From cba23a005cc991e642c834947da87ff6b31638e2 Mon Sep 17 00:00:00 2001
From: unspeaker <hora.nqma@protonmail.com>
Date: Sun, 4 May 2025 19:59:41 +0300
Subject: [PATCH] proc: expose macro implementation

---
 proc/src/lib.rs         |  41 +++--
 proc/src/proc_expose.rs | 392 ++++++++++++++++++++++++++++++++++++++++
 proc/src/proc_view.rs   |  18 +-
 3 files changed, 417 insertions(+), 34 deletions(-)
 create mode 100644 proc/src/proc_expose.rs

diff --git a/proc/src/lib.rs b/proc/src/lib.rs
index 0709e4b..52c8814 100644
--- a/proc/src/lib.rs
+++ b/proc/src/lib.rs
@@ -1,26 +1,31 @@
 extern crate proc_macro;
-use proc_macro::TokenStream;
-use proc_macro2::{TokenStream as TokenStream2};
+
+pub(crate) use std::collections::{HashMap, BTreeMap};
+pub(crate) use std::cmp::Ordering;
+pub(crate) use proc_macro::TokenStream;
+pub(crate) use proc_macro2::{
+    TokenStream as TokenStream2, TokenTree,
+    Ident, Span, Punct, Spacing::*, Group, Delimiter, Literal
+};
+pub(crate) use syn::{
+    parse, parse_macro_input, parse_quote as pq,
+    braced, bracketed, parenthesized, Token,
+    Arm, Expr, Attribute, Meta, MetaList, Path, PathSegment, PathArguments, ImplItem, LitStr, Type,
+    parse::{Parse, ParseStream, Result},
+    token::{PathSep, Brace},
+    punctuated::Punctuated,
+};
+pub(crate) use quote::{quote, TokenStreamExt, ToTokens};
 
 mod proc_view;
+mod proc_expose;
 
 #[proc_macro_attribute]
 pub fn view (meta: TokenStream, item: TokenStream) -> TokenStream {
     self::proc_view::view_impl(meta.into(), item.into()).into()
-    //for attr in syn::parse_macro_input!(meta as syn::MetaList).iter() {
-    //}
-    //let item = syn::parse_macro_input!(item as syn::ItemImpl);
-    //let output = "TuiOut";
-    //let target = "Tek";
-    //let define = "self.config.view";
-    //let expose = vec![];
-    //let output = format!(
-        //"::tengri_dsl::view!({}:|self:{}|self.size.of(::tengri_dsl::View(self,{}));{{{}}});",
-        //output,
-        //target,
-        //define,
-        //expose.iter().fold(String::new(), |acc, (key, value)|format!("{acc},{key}=>{value}")),
-    //);
-    //let output = "";
-    //output.parse().unwrap()
+}
+
+#[proc_macro_attribute]
+pub fn expose (meta: TokenStream, item: TokenStream) -> TokenStream {
+    self::proc_expose::expose_impl(meta.into(), item.into()).into()
 }
diff --git a/proc/src/proc_expose.rs b/proc/src/proc_expose.rs
new file mode 100644
index 0000000..2c34b14
--- /dev/null
+++ b/proc/src/proc_expose.rs
@@ -0,0 +1,392 @@
+use crate::*;
+use syn::parse::discouraged::Speculative;
+
+pub(crate) fn expose_impl (meta: TokenStream, data: TokenStream) -> TokenStream {
+    let mut out = TokenStream2::new();
+    ExposeDefinition {
+        meta: parse_macro_input!(meta as ExposeMeta),
+        data: parse_macro_input!(data as ExposeImpl),
+    }.to_tokens(&mut out);
+    out.into()
+}
+
+#[derive(Debug, Clone)]
+struct ExposeDefinition {
+    meta: ExposeMeta,
+    data: ExposeImpl,
+}
+
+impl Parse for ExposeDefinition {
+    fn parse (input: ParseStream) -> Result<Self> {
+        Ok(Self {
+            meta: input.parse::<ExposeMeta>()?,
+            data: input.parse::<ExposeImpl>()?,
+        })
+    }
+}
+
+impl ToTokens for ExposeDefinition {
+    fn to_tokens (&self, out: &mut TokenStream2) {
+        let Self { meta, data } = self;
+        for token in quote! { #data } {
+            out.append(token)
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+struct ExposeMeta {}
+
+impl Parse for ExposeMeta {
+    fn parse (input: ParseStream) -> Result<Self> {
+        Ok(Self {})
+    }
+}
+
+#[derive(Debug, Clone)]
+struct ExposeImpl {
+    target: Ident,
+    items:  Vec<ImplItem>,
+    types:  BTreeMap<ExposeType, BTreeMap<ExposeSym, ExposeArm>>,
+}
+
+impl Parse for ExposeImpl {
+    fn parse (input: ParseStream) -> Result<Self> {
+        let _impl = input.parse::<Token![impl]>()?;
+        let target = input.parse::<Ident>()?;
+        let group;
+        let brace = braced!(group in input);
+        let mut items = vec![];
+        let mut types: BTreeMap<ExposeType, BTreeMap<ExposeSym, ExposeArm>> = Default::default();
+        while !group.is_empty() {
+            let fork = group.fork();
+            if let Ok(block) = fork.parse::<ExposeBlock>() {
+                let t = block.type_.into();
+                if let Some(values) = types.get_mut(&t) {
+                    for (key, value) in block.values.into_iter() {
+                        if values.contains_key(&key) {
+                            return Err(input.error(format!("{key:?} ({t:?}): already exists")))
+                        } else {
+                            values.insert(key, value);
+                        }
+                    }
+                } else {
+                    types.insert(t, block.values);
+                }
+                group.advance_to(&fork);
+                continue
+            }
+            let fork = group.fork();
+            if let Ok(item) = fork.parse::<ImplItem>() {
+                items.push(item);
+                group.advance_to(&fork);
+                continue
+            }
+            return Err(input.error(
+                "expected either item or #[tengri::expose(type)] { \":key\" => value }"
+            ));
+        }
+        Ok(Self { target, items, types })
+    }
+}
+
+impl ToTokens for ExposeImpl {
+    fn to_tokens (&self, out: &mut TokenStream2) {
+        let Self { target, items, types } = self;
+        for token in quote! { impl #target { #(#items)* } } {
+            out.append(token);
+        }
+        for (t, variants) in types.iter() {
+            let predef = match format!("{}", quote! { #t }).as_str() {
+                "bool" => vec![
+                    quote! { ::tengri::dsl::Value::Sym(":true")  => true  },
+                    quote! { ::tengri::dsl::Value::Sym(":false") => false },
+                ],
+                "u8" | "u16" | "u32" | "u64" | "usize" |
+                "i8" | "i16" | "i32" | "i64" | "isize" => vec![
+                    quote! { ::tengri::dsl::Value::Num(n) => *n },
+                ],
+                _ => vec![],
+            };
+            let values = variants.values();
+            let trait_impl = quote! {
+                impl ::tengri::dsl::Context<#t> for #target {
+                    fn get (&self, dsl: &::tengri::dsl::Value) -> Option<#t> {
+                        Some(match dsl {
+                            #(#predef,)*
+                            #(#values,)*
+                            _ => return None
+                        })
+                    }
+                }
+            };
+            for token in trait_impl {
+                out.append(token);
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+struct ExposeBlock {
+    type_:  Type,
+    values: BTreeMap<ExposeSym, ExposeArm>,
+}
+
+impl Parse for ExposeBlock {
+    fn parse (input: ParseStream) -> Result<Self> {
+        let _ = input.parse::<Token![#]>()?;
+
+        let group;
+        let bracket = bracketed!(group in input);
+        let path = group.parse::<Path>()?;
+        let type_ = if
+            path.segments.get(0).map(|x|x.ident.to_string()) == Some("tengri".to_string()) &&
+            path.segments.get(1).map(|x|x.ident.to_string()) == Some("expose".to_string()) 
+        {
+            let token;
+            let paren = parenthesized!(token in group);
+            token.parse::<Type>()?
+        } else {
+            return Err(input.error("expected #[tengri::expose(type)]"))
+        };
+
+        let group;
+        let brace = braced!(group in input);
+        let mut values = BTreeMap::new();
+        while !group.is_empty() {
+            let arm = group.parse::<ExposeArm>()?;
+            values.insert(arm.key.clone(), arm);
+            let _ = group.parse::<Token![,]>()?;
+        }
+        Ok(Self { type_, values })
+    }
+}
+
+#[derive(Debug, Clone)]
+struct ExposeArm {
+    key:   ExposeSym,
+    value: Expr
+}
+
+impl Parse for ExposeArm {
+    fn parse (input: ParseStream) -> Result<Self> {
+        let key = input.parse::<LitStr>()?.into();
+        let _ = input.parse::<Token![=]>()?;
+        let _ = input.parse::<Token![>]>()?;
+        let value = input.parse::<Expr>()?;
+        Ok(Self { key, value })
+    }
+}
+
+impl ToTokens for ExposeArm {
+    fn to_tokens (&self, out: &mut TokenStream2) {
+        let Self { key, value } = self;
+        out.append(Punct::new(':', Joint));
+        out.append(Punct::new(':', Alone));
+        out.append(Ident::new("tengri", Span::call_site()));
+        out.append(Punct::new(':', Joint));
+        out.append(Punct::new(':', Alone));
+        out.append(Ident::new("dsl", Span::call_site()));
+        out.append(Punct::new(':', Joint));
+        out.append(Punct::new(':', Alone));
+        out.append(Ident::new("Value", Span::call_site()));
+        out.append(Punct::new(':', Joint));
+        out.append(Punct::new(':', Alone));
+        out.append(Ident::new("Sym", Span::call_site()));
+        out.append(Group::new(Delimiter::Parenthesis, {
+            let mut out = TokenStream2::new();
+            out.append(key.0.token());
+            out
+        }));
+        out.append(Punct::new('=', Joint));
+        out.append(Punct::new('>', Alone));
+        for token in quote! { #value } {
+            out.append(token);
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+struct ExposeSym(LitStr);
+
+impl From<LitStr> for ExposeSym {
+    fn from (this: LitStr) -> Self {
+        Self(this)
+    }
+}
+
+impl PartialOrd for ExposeSym {
+    fn partial_cmp (&self, other: &Self) -> Option<Ordering> {
+        let this = &self.0;
+        let that = &other.0;
+        Some(format!("{}", quote! { #this }).cmp(&format!("{}", quote! { #that })))
+    }
+}
+
+impl Ord for ExposeSym {
+    fn cmp (&self, other: &Self) -> Ordering {
+        let this = &self.0;
+        let that = &other.0;
+        format!("{}", quote! { #this }).cmp(&format!("{}", quote! { #that }))
+    }
+}
+
+impl PartialEq for ExposeSym {
+    fn eq (&self, other: &Self) -> bool {
+        let this = &self.0;
+        let that = &other.0;
+        format!("{}", quote! { #this }) == format!("{}", quote! { #that })
+    }
+}
+
+impl Eq for ExposeSym {}
+
+#[derive(Debug, Clone)]
+struct ExposeType(Type);
+
+impl From<Type> for ExposeType {
+    fn from (this: Type) -> Self {
+        Self(this)
+    }
+}
+
+impl PartialOrd for ExposeType {
+    fn partial_cmp (&self, other: &Self) -> Option<Ordering> {
+        let this = &self.0;
+        let that = &other.0;
+        Some(format!("{}", quote! { #this }).cmp(&format!("{}", quote! { #that })))
+    }
+}
+
+impl Ord for ExposeType {
+    fn cmp (&self, other: &Self) -> Ordering {
+        let this = &self.0;
+        let that = &other.0;
+        format!("{}", quote! { #this }).cmp(&format!("{}", quote! { #that }))
+    }
+}
+
+impl PartialEq for ExposeType {
+    fn eq (&self, other: &Self) -> bool {
+        let this = &self.0;
+        let that = &other.0;
+        format!("{}", quote! { #this }) == format!("{}", quote! { #that })
+    }
+}
+
+impl Eq for ExposeType {}
+
+impl ToTokens for ExposeType {
+    fn to_tokens (&self, out: &mut TokenStream2) {
+        self.0.to_tokens(out)
+    }
+}
+
+#[cfg(test)] #[test] fn test_expose_definition () {
+    let parsed: ExposeImpl = pq! {
+        //#[tengri_proc::expose]
+        impl Something {
+            #[tengri::expose(bool)] {
+                ":bool1" => true || false,
+            }
+            fn something () {}
+        }
+    };
+    // FIXME:
+    //assert_eq!(
+        //format!("{}", quote! { #parsed }),
+        //format!("{}", quote! {
+            //impl Something {
+                //fn something () {}
+            //}
+            //impl ::tengri::Context<bool> for Something {
+                //fn get (&self, dsl: &::tengri::Value) -> Option<bool> {
+                    //Some(match dsl {
+                        //::tengri::Value::Sym(":true")  => true,
+                        //::tengri::Value::Sym(":false") => false,
+                        //::tengri::Value::Sym(":bool1") => true || false,
+                        //_ => return None
+                    //})
+                //}
+            //}
+        //})
+    //);
+
+    let parsed: ExposeImpl = pq! {
+        //#[tengri_proc::expose]
+        impl Something {
+            #[tengri::expose(bool)] {
+                ":bool1" => true || false,
+            }
+            #[tengri::expose(u16)] {
+                ":u161" => 0 + 1,
+            }
+            #[tengri::expose(usize)] {
+                ":usize1" => 1 + 2,
+            }
+            #[tengri::expose(Arc<str>)] {
+                ":arcstr1" => "foo".into(),
+            }
+            #[tengri::expose(Option<Arc<str>>)] {
+                ":optarcstr1" => Some("bar".into()),
+                ":optarcstr2" => Some("baz".into()),
+            }
+            fn something () {}
+        }
+    };
+    // FIXME:
+    //assert_eq!(
+        //format!("{}", quote! { #parsed }),
+        //format!("{}", quote! {
+            //impl Something {
+                //fn something () {}
+            //}
+            //impl ::tengri::Context<Arc<str>> for Something {
+                //fn get (&self, dsl: &::tengri::Value) -> Option<Arc<str>> {
+                    //Some(match dsl {
+                        //::tengri::Value::Sym(":arcstr1") => "foo".into(),
+                        //_ => return None
+                    //})
+                //}
+            //}
+            //impl ::tengri::Context<Option<Arc<str>>> for Something {
+                //fn get (&self, dsl: &::tengri::Value) -> Option<Option<Arc<str>>> {
+                    //Some(match dsl {
+                        //::tengri::Value::Sym(":optarcstr1") => Some("bar".into()),
+                        //::tengri::Value::Sym(":optarcstr2") => Some("baz".into()),
+                        //_ => return None
+                    //})
+                //}
+            //}
+            //impl ::tengri::Context<bool> for Something {
+                //fn get (&self, dsl: &::tengri::Value) -> Option<bool> {
+                    //Some(match dsl {
+                        //::tengri::Value::Sym(":true")  => true,
+                        //::tengri::Value::Sym(":false") => false,
+                        //::tengri::Value::Sym(":bool1") => true || false,
+                        //_ => return None
+                    //})
+                //}
+            //}
+            //impl ::tengri::Context<u16> for Something {
+                //fn get (&self, dsl: &::tengri::Value) -> Option<u16> {
+                    //Some(match dsl {
+                        //::tengri::Value::Num(n) => *n as u16,
+                        //::tengri::Value::Sym(":u161") => 0 + 1,
+                        //_ => return None
+                    //})
+                //}
+            //}
+            //impl ::tengri::Context<usize> for Something {
+                //fn get (&self, dsl: &::tengri::Value) -> Option<usize> {
+                    //Some(match dsl {
+                        //::tengri::Value::Num(n) => *n as usize,
+                        //::tengri::Value::Sym(":usize1") => 1 + 2,
+                        //_ => return None
+                    //})
+                //}
+            //}
+        //})
+    //)
+}
diff --git a/proc/src/proc_view.rs b/proc/src/proc_view.rs
index 7095fce..2a32d27 100644
--- a/proc/src/proc_view.rs
+++ b/proc/src/proc_view.rs
@@ -1,14 +1,4 @@
-use proc_macro::TokenStream;
-use proc_macro2::{
-    TokenStream as TokenStream2, TokenTree,
-    Ident, Span, Punct, Spacing, Group, Delimiter, Literal
-};
-use syn::{parse, parse_macro_input, braced, Token};
-use syn::{Expr, Attribute, Meta, MetaList, Path, PathSegment, PathArguments, ImplItem, LitStr};
-use syn::parse::{Parse, ParseStream, Result};
-use syn::token::{PathSep, Brace};
-use syn::punctuated::Punctuated;
-use quote::{quote, TokenStreamExt, ToTokens};
+use crate::*;
 
 pub(crate) fn view_impl (meta: TokenStream, data: TokenStream) -> TokenStream {
     let mut out = TokenStream2::new();
@@ -28,7 +18,6 @@ struct ViewDefinition {
 #[derive(Debug, Clone)]
 struct ViewMeta {
     output: Ident,
-    //attrs:  Vec<Attribute>,
 }
 
 #[derive(Debug, Clone)]
@@ -70,7 +59,7 @@ impl Parse for ViewMeta {
 impl Parse for ViewImpl {
     fn parse (input: ParseStream) -> Result<Self> {
         let _ = input.parse::<Token![impl]>()?;
-        let mut syms  = vec![];
+        let mut syms = vec![];
         Ok(Self {
             target: input.parse::<Ident>()?,
             items: {
@@ -131,7 +120,6 @@ impl Parse for ViewItem {
 
 impl ToTokens for ViewSym {
     fn to_tokens (&self, out: &mut TokenStream2) {
-        use Spacing::*;
         out.append(Punct::new(':', Joint));
         out.append(Punct::new(':', Alone));
         out.append(Ident::new("tengri", Span::call_site()));
@@ -226,8 +214,6 @@ impl std::cmp::PartialEq for ViewSym {
     }
 }
 
-#[cfg(test)] use syn::{ItemImpl, parse_quote as pq};
-
 #[cfg(test)] #[test] fn test_view_meta () {
     let x: ViewMeta   = pq! { SomeOutput };
     let output: Ident = pq! { SomeOutput };