| 1 | use crate::token::{Id, Index}; |
|---|---|
| 2 | use crate::Error; |
| 3 | use std::collections::HashMap; |
| 4 | |
| 5 | #[derive(Default)] |
| 6 | pub struct Namespace<'a> { |
| 7 | names: HashMap<Id<'a>, u32>, |
| 8 | count: u32, |
| 9 | } |
| 10 | |
| 11 | impl<'a> Namespace<'a> { |
| 12 | pub fn register(&mut self, name: Option<Id<'a>>, desc: &str) -> Result<u32, Error> { |
| 13 | let index = self.alloc(); |
| 14 | if let Some(name) = name { |
| 15 | if let Some(_prev) = self.names.insert(name, index) { |
| 16 | return Err(Error::new( |
| 17 | name.span(), |
| 18 | format!("duplicate{} identifier", desc), |
| 19 | )); |
| 20 | } |
| 21 | } |
| 22 | Ok(index) |
| 23 | } |
| 24 | |
| 25 | pub fn alloc(&mut self) -> u32 { |
| 26 | let index = self.count; |
| 27 | self.count += 1; |
| 28 | index |
| 29 | } |
| 30 | |
| 31 | pub fn register_specific(&mut self, name: Id<'a>, index: u32, desc: &str) -> Result<(), Error> { |
| 32 | if let Some(_prev) = self.names.insert(name, index) { |
| 33 | return Err(Error::new( |
| 34 | name.span(), |
| 35 | format!( |
| 36 | "duplicate identifier: duplicate{desc} named `{} `", |
| 37 | name.name() |
| 38 | ), |
| 39 | )); |
| 40 | } |
| 41 | Ok(()) |
| 42 | } |
| 43 | |
| 44 | pub fn resolve(&self, idx: &mut Index<'a>, desc: &str) -> Result<u32, Error> { |
| 45 | let id = match idx { |
| 46 | Index::Num(n, _) => return Ok(*n), |
| 47 | Index::Id(id) => id, |
| 48 | }; |
| 49 | if let Some(&n) = self.names.get(id) { |
| 50 | *idx = Index::Num(n, id.span()); |
| 51 | return Ok(n); |
| 52 | } |
| 53 | Err(resolve_error(*id, desc)) |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | pub fn resolve_error(id: Id<'_>, ns: &str) -> Error { |
| 58 | assert!( |
| 59 | !id.is_gensym(), |
| 60 | "symbol generated by `wast` itself cannot be resolved{:?} ", |
| 61 | id |
| 62 | ); |
| 63 | Error::new( |
| 64 | id.span(), |
| 65 | message:format!("unknown{ns} : failed to find name `${} `", id.name()), |
| 66 | ) |
| 67 | } |
| 68 |