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Small parser refactors (#7568)

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This commit is contained in:
Jakub Žádník
2022-12-22 13:41:44 +02:00
committed by GitHub
parent 046e46b962
commit d8a2e0e9a3
4 changed files with 376 additions and 370 deletions
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365
crates/nu-parser/src/lite_parser.rs Normal file
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/// Lite parsing converts a flat stream of tokens from the lexer to a syntax element structure that
/// can be parsed.
use crate::{ParseError, Token, TokenContents};
use nu_protocol::{ast::Redirection, Span};
#[derive(Debug)]
pub struct LiteCommand {
pub comments: Vec<Span>,
pub parts: Vec<Span>,
}
impl Default for LiteCommand {
fn default() -> Self {
Self::new()
}
}
impl LiteCommand {
pub fn new() -> Self {
Self {
comments: vec![],
parts: vec![],
}
}
pub fn push(&mut self, span: Span) {
self.parts.push(span);
}
pub fn is_empty(&self) -> bool {
self.parts.is_empty()
}
}
// Note: the Span is the span of the connector not the whole element
#[derive(Debug)]
pub enum LiteElement {
Command(Option<Span>, LiteCommand),
Redirection(Span, Redirection, LiteCommand),
}
#[derive(Debug)]
pub struct LitePipeline {
pub commands: Vec<LiteElement>,
}
impl Default for LitePipeline {
fn default() -> Self {
Self::new()
}
}
impl LitePipeline {
pub fn new() -> Self {
Self { commands: vec![] }
}
pub fn push(&mut self, element: LiteElement) {
self.commands.push(element);
}
pub fn is_empty(&self) -> bool {
self.commands.is_empty()
}
}
#[derive(Debug)]
pub struct LiteBlock {
pub block: Vec<LitePipeline>,
}
impl Default for LiteBlock {
fn default() -> Self {
Self::new()
}
}
impl LiteBlock {
pub fn new() -> Self {
Self { block: vec![] }
}
pub fn push(&mut self, pipeline: LitePipeline) {
self.block.push(pipeline);
}
pub fn is_empty(&self) -> bool {
self.block.is_empty()
}
}
pub fn lite_parse(tokens: &[Token]) -> (LiteBlock, Option<ParseError>) {
let mut block = LiteBlock::new();
let mut curr_pipeline = LitePipeline::new();
let mut curr_command = LiteCommand::new();
let mut last_token = TokenContents::Eol;
let mut last_connector = TokenContents::Pipe;
let mut last_connector_span: Option<Span> = None;
if tokens.is_empty() {
return (LiteBlock::new(), None);
}
let mut curr_comment: Option<Vec<Span>> = None;
let mut error = None;
for token in tokens.iter() {
match &token.contents {
TokenContents::PipePipe => {
error = error.or(Some(ParseError::ShellOrOr(token.span)));
curr_command.push(token.span);
last_token = TokenContents::Item;
}
TokenContents::Item => {
// If we have a comment, go ahead and attach it
if let Some(curr_comment) = curr_comment.take() {
curr_command.comments = curr_comment;
}
curr_command.push(token.span);
last_token = TokenContents::Item;
}
TokenContents::OutGreaterThan
| TokenContents::ErrGreaterThan
| TokenContents::OutErrGreaterThan => {
if !curr_command.is_empty() {
match last_connector {
TokenContents::OutGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
Redirection::Stdout,
curr_command,
));
}
TokenContents::ErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
Redirection::Stderr,
curr_command,
));
}
TokenContents::OutErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
Redirection::StdoutAndStderr,
curr_command,
));
}
_ => {
curr_pipeline
.push(LiteElement::Command(last_connector_span, curr_command));
}
}
curr_command = LiteCommand::new();
}
last_token = token.contents;
last_connector = token.contents;
last_connector_span = Some(token.span);
}
TokenContents::Pipe => {
if !curr_command.is_empty() {
match last_connector {
TokenContents::OutGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
Redirection::Stdout,
curr_command,
));
}
TokenContents::ErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
Redirection::Stderr,
curr_command,
));
}
TokenContents::OutErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
Redirection::StdoutAndStderr,
curr_command,
));
}
_ => {
curr_pipeline
.push(LiteElement::Command(last_connector_span, curr_command));
}
}
curr_command = LiteCommand::new();
}
last_token = TokenContents::Pipe;
last_connector = TokenContents::Pipe;
last_connector_span = Some(token.span);
}
TokenContents::Eol => {
if last_token != TokenContents::Pipe && last_token != TokenContents::OutGreaterThan
{
if !curr_command.is_empty() {
match last_connector {
TokenContents::OutGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span.expect(
"internal error: redirection missing span information",
),
Redirection::Stdout,
curr_command,
));
}
TokenContents::ErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span.expect(
"internal error: redirection missing span information",
),
Redirection::Stderr,
curr_command,
));
}
TokenContents::OutErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span.expect(
"internal error: redirection missing span information",
),
Redirection::StdoutAndStderr,
curr_command,
));
}
_ => {
curr_pipeline
.push(LiteElement::Command(last_connector_span, curr_command));
}
}
curr_command = LiteCommand::new();
}
if !curr_pipeline.is_empty() {
block.push(curr_pipeline);
curr_pipeline = LitePipeline::new();
}
}
if last_token == TokenContents::Eol {
// Clear out the comment as we're entering a new comment
curr_comment = None;
}
last_token = TokenContents::Eol;
}
TokenContents::Semicolon => {
if !curr_command.is_empty() {
match last_connector {
TokenContents::OutGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::Stdout,
curr_command,
));
}
TokenContents::ErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::Stderr,
curr_command,
));
}
TokenContents::OutErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::StdoutAndStderr,
curr_command,
));
}
_ => {
curr_pipeline
.push(LiteElement::Command(last_connector_span, curr_command));
}
}
curr_command = LiteCommand::new();
}
if !curr_pipeline.is_empty() {
block.push(curr_pipeline);
curr_pipeline = LitePipeline::new();
last_connector = TokenContents::Pipe;
last_connector_span = None;
}
last_token = TokenContents::Semicolon;
}
TokenContents::Comment => {
// Comment is beside something
if last_token != TokenContents::Eol {
curr_command.comments.push(token.span);
curr_comment = None;
} else {
// Comment precedes something
if let Some(curr_comment) = &mut curr_comment {
curr_comment.push(token.span);
} else {
curr_comment = Some(vec![token.span]);
}
}
last_token = TokenContents::Comment;
}
}
}
if !curr_command.is_empty() {
match last_connector {
TokenContents::OutGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::Stdout,
curr_command,
));
}
TokenContents::ErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::Stderr,
curr_command,
));
}
TokenContents::OutErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::StdoutAndStderr,
curr_command,
));
}
_ => {
curr_pipeline.push(LiteElement::Command(last_connector_span, curr_command));
}
}
}
if !curr_pipeline.is_empty() {
block.push(curr_pipeline);
}
if last_token == TokenContents::Pipe {
(
block,
Some(ParseError::UnexpectedEof(
"pipeline missing end".into(),
tokens[tokens.len() - 1].span,
)),
)
} else {
(block, error)
}
}