_expr_string, result)
})
}
fn rewrite_if_else(context: &RewriteContext,
cond: &ast::Expr,
if_block: &ast::Block,
@ -144,30 +231,17 @@ fn rewrite_if_else(context: &RewriteContext,
width: usize,
offset: usize)
-> Option<String> {
// FIXME: missing comments between control statements and blocks
// 3 = "if ", 2 = " {"
let pat_string = match pat {
Some(pat) => {
// 7 = "let ".len() + " = ".len()
// 4 = "let ".len()
let pat_string = try_opt!(pat.rewrite(context, width - 3 - 2 - 7, offset + 3 + 4));
format!("let {} = ", pat_string)
}
None => String::new()
};
let pat_expr_string = try_opt!(rewrite_pat_expr(context,
pat,
cond,
"let ",
" = ",
width - 3 - 2,
offset + 3));
// Consider only the last line of the pat string
let extra_offset = match pat_string.rfind('\n') {
// 1 for newline character
Some(idx) => pat_string.len() - idx - 1 - offset,
None => 3 + pat_string.len()
};
let cond_string = try_opt!(cond.rewrite(context,
width - extra_offset - 2,
offset + extra_offset));
let if_block_string = try_opt!(if_block.rewrite(context, width, offset));
let mut result = format!("if {}{} {}", pat_string, cond_string, if_block_string);
let mut result = format!("if {} {}", pat_expr_string, if_block_string);
if let Some(else_block) = else_block {
let else_block_string = try_opt!(else_block.rewrite(context, width, offset));
@ -179,6 +253,40 @@ fn rewrite_if_else(context: &RewriteContext,
Some(result)
}
fn rewrite_pat_expr(context: &RewriteContext,
pat: Option<&ast::Pat>,
expr: &ast::Expr,
matcher: &str,
connector: &str,
width: usize,
offset: usize)
-> Option<String> {
let mut result = match pat {
Some(pat) => {
let pat_string = try_opt!(pat.rewrite(context,
width - connector.len() - matcher.len(),
offset + matcher.len()));
format!("{}{}{}", matcher, pat_string, connector)
}
None => String::new()
};
// Consider only the last line of the pat string
let extra_offset = match result.rfind('\n') {
// 1 for newline character
Some(idx) => result.len() - idx - 1 - offset,
None => result.len()
};
let expr_string = try_opt!(expr.rewrite(context,
width - extra_offset,
offset + extra_offset));
result.push_str(&expr_string);
Some(result)
}
fn rewrite_string_lit(context: &RewriteContext,
s: &str,
span: Span,