futilehdl/src/parser.rs

142 lines
3.5 KiB
Rust

pub mod error;
pub mod expression;
mod literals;
pub mod module;
pub mod proc;
pub mod tokens;
use nom::{
branch::alt,
bytes::complete::tag,
character::complete::{alpha1, alphanumeric1, multispace0},
combinator::{map, opt, recognize},
error::{ErrorKind, ParseError},
multi::{many0, separated_list0},
sequence::{delimited, pair, preceded, separated_pair, tuple},
};
use nom_greedyerror::GreedyError;
use nom_locate::LocatedSpan;
// custom span type for nom_locate
pub type Span<'a> = LocatedSpan<&'a str>;
pub type IErr<I> = GreedyError<I, ErrorKind>;
// custom IResult type for VerboseError
pub type IResult<I, O, E = IErr<I>> = nom::IResult<I, O, E>;
pub use crate::parser::expression::{expression, Call, Expression, Operation};
pub use crate::parser::module::{module, Module, ModuleItem, PortDirection};
use crate::parser::tokens::{token, TokenKind as tk, TokenSpan};
fn ws0<'a, F: 'a, O, E: ParseError<Span<'a>>>(
inner: F,
) -> impl FnMut(Span<'a>) -> IResult<Span<'a>, O, E>
where
F: FnMut(Span<'a>) -> IResult<Span<'a>, O, E>,
{
delimited(multispace0, inner, multispace0)
}
fn identifier(input: Span) -> IResult<Span, Span> {
recognize(pair(
alt((alpha1, tag("_"))),
many0(alt((alphanumeric1, tag("_")))),
))(input)
}
// TODO: allow recursive generics
// TODO: allow expressions again
fn typename(input: TokenSpan) -> IResult<TokenSpan, TypeName> {
map(
tuple((
token(tk::Ident),
opt(delimited(token(tk::LAngle), expression, token(tk::RAngle))),
)),
|(ident, _)| TypeName {
name: ident.span(),
generics: (),
},
)(input)
}
#[derive(Debug)]
pub struct TypeName<'a> {
name: Span<'a>,
generics: (),
}
#[derive(Debug)]
pub struct NetDecl<'a> {
pub name: Span<'a>,
pub typ: TypeName<'a>,
pub value: Option<Span<'a>>,
}
#[derive(Debug)]
pub struct Assign<'a> {
pub lhs: &'a str,
pub expr: Expression<'a>,
}
fn assign_statement(input: TokenSpan) -> IResult<TokenSpan, Assign> {
map(
separated_pair(token(tk::Ident), token(tk::EqAssign), expression),
|(lhs, expr)| Assign {
lhs: (*lhs.span().fragment()),
expr,
},
)(input)
}
// TODO: reallow assignments
fn declaration(i: TokenSpan) -> IResult<TokenSpan, NetDecl> {
map(
tuple((
separated_pair(token(tk::Ident), token(tk::Colon), typename),
opt(preceded(token(tk::Assign), token(tk::Number))),
)),
|((ident, typ), _value)| NetDecl {
name: ident.span(),
typ,
value: None,
},
)(i)
}
pub fn parse(input: TokenSpan) -> IResult<TokenSpan, Module> {
module(input)
}
#[cfg(test)]
mod test {
use super::*;
use nom::combinator::all_consuming;
#[test]
fn test_operation() {
operation(" a | b ".into()).unwrap();
operation(" a & b ".into()).unwrap();
}
#[test]
fn test_expression() {
expression(" a ".into()).unwrap();
expression(" a | b ".into()).unwrap();
expression(" a | b | c ".into()).unwrap();
}
#[test]
fn test_assignment() {
// TODO: make wrapper and use for all tests
all_consuming(assign_statement)(" a = b ".into()).unwrap();
all_consuming(assign_statement)(" a = b | c ".into()).unwrap();
}
#[test]
fn test_call() {
call_item("thing ( )".into()).unwrap();
call_item("thing ( a , b , c )".into()).unwrap();
call_item("thing(a,b,c)".into()).unwrap();
}
}