Output Rust code using `syn`

finchie

Oct 26, 2023, 8:14 AM

BA5Y6VSEHJQBOYBS6R6FE6IZDRNAPNIN5ITJXWK7L46RJVHNI7JAC

Dependencies

• [2] 2N3KOCP7 Create MVP Pandoc->Rust compiler
• [*] C73UJ7ZY Create simple `xilem_html` demo

Change contents

• edit in Cargo.lock at line 422
  [2.1000]

  [2.1000]
  + "proc-macro2",

  + "quote",

  + "syn",
• edit in crates/typst_rust_gen/src/lib.rs at line 2
  [2.1232]

  [2.1232]
  +

  + use pandoc::PandocOutput;

  + use quote::quote;

  + use syn::punctuated::Punctuated;
• replacement in crates/typst_rust_gen/src/lib.rs at line 7
  [2.1233]→[2.1233:1308](∅→∅)
  − use pandoc::{OutputFormat, PandocOutput};

  − use pandoc_ast::{Block, Inline};
  [2.1233]

  [2.1308]
  + // Safely wrap i64 header levels in an enum

  + enum HeaderLevel {

  + H1,

  + H2,

  + H3,

  + H4,

  + H5,

  + H6,

  + }

  +

  + // This is not TryFrom as there's not really much we can do to handle the error?

  + impl From<i64> for HeaderLevel {

  + fn from(value: i64) -> Self {

  + match value {

  + 1 => HeaderLevel::H1,

  + 2 => HeaderLevel::H2,

  + 3 => HeaderLevel::H3,

  + 4 => HeaderLevel::H4,

  + 5 => HeaderLevel::H5,

  + 6 => HeaderLevel::H6,

  + _ => panic!(

  + "Unexpected header level! Headers must be in range of 1 to 6 (inclusive), got: {}",

  + value

  + ),

  + }

  + }

  + }

  +

  + impl From<HeaderLevel> for &str {

  + fn from(value: HeaderLevel) -> Self {

  + match value {

  + HeaderLevel::H1 => "h1",

  + HeaderLevel::H2 => "h2",

  + HeaderLevel::H3 => "h3",

  + HeaderLevel::H4 => "h4",

  + HeaderLevel::H5 => "h5",

  + HeaderLevel::H6 => "h6",

  + }

  + }

  + }

  +

  + struct ElementBlock<'a> {

  + name: &'a str,

  + expression: syn::Expr,

  + }

  +

  + impl ElementBlock<'_> {

  + fn method_call(self) -> syn::Expr {

  + let mut args: Punctuated<syn::Expr, syn::token::Comma> = Punctuated::new();

  + args.push(self.expression);
• edit in crates/typst_rust_gen/src/lib.rs at line 58
  [2.1309]

  [2.1309]
  + let expr_call = syn::ExprCall {

  + attrs: Vec::new(),

  + func: Box::new(expr_path(self.name)),

  + paren_token: syn::token::Paren::default(),

  + args,

  + };

  + syn::Expr::Call(expr_call)

  + }

  + }

  +
• replacement in crates/typst_rust_gen/src/lib.rs at line 72
  [2.1423]→[2.1423:1485](∅→∅)
  − pandoc.set_output_format(OutputFormat::Json, Vec::new());
  [2.1423]

  [2.1485]
  + pandoc.set_output_format(pandoc::OutputFormat::Json, Vec::new());
• edit in crates/typst_rust_gen/src/lib.rs at line 82
  [2.1781]

  [2.1781]
  +

  + let blocks: Vec<syn::Expr> = ast.blocks.iter().map(transform_block).collect();

  + dbg!(&blocks, blocks.len());
• replacement in crates/typst_rust_gen/src/lib.rs at line 86
  [2.1782]→[2.1782:1947](∅→∅)
  − let blocks: String = ast

  − .blocks

  − .iter()

  − .map(transform_block)

  − .collect::<Vec<String>>()

  − .join(", ");

  − dbg!(&blocks);
  [2.1782]

  [2.1947]
  + let file = syn::File {

  + shebang: None,

  + attrs: Vec::new(),

  + items: vec![syn::Item::Fn(syn::ItemFn {

  + attrs: Vec::new(),

  + vis: syn::Visibility::Public(syn::token::Pub::default()),

  + sig: syn::Signature {

  + constness: None,

  + asyncness: None,

  + unsafety: None,

  + abi: None,

  + fn_token: syn::token::Fn::default(),

  + ident: syn::Ident::new("test", proc_macro2::Span::call_site()),

  + generics: syn::Generics::default(),

  + paren_token: syn::token::Paren::default(),

  + inputs: Punctuated::new(),

  + variadic: None,

  + output: syn::ReturnType::Default,

  + },

  + block: Box::new(syn::Block {

  + brace_token: syn::token::Brace::default(),

  + stmts: vec![syn::Stmt::Expr(

  + syn::Expr::Tuple(syn::ExprTuple {

  + attrs: Vec::new(),

  + paren_token: syn::token::Paren::default(),

  + elems: Punctuated::from_iter(blocks.into_iter()),

  + }),

  + None,

  + )],

  + }),

  + })],

  + };

  +

  + quote!(#file).to_string()

  + }

  +

  + fn path_segment(segment: &str) -> syn::PathSegment {

  + syn::PathSegment {

  + ident: syn::Ident::new(segment, proc_macro2::Span::call_site()),

  + arguments: syn::PathArguments::None,

  + }

  + }

  +

  + fn expr_path(name: &str) -> syn::Expr {

  + let mut segments: Punctuated<syn::PathSegment, syn::token::PathSep> = Punctuated::new();
• replacement in crates/typst_rust_gen/src/lib.rs at line 132
  [2.1948]→[2.1948:1959](∅→∅)
  − blocks
  [2.1948]

  [2.1959]
  + // The path should be el::name

  + // e.g. el::h2

  + segments.push(path_segment("el"));

  + segments.push(path_segment(name));

  +

  + let expr_path = syn::ExprPath {

  + attrs: Vec::new(),

  + qself: None,

  + path: syn::Path {

  + leading_colon: None,

  + segments,

  + },

  + };

  +

  + syn::Expr::Path(expr_path)
• replacement in crates/typst_rust_gen/src/lib.rs at line 149
  [2.1962]→[2.1962:2076](∅→∅)
  − fn transform_block(block: &Block) -> String {

  − match block {

  − Block::Header(level, _attr, inlines) => {
  [2.1962]

  [2.2076]
  + fn transform_block(block: &pandoc_ast::Block) -> syn::Expr {

  + let block = match block {

  + pandoc_ast::Block::Header(level, _attr, inlines) => {
• edit in crates/typst_rust_gen/src/lib.rs at line 153
  [2.2142]

  [2.2142]
  + let header_level = HeaderLevel::from(*level);
• replacement in crates/typst_rust_gen/src/lib.rs at line 155
  [2.2143]→[2.2143:2211](∅→∅)
  − format!(r#"el::h{}("{}")"#, level, transformed_inlines)
  [2.2143]

  [2.2211]
  + ElementBlock {

  + name: header_level.into(),

  + expression: transformed_inlines,

  + }
• replacement in crates/typst_rust_gen/src/lib.rs at line 160
  [2.2221]→[2.2221:2255](∅→∅)
  − Block::Para(inlines) => {
  [2.2221]

  [2.2255]
  + pandoc_ast::Block::Para(inlines) => {
• replacement in crates/typst_rust_gen/src/lib.rs at line 162
  [2.2321]→[2.2321:2380](∅→∅)
  − format!(r#"el::p("{}")"#, transformed_inlines)
  [2.2321]

  [2.2380]
  + ElementBlock {

  + name: "p",

  + expression: transformed_inlines,

  + }
• replacement in crates/typst_rust_gen/src/lib.rs at line 168
  [2.2412]→[2.2412:2418](∅→∅)
  − }
  [2.2412]

  [2.2418]
  + };

  +

  + block.method_call()
• replacement in crates/typst_rust_gen/src/lib.rs at line 173
  [2.2421]→[2.2421:2470](∅→∅)
  − fn transform_inline(inline: &Inline) -> String {
  [2.2421]

  [2.2470]
  + fn transform_inline(inline: &pandoc_ast::Inline) -> &str {
• replacement in crates/typst_rust_gen/src/lib.rs at line 175
  [2.2489]→[2.2489:2579](∅→∅)
  − Inline::Str(text) => text.to_owned(),

  − Inline::Space => String::from(" "),
  [2.2489]

  [2.2579]
  + pandoc_ast::Inline::Str(text) => text,

  + pandoc_ast::Inline::Space => " ",
• replacement in crates/typst_rust_gen/src/lib.rs at line 181
  [2.2610]→[2.2610:2784](∅→∅)
  − fn transform_inlines(inlines: &Vec<Inline>) -> String {

  − let transformed: String = inlines.iter().map(transform_inline).collect();

  − dbg!(&transformed);

  − transformed
  [2.2610]

  [2.2784]
  + fn transform_inlines(inlines: &Vec<pandoc_ast::Inline>) -> syn::Expr {

  + let transformed: Vec<&str> = inlines.iter().map(transform_inline).collect();

  + let full_literal: String = transformed.join("");

  +

  + dbg!(&full_literal);

  + // TODO: figure out what the span actually should be

  + let lit_str = syn::LitStr::new(&full_literal, proc_macro2::Span::call_site());

  + syn::Expr::Lit(syn::ExprLit {

  + attrs: Vec::new(),

  + lit: syn::Lit::Str(lit_str),

  + })
• edit in crates/typst_rust_gen/Cargo.toml at line 9
  [2.3134]
  + proc-macro2 = "1.0.69"

  + quote = "1.0.33"

  + syn = { version = "2.0.38", features = ["full", "extra-traits"] }