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use super::errors::{ParsingError, UnclosedCommentError};
use super::lang;
use program_structure::ast::AST;
use program_structure::report::Report;
use program_structure::file_definition::FileID;
pub fn preprocess(expr: &str, file_id: FileID) -> Result<String, Box<Report>> {
let mut pp = String::new();
let mut state = 0;
let mut loc = 0;
let mut block_start = 0;
let mut it = expr.chars();
while let Some(c0) = it.next() {
loc += 1;
match (state, c0) {
(0, '/') => {
loc += 1;
match it.next() {
Some('/') => {
state = 1;
pp.push(' ');
pp.push(' ');
}
Some('*') => {
block_start = loc;
state = 2;
pp.push(' ');
pp.push(' ');
}
Some(c1) => {
pp.push(c0);
pp.push(c1);
}
None => {
pp.push(c0);
break;
}
}
}
(0, _) => pp.push(c0),
(1, '\n') => {
pp.push(c0);
state = 0;
}
(2, '*') => {
loc += 1;
match it.next() {
Some('/') => {
pp.push(' ');
pp.push(' ');
state = 0;
}
Some(c) => {
pp.push(' ');
for _i in 0..c.len_utf8() {
pp.push(' ');
}
}
None => {
let error =
UnclosedCommentError { location: block_start..block_start, file_id };
return Err(Box::new(error.into_report()));
}
}
}
(_, c) => {
for _i in 0..c.len_utf8() {
pp.push(' ');
}
}
}
}
Ok(pp)
}
pub fn parse_file(src: &str, file_id: FileID) -> Result<AST, Box<Report>> {
use lalrpop_util::ParseError::*;
lang::ParseAstParser::new()
.parse(&preprocess(src, file_id)?)
.map(|mut ast| {
for include in &mut ast.includes {
include.meta.set_file_id(file_id);
}
ast
})
.map_err(|parse_error| match parse_error {
InvalidToken { location } => ParsingError {
file_id,
message: "Invalid token found.".to_string(),
location: location..location,
},
UnrecognizedToken { ref token, ref expected } => ParsingError {
file_id,
message: format!(
"Unrecognized token `{}` found.{}",
token.1,
format_expected(expected)
),
location: token.0..token.2,
},
ExtraToken { ref token } => ParsingError {
file_id,
message: format!("Extra token `{}` found.", token.2),
location: token.0..token.2,
},
_ => ParsingError { file_id, message: format!("{parse_error}"), location: 0..0 },
})
.map_err(|error| Box::new(error.into_report()))
}
pub fn parse_string(src: &str) -> Option<AST> {
let src = preprocess(src, 0).ok()?;
lang::ParseAstParser::new().parse(&src).ok()
}
use program_structure::ast::Definition;
pub fn parse_definition(src: &str) -> Option<Definition> {
match parse_string(src) {
Some(AST { mut definitions, .. }) if definitions.len() == 1 => definitions.pop(),
_ => None,
}
}
#[must_use]
fn format_expected(tokens: &[String]) -> String {
if tokens.is_empty() {
String::new()
} else {
let tokens = tokens
.iter()
.enumerate()
.map(|(index, token)| {
if index == 0 {
token.replace('\"', "`")
} else if index < tokens.len() - 1 {
format!(", {}", token.replace('\"', "`"))
} else {
format!(" or {}", token.replace('\"', "`"))
}
})
.collect::<Vec<_>>()
.join("");
format!(" Expected one of {tokens}.")
}
}
#[cfg(test)]
mod tests {
use super::parse_string;
#[test]
fn test_parse_string() {
let function = r#"
function f(m) {
// This is a comment.
var x = 1024;
var y = 16;
while (x < m) {
x += y;
}
if (x == m) {
x = 0;
}
/* This is another comment. */
return x;
}
"#;
let _ = parse_string(function);
let template = r#"
template T(m) {
signal input in[m];
signal output out;
var sum = 0;
for (var i = 0; i < m; i++) {
sum += in[i];
}
out <== sum;
}
"#;
let _ = parse_string(template);
}
}