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use std::str;
use nom::branch::alt;
use nom::bytes::complete::{tag, take_until};
use nom::character::complete::char;
use nom::combinator::{complete, consumed, cut, map, opt, peek, value};
use nom::error::{Error, ErrorKind};
use nom::multi::{fold_many0, many0, many1, separated_list0, separated_list1};
use nom::sequence::{delimited, pair, preceded, terminated, tuple};
use nom::{error_position, IResult};
use super::{
bool_lit, char_lit, identifier, keyword, num_lit, path, skip_till, split_ws_parts, str_lit,
tag_block_end, tag_block_start, tag_comment_end, tag_comment_start, tag_expr_end,
tag_expr_start, take_content, ws, Expr, State,
};
use crate::config::WhitespaceHandling;
#[derive(Debug, PartialEq)]
pub(crate) enum Node<'a> {
Lit(&'a str, &'a str, &'a str),
Comment(Ws),
Expr(Ws, Expr<'a>),
Call(Ws, Option<&'a str>, &'a str, Vec<Expr<'a>>),
LetDecl(Ws, Target<'a>),
Let(Ws, Target<'a>, Expr<'a>),
Cond(Vec<Cond<'a>>, Ws),
Match(Ws, Expr<'a>, Vec<When<'a>>, Ws),
Loop(Loop<'a>),
Extends(&'a str),
BlockDef(Ws, &'a str, Vec<Node<'a>>, Ws),
Include(Ws, &'a str),
Import(Ws, &'a str, &'a str),
Macro(&'a str, Macro<'a>),
Raw(Ws, &'a str, &'a str, &'a str, Ws),
Break(Ws),
Continue(Ws),
}
#[derive(Debug, PartialEq)]
pub(crate) enum Target<'a> {
Name(&'a str),
Tuple(Vec<&'a str>, Vec<Target<'a>>),
Struct(Vec<&'a str>, Vec<(&'a str, Target<'a>)>),
NumLit(&'a str),
StrLit(&'a str),
CharLit(&'a str),
BoolLit(&'a str),
Path(Vec<&'a str>),
}
#[derive(Clone, Copy, Debug, PartialEq)]
pub(crate) enum Whitespace {
Preserve,
Suppress,
Minimize,
}
impl From<WhitespaceHandling> for Whitespace {
fn from(ws: WhitespaceHandling) -> Self {
match ws {
WhitespaceHandling::Suppress => Whitespace::Suppress,
WhitespaceHandling::Preserve => Whitespace::Preserve,
WhitespaceHandling::Minimize => Whitespace::Minimize,
}
}
}
#[derive(Debug, PartialEq)]
pub(crate) struct Loop<'a> {
pub(crate) ws1: Ws,
pub(crate) var: Target<'a>,
pub(crate) iter: Expr<'a>,
pub(crate) cond: Option<Expr<'a>>,
pub(crate) body: Vec<Node<'a>>,
pub(crate) ws2: Ws,
pub(crate) else_block: Vec<Node<'a>>,
pub(crate) ws3: Ws,
}
pub(crate) type When<'a> = (Ws, Target<'a>, Vec<Node<'a>>);
#[derive(Debug, PartialEq)]
pub(crate) struct Macro<'a> {
pub(crate) ws1: Ws,
pub(crate) args: Vec<&'a str>,
pub(crate) nodes: Vec<Node<'a>>,
pub(crate) ws2: Ws,
}
/// First field is "minus/plus sign was used on the left part of the item".
///
/// Second field is "minus/plus sign was used on the right part of the item".
#[derive(Clone, Copy, Debug, PartialEq)]
pub(crate) struct Ws(pub(crate) Option<Whitespace>, pub(crate) Option<Whitespace>);
pub(crate) type Cond<'a> = (Ws, Option<CondTest<'a>>, Vec<Node<'a>>);
#[derive(Debug, PartialEq)]
pub(crate) struct CondTest<'a> {
pub(crate) target: Option<Target<'a>>,
pub(crate) expr: Expr<'a>,
}
impl Node<'_> {
pub(super) fn parse<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Vec<Node<'a>>> {
parse_template(i, s)
}
}
impl Target<'_> {
pub(super) fn parse(i: &str) -> IResult<&str, Target<'_>> {
target(i)
}
}
fn expr_handle_ws(i: &str) -> IResult<&str, Whitespace> {
alt((char('-'), char('+'), char('~')))(i).map(|(s, r)| (s, Whitespace::from(r)))
}
fn parameters(i: &str) -> IResult<&str, Vec<&str>> {
delimited(
ws(char('(')),
separated_list0(char(','), ws(identifier)),
ws(char(')')),
)(i)
}
fn block_call(i: &str) -> IResult<&str, Node<'_>> {
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("call")),
cut(tuple((
opt(tuple((ws(identifier), ws(tag("::"))))),
ws(identifier),
ws(Expr::parse_arguments),
opt(expr_handle_ws),
))),
));
let (i, (pws, _, (scope, name, args, nws))) = p(i)?;
let scope = scope.map(|(scope, _)| scope);
Ok((i, Node::Call(Ws(pws, nws), scope, name, args)))
}
fn cond_if(i: &str) -> IResult<&str, CondTest<'_>> {
let mut p = preceded(
ws(keyword("if")),
cut(tuple((
opt(delimited(
ws(alt((keyword("let"), keyword("set")))),
ws(Target::parse),
ws(char('=')),
)),
ws(Expr::parse),
))),
);
let (i, (target, expr)) = p(i)?;
Ok((i, CondTest { target, expr }))
}
fn cond_block<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Cond<'a>> {
let mut p = tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
ws(keyword("else")),
cut(tuple((
opt(cond_if),
opt(expr_handle_ws),
|i| tag_block_end(i, s),
cut(|i| parse_template(i, s)),
))),
));
let (i, (_, pws, _, (cond, nws, _, block))) = p(i)?;
Ok((i, (Ws(pws, nws), cond, block)))
}
fn block_if<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut p = tuple((
opt(expr_handle_ws),
cond_if,
cut(tuple((
opt(expr_handle_ws),
|i| tag_block_end(i, s),
cut(tuple((
|i| parse_template(i, s),
many0(|i| cond_block(i, s)),
cut(tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
ws(keyword("endif")),
opt(expr_handle_ws),
))),
))),
))),
));
let (i, (pws1, cond, (nws1, _, (block, elifs, (_, pws2, _, nws2))))) = p(i)?;
let mut res = vec![(Ws(pws1, nws1), Some(cond), block)];
res.extend(elifs);
Ok((i, Node::Cond(res, Ws(pws2, nws2))))
}
fn match_else_block<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, When<'a>> {
let mut p = tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
ws(keyword("else")),
cut(tuple((
opt(expr_handle_ws),
|i| tag_block_end(i, s),
cut(|i| parse_template(i, s)),
))),
));
let (i, (_, pws, _, (nws, _, block))) = p(i)?;
Ok((i, (Ws(pws, nws), Target::Name("_"), block)))
}
fn when_block<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, When<'a>> {
let mut p = tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
ws(keyword("when")),
cut(tuple((
ws(Target::parse),
opt(expr_handle_ws),
|i| tag_block_end(i, s),
cut(|i| parse_template(i, s)),
))),
));
let (i, (_, pws, _, (target, nws, _, block))) = p(i)?;
Ok((i, (Ws(pws, nws), target, block)))
}
fn block_match<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("match")),
cut(tuple((
ws(Expr::parse),
opt(expr_handle_ws),
|i| tag_block_end(i, s),
cut(tuple((
ws(many0(ws(value((), |i| block_comment(i, s))))),
many1(|i| when_block(i, s)),
cut(tuple((
opt(|i| match_else_block(i, s)),
cut(tuple((
ws(|i| tag_block_start(i, s)),
opt(expr_handle_ws),
ws(keyword("endmatch")),
opt(expr_handle_ws),
))),
))),
))),
))),
));
let (i, (pws1, _, (expr, nws1, _, (_, arms, (else_arm, (_, pws2, _, nws2)))))) = p(i)?;
let mut arms = arms;
if let Some(arm) = else_arm {
arms.push(arm);
}
Ok((i, Node::Match(Ws(pws1, nws1), expr, arms, Ws(pws2, nws2))))
}
fn block_let(i: &str) -> IResult<&str, Node<'_>> {
let mut p = tuple((
opt(expr_handle_ws),
ws(alt((keyword("let"), keyword("set")))),
cut(tuple((
ws(Target::parse),
opt(tuple((ws(char('=')), ws(Expr::parse)))),
opt(expr_handle_ws),
))),
));
let (i, (pws, _, (var, val, nws))) = p(i)?;
Ok((
i,
if let Some((_, val)) = val {
Node::Let(Ws(pws, nws), var, val)
} else {
Node::LetDecl(Ws(pws, nws), var)
},
))
}
fn parse_loop_content<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Vec<Node<'a>>> {
s.enter_loop();
let result = parse_template(i, s);
s.leave_loop();
result
}
fn block_for<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let if_cond = preceded(ws(keyword("if")), cut(ws(Expr::parse)));
let else_block = |i| {
let mut p = preceded(
ws(keyword("else")),
cut(tuple((
opt(expr_handle_ws),
delimited(
|i| tag_block_end(i, s),
|i| parse_template(i, s),
|i| tag_block_start(i, s),
),
opt(expr_handle_ws),
))),
);
let (i, (pws, nodes, nws)) = p(i)?;
Ok((i, (pws, nodes, nws)))
};
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("for")),
cut(tuple((
ws(Target::parse),
ws(keyword("in")),
cut(tuple((
ws(Expr::parse),
opt(if_cond),
opt(expr_handle_ws),
|i| tag_block_end(i, s),
cut(tuple((
|i| parse_loop_content(i, s),
cut(tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
opt(else_block),
ws(keyword("endfor")),
opt(expr_handle_ws),
))),
))),
))),
))),
));
let (i, (pws1, _, (var, _, (iter, cond, nws1, _, (body, (_, pws2, else_block, _, nws2)))))) =
p(i)?;
let (nws3, else_block, pws3) = else_block.unwrap_or_default();
Ok((
i,
Node::Loop(Loop {
ws1: Ws(pws1, nws1),
var,
iter,
cond,
body,
ws2: Ws(pws2, nws3),
else_block,
ws3: Ws(pws3, nws2),
}),
))
}
fn block_extends(i: &str) -> IResult<&str, Node<'_>> {
let (i, (_, name)) = tuple((ws(keyword("extends")), ws(str_lit)))(i)?;
Ok((i, Node::Extends(name)))
}
fn block_block<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut start = tuple((
opt(expr_handle_ws),
ws(keyword("block")),
cut(tuple((ws(identifier), opt(expr_handle_ws), |i| {
tag_block_end(i, s)
}))),
));
let (i, (pws1, _, (name, nws1, _))) = start(i)?;
let mut end = cut(tuple((
|i| parse_template(i, s),
cut(tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
ws(keyword("endblock")),
cut(tuple((opt(ws(keyword(name))), opt(expr_handle_ws)))),
))),
)));
let (i, (contents, (_, pws2, _, (_, nws2)))) = end(i)?;
Ok((
i,
Node::BlockDef(Ws(pws1, nws1), name, contents, Ws(pws2, nws2)),
))
}
fn block_include(i: &str) -> IResult<&str, Node<'_>> {
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("include")),
cut(pair(ws(str_lit), opt(expr_handle_ws))),
));
let (i, (pws, _, (name, nws))) = p(i)?;
Ok((i, Node::Include(Ws(pws, nws), name)))
}
fn block_import(i: &str) -> IResult<&str, Node<'_>> {
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("import")),
cut(tuple((
ws(str_lit),
ws(keyword("as")),
cut(pair(ws(identifier), opt(expr_handle_ws))),
))),
));
let (i, (pws, _, (name, _, (scope, nws)))) = p(i)?;
Ok((i, Node::Import(Ws(pws, nws), name, scope)))
}
fn block_macro<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut start = tuple((
opt(expr_handle_ws),
ws(keyword("macro")),
cut(tuple((
ws(identifier),
ws(parameters),
opt(expr_handle_ws),
|i| tag_block_end(i, s),
))),
));
let (i, (pws1, _, (name, params, nws1, _))) = start(i)?;
let mut end = cut(tuple((
|i| parse_template(i, s),
cut(tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
ws(keyword("endmacro")),
cut(tuple((opt(ws(keyword(name))), opt(expr_handle_ws)))),
))),
)));
let (i, (contents, (_, pws2, _, (_, nws2)))) = end(i)?;
assert_ne!(name, "super", "invalid macro name 'super'");
Ok((
i,
Node::Macro(
name,
Macro {
ws1: Ws(pws1, nws1),
args: params,
nodes: contents,
ws2: Ws(pws2, nws2),
},
),
))
}
fn block_raw<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let endraw = tuple((
|i| tag_block_start(i, s),
opt(expr_handle_ws),
ws(keyword("endraw")),
opt(expr_handle_ws),
peek(|i| tag_block_end(i, s)),
));
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("raw")),
cut(tuple((
opt(expr_handle_ws),
|i| tag_block_end(i, s),
consumed(skip_till(endraw)),
))),
));
let (_, (pws1, _, (nws1, _, (contents, (i, (_, pws2, _, nws2, _)))))) = p(i)?;
let (lws, val, rws) = match split_ws_parts(contents) {
Node::Lit(lws, val, rws) => (lws, val, rws),
_ => unreachable!(),
};
let ws1 = Ws(pws1, nws1);
let ws2 = Ws(pws2, nws2);
Ok((i, Node::Raw(ws1, lws, val, rws, ws2)))
}
fn break_statement<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("break")),
opt(expr_handle_ws),
));
let (j, (pws, _, nws)) = p(i)?;
if !s.is_in_loop() {
return Err(nom::Err::Failure(error_position!(i, ErrorKind::Tag)));
}
Ok((j, Node::Break(Ws(pws, nws))))
}
fn continue_statement<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut p = tuple((
opt(expr_handle_ws),
ws(keyword("continue")),
opt(expr_handle_ws),
));
let (j, (pws, _, nws)) = p(i)?;
if !s.is_in_loop() {
return Err(nom::Err::Failure(error_position!(i, ErrorKind::Tag)));
}
Ok((j, Node::Continue(Ws(pws, nws))))
}
fn block_node<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut p = tuple((
|i| tag_block_start(i, s),
alt((
block_call,
block_let,
|i| block_if(i, s),
|i| block_for(i, s),
|i| block_match(i, s),
block_extends,
block_include,
block_import,
|i| block_block(i, s),
|i| block_macro(i, s),
|i| block_raw(i, s),
|i| break_statement(i, s),
|i| continue_statement(i, s),
)),
cut(|i| tag_block_end(i, s)),
));
let (i, (_, contents, _)) = p(i)?;
Ok((i, contents))
}
fn block_comment_body<'a>(mut i: &'a str, s: &State<'_>) -> IResult<&'a str, &'a str> {
let mut level = 0;
loop {
let (end, tail) = take_until(s.syntax.comment_end)(i)?;
match take_until::<_, _, Error<_>>(s.syntax.comment_start)(i) {
Ok((start, _)) if start.as_ptr() < end.as_ptr() => {
level += 1;
i = &start[2..];
}
_ if level > 0 => {
level -= 1;
i = &end[2..];
}
_ => return Ok((end, tail)),
}
}
}
fn block_comment<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut p = tuple((
|i| tag_comment_start(i, s),
cut(tuple((
opt(expr_handle_ws),
|i| block_comment_body(i, s),
|i| tag_comment_end(i, s),
))),
));
let (i, (_, (pws, tail, _))) = p(i)?;
let nws = if tail.ends_with('-') {
Some(Whitespace::Suppress)
} else if tail.ends_with('+') {
Some(Whitespace::Preserve)
} else if tail.ends_with('~') {
Some(Whitespace::Minimize)
} else {
None
};
Ok((i, Node::Comment(Ws(pws, nws))))
}
fn expr_node<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Node<'a>> {
let mut p = tuple((
|i| tag_expr_start(i, s),
cut(tuple((
opt(expr_handle_ws),
ws(Expr::parse),
opt(expr_handle_ws),
|i| tag_expr_end(i, s),
))),
));
let (i, (_, (pws, expr, nws, _))) = p(i)?;
Ok((i, Node::Expr(Ws(pws, nws), expr)))
}
fn parse_template<'a>(i: &'a str, s: &State<'_>) -> IResult<&'a str, Vec<Node<'a>>> {
many0(alt((
complete(|i| take_content(i, s)),
complete(|i| block_comment(i, s)),
complete(|i| expr_node(i, s)),
complete(|i| block_node(i, s)),
)))(i)
}
fn variant_lit(i: &str) -> IResult<&str, Target<'_>> {
alt((
map(str_lit, Target::StrLit),
map(char_lit, Target::CharLit),
map(num_lit, Target::NumLit),
map(bool_lit, Target::BoolLit),
))(i)
}
fn target(i: &str) -> IResult<&str, Target<'_>> {
let mut opt_opening_paren = map(opt(ws(char('('))), |o| o.is_some());
let mut opt_closing_paren = map(opt(ws(char(')'))), |o| o.is_some());
let mut opt_opening_brace = map(opt(ws(char('{'))), |o| o.is_some());
let (i, lit) = opt(variant_lit)(i)?;
if let Some(lit) = lit {
return Ok((i, lit));
}
// match tuples and unused parentheses
let (i, target_is_tuple) = opt_opening_paren(i)?;
if target_is_tuple {
let (i, is_empty_tuple) = opt_closing_paren(i)?;
if is_empty_tuple {
return Ok((i, Target::Tuple(Vec::new(), Vec::new())));
}
let (i, first_target) = target(i)?;
let (i, is_unused_paren) = opt_closing_paren(i)?;
if is_unused_paren {
return Ok((i, first_target));
}
let mut targets = vec![first_target];
let (i, _) = cut(tuple((
fold_many0(
preceded(ws(char(',')), target),
|| (),
|_, target| {
targets.push(target);
},
),
opt(ws(char(','))),
ws(cut(char(')'))),
)))(i)?;
return Ok((i, Target::Tuple(Vec::new(), targets)));
}
// match structs
let (i, path) = opt(path)(i)?;
if let Some(path) = path {
let i_before_matching_with = i;
let (i, _) = opt(ws(keyword("with")))(i)?;
let (i, is_unnamed_struct) = opt_opening_paren(i)?;
if is_unnamed_struct {
let (i, targets) = alt((
map(char(')'), |_| Vec::new()),
terminated(
cut(separated_list1(ws(char(',')), target)),
pair(opt(ws(char(','))), ws(cut(char(')')))),
),
))(i)?;
return Ok((i, Target::Tuple(path, targets)));
}
let (i, is_named_struct) = opt_opening_brace(i)?;
if is_named_struct {
let (i, targets) = alt((
map(char('}'), |_| Vec::new()),
terminated(
cut(separated_list1(ws(char(',')), named_target)),
pair(opt(ws(char(','))), ws(cut(char('}')))),
),
))(i)?;
return Ok((i, Target::Struct(path, targets)));
}
return Ok((i_before_matching_with, Target::Path(path)));
}
// neither literal nor struct nor path
map(identifier, Target::Name)(i)
}
fn named_target(i: &str) -> IResult<&str, (&str, Target<'_>)> {
let (i, (src, target)) = pair(identifier, opt(preceded(ws(char(':')), target)))(i)?;
Ok((i, (src, target.unwrap_or(Target::Name(src)))))
}