Grcov report - forms.rs

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//! Reader macros for quote / quasiquote / unquote / unquote-splicing

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//! plus the parenthesised list parser (including the dotted-pair tail

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//! `(a . b)` form).

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5

use winnow::combinator::cut_err;

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use winnow::error::{AddContext, ContextError, ErrMode, ModalResult, StrContext, StrContextValue};

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use winnow::prelude::*;

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use crate::ast::Expr;

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use super::parse_expr;

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use super::whitespace::skip_ws_and_comments_no_annotations;

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6275804

pub(super) fn parse_quote(input: &mut &str) -> ModalResult<Expr> {

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6275804

    let _ = '\''.parse_next(input)?;

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45731

    let expr = parse_expr.parse_next(input)?;

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45731

    Ok(Expr::Quote(Box::new(expr)))

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6275804

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6230073

pub(super) fn parse_quasiquote(input: &mut &str) -> ModalResult<Expr> {

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6230073

    let _ = '`'.parse_next(input)?;

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1423

    let expr = parse_expr.parse_next(input)?;

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1423

    Ok(Expr::Quasiquote(Box::new(expr)))

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6230073

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6228650

pub(super) fn parse_unquote(input: &mut &str) -> ModalResult<Expr> {

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6228650

    let _ = ','.parse_next(input)?;

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1566

    if input.starts_with('@') {

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214

        let _ = '@'.parse_next(input)?;

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214

        let expr = parse_expr.parse_next(input)?;

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214

        return Ok(Expr::UnquoteSplicing(Box::new(expr)));

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1352

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1352

    let expr = parse_expr.parse_next(input)?;

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1352

    Ok(Expr::Unquote(Box::new(expr)))

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6228650

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6227084

pub(super) fn parse_list(input: &mut &str) -> ModalResult<Expr> {

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6227084

    let _ = '('.parse_next(input)?;

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2394594

    skip_ws_and_comments_no_annotations(input)?;

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2394594

    let mut items = Vec::new();

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2394594

    let mut dotted_cdr: Option<Expr> = None;

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    loop {

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8390536

        if input.starts_with(')') {

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2392813

            break;

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5997723

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5997723

        if input.is_empty() {

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923

            return Err(ErrMode::Cut(

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923

                ContextError::new()

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923

                    .add_context(input, &input.checkpoint(), StrContext::Label("list"))

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923

                    .add_context(

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923

                        input,

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923

                        &input.checkpoint(),

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923

                        StrContext::Expected(StrContextValue::Description("closing paren")),

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923

),

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923

));

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5996800

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5996800

        if input.starts_with('.') && input.chars().nth(1).is_some_and(char::is_whitespace) {

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6

            let _ = '.'.parse_next(input)?;

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6

            skip_ws_and_comments_no_annotations(input)?;

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6

            dotted_cdr = Some(

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6

                cut_err(parse_expr)

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6

                    .context(StrContext::Label("cdr expression"))

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6

                    .parse_next(input)?,

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);

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6

            skip_ws_and_comments_no_annotations(input)?;

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6

            cut_err(')')

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6

                .context(StrContext::Label("closing paren"))

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6

                .context(StrContext::Expected(StrContextValue::Description(

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6

                    "only one expression after dot in dotted pair",

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6

)))

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6

                .parse_next(input)?;

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5

            break;

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5996794

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5996794

        let expr = parse_expr(input)?;

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5995942

        items.push(expr);

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5995942

        skip_ws_and_comments_no_annotations(input)?;

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2392818

    if dotted_cdr.is_none() {

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2392813

        cut_err(')')

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2392813

            .context(StrContext::Label("list"))

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2392813

            .context(StrContext::Expected(StrContextValue::Description(

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2392813

                "closing paren",

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2392813

)))

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2392813

            .parse_next(input)?;

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5

89

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2392818

    if let Some(cdr) = dotted_cdr {

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5

        let mut result = cdr;

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6

        for item in items.into_iter().rev() {

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6

            result = Expr::cons(item, result);

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6

95

5

        Ok(result)

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    } else {

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2392813

        Ok(Expr::List(items))

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6227084