Merge #3909

3909: Generate tokense r=matklad a=matklad

bors r+
🤖

Co-authored-by: Luca Barbieri <luca@luca-barbieri.com>
Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>

crates/ra_syntax/src/ast.rs

@@ -30,7 +30,7 @@ pub use self::{
 /// conversion itself has zero runtime cost: ast and syntax nodes have exactly
 /// the same representation: a pointer to the tree root and a pointer to the
 /// node itself.
-pub trait AstNode: std::fmt::Display {
+pub trait AstNode {
     fn can_cast(kind: SyntaxKind) -> bool
     where
         Self: Sized;
@@ -49,10 +49,16 @@ fn assert_ast_is_object_safe() {
 
 /// Like `AstNode`, but wraps tokens rather than interior nodes.
 pub trait AstToken {
-    fn cast(token: SyntaxToken) -> Option<Self>
+    fn can_cast(token: SyntaxKind) -> bool
     where
         Self: Sized;
+
+    fn cast(syntax: SyntaxToken) -> Option<Self>
+    where
+        Self: Sized;
+
     fn syntax(&self) -> &SyntaxToken;
+
     fn text(&self) -> &SmolStr {
         self.syntax().text()
     }

crates/ra_syntax/src/ast/tokens.rs

@@ -1,26 +1,10 @@
 //! There are many AstNodes, but only a few tokens, so we hand-write them here.
 
 use crate::{
-    ast::AstToken,
+    ast::{AstToken, Comment, RawString, String, Whitespace},
-    SyntaxKind::{COMMENT, RAW_STRING, STRING, WHITESPACE},
+    TextRange, TextUnit,
-    SyntaxToken, TextRange, TextUnit,
 };
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct Comment(SyntaxToken);
-
-impl AstToken for Comment {
-    fn cast(token: SyntaxToken) -> Option<Self> {
-        match token.kind() {
-            COMMENT => Some(Comment(token)),
-            _ => None,
-        }
-    }
-    fn syntax(&self) -> &SyntaxToken {
-        &self.0
-    }
-}
-
 impl Comment {
     pub fn kind(&self) -> CommentKind {
         kind_by_prefix(self.text())
@@ -89,20 +73,6 @@ fn prefix_by_kind(kind: CommentKind) -> &'static str {
     unreachable!()
 }
 
-pub struct Whitespace(SyntaxToken);
-
-impl AstToken for Whitespace {
-    fn cast(token: SyntaxToken) -> Option<Self> {
-        match token.kind() {
-            WHITESPACE => Some(Whitespace(token)),
-            _ => None,
-        }
-    }
-    fn syntax(&self) -> &SyntaxToken {
-        &self.0
-    }
-}
-
 impl Whitespace {
     pub fn spans_multiple_lines(&self) -> bool {
         let text = self.text();
@@ -168,20 +138,6 @@ pub trait HasStringValue: HasQuotes {
     fn value(&self) -> Option<std::string::String>;
 }
 
-pub struct String(SyntaxToken);
-
-impl AstToken for String {
-    fn cast(token: SyntaxToken) -> Option<Self> {
-        match token.kind() {
-            STRING => Some(String(token)),
-            _ => None,
-        }
-    }
-    fn syntax(&self) -> &SyntaxToken {
-        &self.0
-    }
-}
-
 impl HasStringValue for String {
     fn value(&self) -> Option<std::string::String> {
         let text = self.text().as_str();
@@ -201,20 +157,6 @@ impl HasStringValue for String {
     }
 }
 
-pub struct RawString(SyntaxToken);
-
-impl AstToken for RawString {
-    fn cast(token: SyntaxToken) -> Option<Self> {
-        match token.kind() {
-            RAW_STRING => Some(RawString(token)),
-            _ => None,
-        }
-    }
-    fn syntax(&self) -> &SyntaxToken {
-        &self.0
-    }
-}
-
 impl HasStringValue for RawString {
     fn value(&self) -> Option<std::string::String> {
         let text = self.text().as_str();

xtask/src/codegen/gen_syntax.rs

@@ -5,6 +5,8 @@
 
 use proc_macro2::{Punct, Spacing};
 use quote::{format_ident, quote};
+use std::borrow::Cow;
+use std::collections::{BTreeSet, HashMap, HashSet};
 
 use crate::{
     ast_src::{AstSrc, FieldSrc, KindsSrc, AST_SRC, KINDS_SRC},
@@ -18,13 +20,108 @@ pub fn generate_syntax(mode: Mode) -> Result<()> {
     update(syntax_kinds_file.as_path(), &syntax_kinds, mode)?;
 
     let ast_file = project_root().join(codegen::AST);
-    let ast = generate_ast(AST_SRC)?;
+    let ast = generate_ast(KINDS_SRC, AST_SRC)?;
     update(ast_file.as_path(), &ast, mode)?;
 
     Ok(())
 }
 
-fn generate_ast(grammar: AstSrc<'_>) -> Result<String> {
+#[derive(Debug, Default, Clone)]
+struct ElementKinds {
+    kinds: BTreeSet<proc_macro2::Ident>,
+    has_nodes: bool,
+    has_tokens: bool,
+}
+
+fn generate_ast(kinds: KindsSrc<'_>, grammar: AstSrc<'_>) -> Result<String> {
+    let all_token_kinds: Vec<_> = kinds
+        .punct
+        .into_iter()
+        .map(|(_, kind)| kind)
+        .copied()
+        .map(|x| x.into())
+        .chain(
+            kinds
+                .keywords
+                .into_iter()
+                .chain(kinds.contextual_keywords.into_iter())
+                .map(|name| Cow::Owned(format!("{}_KW", to_upper_snake_case(&name)))),
+        )
+        .chain(kinds.literals.into_iter().copied().map(|x| x.into()))
+        .chain(kinds.tokens.into_iter().copied().map(|x| x.into()))
+        .collect();
+
+    let mut element_kinds_map = HashMap::new();
+    for kind in &all_token_kinds {
+        let kind = &**kind;
+        let name = to_pascal_case(kind);
+        element_kinds_map.insert(
+            name,
+            ElementKinds {
+                kinds: Some(format_ident!("{}", kind)).into_iter().collect(),
+                has_nodes: false,
+                has_tokens: true,
+            },
+        );
+    }
+
+    for kind in kinds.nodes {
+        let name = to_pascal_case(kind);
+        element_kinds_map.insert(
+            name,
+            ElementKinds {
+                kinds: Some(format_ident!("{}", *kind)).into_iter().collect(),
+                has_nodes: true,
+                has_tokens: false,
+            },
+        );
+    }
+
+    for en in grammar.enums {
+        let mut element_kinds: ElementKinds = Default::default();
+        for variant in en.variants {
+            if let Some(variant_element_kinds) = element_kinds_map.get(*variant) {
+                element_kinds.kinds.extend(variant_element_kinds.kinds.iter().cloned());
+                element_kinds.has_tokens |= variant_element_kinds.has_tokens;
+                element_kinds.has_nodes |= variant_element_kinds.has_nodes;
+            } else {
+                panic!("Enum variant has type that does not exist or was not declared before the enum: {}", *variant);
+            }
+        }
+        element_kinds_map.insert(en.name.to_string(), element_kinds);
+    }
+
+    let tokens = all_token_kinds.iter().map(|kind_str| {
+        let kind_str = &**kind_str;
+        let kind = format_ident!("{}", kind_str);
+        let name = format_ident!("{}", to_pascal_case(kind_str));
+        quote! {
+            #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+            pub struct #name {
+                pub(crate) syntax: SyntaxToken,
+            }
+
+            impl std::fmt::Display for #name {
+                fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+                    std::fmt::Display::fmt(&self.syntax, f)
+                }
+            }
+
+            impl AstToken for #name {
+                fn can_cast(kind: SyntaxKind) -> bool {
+                    match kind {
+                        #kind => true,
+                        _ => false,
+                    }
+                }
+                fn cast(syntax: SyntaxToken) -> Option<Self> {
+                    if Self::can_cast(syntax.kind()) { Some(Self { syntax }) } else { None }
+                }
+                fn syntax(&self) -> &SyntaxToken { &self.syntax }
+            }
+        }
+    });
+
     let nodes = grammar.nodes.iter().map(|node| {
         let name = format_ident!("{}", node.name);
         let kind = format_ident!("{}", to_upper_snake_case(&name.to_string()));
@@ -42,6 +139,7 @@ fn generate_ast(grammar: AstSrc<'_>) -> Result<String> {
                 FieldSrc::Optional(ty) | FieldSrc::Many(ty) => ty,
                 FieldSrc::Shorthand => name,
             };
+
             let ty = format_ident!("{}", ty);
 
             match field {
@@ -86,6 +184,7 @@ fn generate_ast(grammar: AstSrc<'_>) -> Result<String> {
                 }
                 fn syntax(&self) -> &SyntaxNode { &self.syntax }
             }
+
             #(#traits)*
 
             impl #name {
@@ -154,12 +253,25 @@ fn generate_ast(grammar: AstSrc<'_>) -> Result<String> {
         }
     });
 
+    let defined_nodes: HashSet<_> = grammar.nodes.iter().map(|node| node.name).collect();
+
+    for node in kinds
+        .nodes
+        .iter()
+        .map(|kind| to_pascal_case(*kind))
+        .filter(|name| !defined_nodes.contains(&**name))
+    {
+        eprintln!("Warning: node {} not defined in ast source", node);
+    }
+
     let ast = quote! {
+        #[allow(unused_imports)]
         use crate::{
-            SyntaxNode, SyntaxKind::{self, *},
+            SyntaxNode, SyntaxToken, SyntaxElement, NodeOrToken, SyntaxKind::{self, *},
-            ast::{self, AstNode, AstChildren},
+            ast::{self, AstNode, AstToken, AstChildren},
         };
 
+        #(#tokens)*
         #(#nodes)*
         #(#enums)*
     };
@@ -282,12 +394,12 @@ fn generate_syntax_kinds(grammar: KindsSrc<'_>) -> Result<String> {
 
 fn to_upper_snake_case(s: &str) -> String {
     let mut buf = String::with_capacity(s.len());
-    let mut prev_is_upper = None;
+    let mut prev = false;
     for c in s.chars() {
-        if c.is_ascii_uppercase() && prev_is_upper == Some(false) {
+        if c.is_ascii_uppercase() && prev {
             buf.push('_')
         }
-        prev_is_upper = Some(c.is_ascii_uppercase());
+        prev = true;
 
         buf.push(c.to_ascii_uppercase());
     }
@@ -296,14 +408,30 @@ fn to_upper_snake_case(s: &str) -> String {
 
 fn to_lower_snake_case(s: &str) -> String {
     let mut buf = String::with_capacity(s.len());
-    let mut prev_is_upper = None;
+    let mut prev = false;
     for c in s.chars() {
-        if c.is_ascii_uppercase() && prev_is_upper == Some(false) {
+        if c.is_ascii_uppercase() && prev {
             buf.push('_')
         }
-        prev_is_upper = Some(c.is_ascii_uppercase());
+        prev = true;
 
         buf.push(c.to_ascii_lowercase());
     }
     buf
 }
+
+fn to_pascal_case(s: &str) -> String {
+    let mut buf = String::with_capacity(s.len());
+    let mut prev_is_underscore = true;
+    for c in s.chars() {
+        if c == '_' {
+            prev_is_underscore = true;
+        } else if prev_is_underscore {
+            buf.push(c.to_ascii_uppercase());
+            prev_is_underscore = false;
+        } else {
+            buf.push(c.to_ascii_lowercase());
+        }
+    }
+    buf
+}