Syntax 2 (#31)

* a little more playing, and syntax feeling better

Author: coffeebe4code

ast/src/lib.rs

@@ -24,6 +24,32 @@ impl For {
     }
 }
 
+#[derive(Debug, Clone, PartialEq)]
+pub struct If {
+    pub expr: Box<Expr>,
+    pub body: Box<Expr>,
+}
+
+impl If {
+    pub fn new(if_expr: Box<Expr>, if_body: Box<Expr>) -> Self {
+        If {
+            expr: if_expr,
+            body: if_body,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct Destructure {
+    pub elements: Vec<Box<Expr>>,
+}
+
+impl Destructure {
+    pub fn new(elements: Vec<Box<Expr>>) -> Self {
+        Destructure { elements }
+    }
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub struct Match {
     pub expr: Box<Expr>,
@@ -300,27 +326,27 @@ pub struct EnumDecl {
     pub visibility: Option<Lexeme>,
     pub mutability: Lexeme,
     pub identifier: Box<Expr>,
-    pub declarators: Vec<Box<Expr>>,
+    pub variants: Vec<Box<Expr>>,
     pub sig: Option<Box<Expr>>,
-    pub variant: Option<Box<Expr>>,
+    pub enum_type: Option<Box<Expr>>,
 }
 
 impl EnumDecl {
     pub fn new(
         visibility: Option<Lexeme>,
         mutability: Lexeme,
         identifier: Box<Expr>,
-        declarators: Vec<Box<Expr>>,
+        variants: Vec<Box<Expr>>,
         sig: Option<Box<Expr>>,
-        variant: Option<Box<Expr>>,
+        enum_type: Option<Box<Expr>>,
     ) -> Self {
         EnumDecl {
             visibility,
             mutability,
             identifier,
-            declarators,
+            variants,
             sig,
-            variant,
+            enum_type,
         }
     }
 }
@@ -330,6 +356,7 @@ pub struct ErrorDecl {
     pub visibility: Option<Lexeme>,
     pub mutability: Lexeme,
     pub identifier: Box<Expr>,
+    pub variants: Vec<Box<Expr>>,
     pub sig: Option<Box<Expr>>,
 }
 
@@ -338,12 +365,14 @@ impl ErrorDecl {
         visibility: Option<Lexeme>,
         mutability: Lexeme,
         identifier: Box<Expr>,
+        variants: Vec<Box<Expr>>,
         sig: Option<Box<Expr>>,
     ) -> Self {
         ErrorDecl {
             visibility,
             mutability,
             identifier,
+            variants,
             sig,
         }
     }
@@ -676,6 +705,8 @@ pub enum Expr {
     ArrayDecl(ArrayDecl),
     Rest(Rest),
     For(For),
+    Destructure(Destructure),
+    If(If),
     While(While),
     Match(Match),
     Arm(Arm),

ebnf.txt

@@ -11,7 +11,7 @@
 <fn> ::= "fn " "(" <args>? ") " <block>
 <struct> ::= "struct " "{ " <declarators>? "}"
 <error> ::= "error " ("| " <ident>)+
-<if> ::= "if " "(" <expr> ")" (<fn> | <block>) ("else if "(" <expr> ")" (<fn> | <block>))* ("else " ( <fn> | <block>))?
+<if> ::= "if " "(" <expr> ")" (<fn> | <block>)
 <for> ::= "for " "(" <expr> ")" (<fn> | <block>)
 <while> ::= "while " "(" <expr> ")" (<fn> | <block>)
 <match> ::= "match " "(" <expr> ")" "{ " <arm>+ "}" 
@@ -41,7 +41,7 @@
 <array_access> ::= "[" <expr> "]"
 <invoke> ::= "." <ident>
 <call> ::= "(" (<or> ("," <or>)*)? ")"
-<struct_body> ::= "{" (<ident> ":" <ident>)* "}"
+<struct_body> ::= "{" (<ident> ":" <or> ("," <ident> ":" <or>))?  "}"
 <terminal> ::= "_" | "true " | "false " | "undefined " | "self " | "never " | <num> | <ident> | <chars> | <array_decl> | <anon_fn> | "(" <expr> ")"
 <anon_fn> ::= "fn " "(" <args>? ") " <block> 
 <ident> ::= ([a-z] | [A-Z]) ([A-Z] | [a-z] | [0-9] | "_")*

linter/src/lib.rs

@@ -58,6 +58,7 @@ impl<'buf, 'ttb, 'sco> LintSource<'buf, 'ttb, 'sco> {
             Expr::Declarator(declarator) => self.check_declarator(&declarator),
             Expr::Match(_match) => self.check_match(&_match),
             Expr::For(_for) => self.check_for(&_for),
+            Expr::If(_if) => self.check_if(&_if),
             Expr::Invoke(invoke) => self.check_invoke(&invoke),
             Expr::PropAccess(prop) => self.check_prop_access(&prop),
             Expr::Arm(arm) => self.check_arm(&arm),
@@ -152,6 +153,19 @@ impl<'buf, 'ttb, 'sco> LintSource<'buf, 'ttb, 'sco> {
         ok_simple_tree!(UndefinedValue, typ)
     }
 
+    pub fn check_if(&mut self, _if: &If) -> ResultTreeType {
+        let res = self.lint_recurse(&_if.expr)?;
+        let body = self.lint_recurse(&_if.body)?;
+        let if_op = IfOp {
+            in_expr: res.0,
+            in_curried: res.1,
+            body: body.0,
+            body_curried: body.1,
+        };
+        let cur = if_op.body_curried.clone();
+        ok_tree!(If, if_op, cur)
+    }
+
     pub fn check_for(&mut self, _for: &For) -> ResultTreeType {
         let res = self.lint_recurse(&_for.expr)?;
         let body = self.lint_recurse(&_for.var_loop)?;

parser/src/lib.rs

@@ -58,7 +58,7 @@ impl<'s> Parser<'s> {
     ) -> ResultExpr {
         let mut variants: Vec<Box<Expr>> = vec![];
         while let Some(_) = self.lexer.collect_if(Token::Bar) {
-            let x = self.ident().xconvert_to_sym_decl()?;
+            let x = self.ident().xconvert_to_decl()?;
             variants.push(x);
         }
         result_expr!(TagDecl, visibility, mutability, identifier, variants, sig)
@@ -71,15 +71,12 @@ impl<'s> Parser<'s> {
         identifier: Box<Expr>,
         sig: Option<Box<Expr>>,
     ) -> ResultExpr {
-        let _ = self
-            .lexer
-            .collect_if(Token::OBrace)
-            .xexpect_token(&self, "expected '{'".to_string())?;
-        let _ = self
-            .lexer
-            .collect_if(Token::CBrace)
-            .xexpect_token(&self, "expected '}'".to_string())?;
-        result_expr!(ErrorDecl, visibility, mutability, identifier, sig)
+        let mut variants: Vec<Box<Expr>> = vec![];
+        while let Some(_) = self.lexer.collect_if(Token::Bar) {
+            let x = self.ident().xconvert_to_decl()?;
+            variants.push(x);
+        }
+        result_expr!(ErrorDecl, visibility, mutability, identifier, variants, sig)
     }
 
     pub fn _enum(
@@ -99,7 +96,7 @@ impl<'s> Parser<'s> {
                 .xexpect_token(&self, "expected ')'".to_string())?;
         }
         while let Some(_) = self.lexer.collect_if(Token::Bar) {
-            let x = self.ident().xconvert_to_sym_decl()?;
+            let x = self.ident().xconvert_to_decl()?;
             variants.push(x);
         }
         result_expr!(EnumDecl, visibility, mutability, identifier, variants, sig, enum_type)
@@ -131,9 +128,9 @@ impl<'s> Parser<'s> {
             .collect_of_if(&[Token::Let, Token::Const, Token::Type, Token::Impl])
             .xexpect_token(&self, "expected mutability".to_string())?;
         let identifier = self
-            .ident()
-            .xexpect_expr(&self, "expected identifier".to_string())
-            .xconvert_to_sym_decl()?;
+            .destructure()
+            .xexpect_expr(&self, "expected identifier, or destructure".to_string())
+            .xconvert_to_decl()?;
         let sig = self.opt_signature()?;
         let _ = self
             .lexer
@@ -266,7 +263,7 @@ impl<'s> Parser<'s> {
         let sig = self
             .opt_signature()
             .xexpect_expr(&self, "expected signature".to_string())?;
-        return result_expr!(Declarator, id.xconvert_to_sym_decl().unwrap(), sig)
+        return result_expr!(Declarator, id.xconvert_to_decl().unwrap(), sig)
             .xconvert_to_result_opt();
     }
     pub fn args(&mut self) -> Result<Option<Vec<Box<Expr>>>> {
@@ -421,8 +418,9 @@ impl<'s> Parser<'s> {
         let mutability = self.lexer.collect_of_if(&[Token::Let, Token::Const]);
         if let Some(muta) = mutability {
             let identifier = self
-                .ident()
-                .xexpect_expr(&self, "expected an identifier".to_string())?;
+                .destructure()
+                .xexpect_expr(&self, "expected identifier, or destructure".to_string())
+                .xconvert_to_decl()?;
             let sig = self.opt_signature()?;
             let _ = self
                 .lexer
@@ -449,8 +447,11 @@ impl<'s> Parser<'s> {
             .lexer
             .collect_if(Token::CParen)
             .xexpect_token(&self, "expected ')'".to_string())?;
+        if let Some(_fn) = self.anon_fn()? {
+            return bubble_expr!(If, x, _fn);
+        }
         let blk = self.block()?;
-        return bubble_expr!(For, x, blk);
+        return bubble_expr!(If, x, blk);
     }
     pub fn _while(&mut self) -> ResultOptExpr {
         let f = self.lexer.collect_if(Token::While);
@@ -492,6 +493,27 @@ impl<'s> Parser<'s> {
         let blk = self.block()?;
         return bubble_expr!(For, x, blk);
     }
+    pub fn destructure(&mut self) -> ResultOptExpr {
+        let brace = self.lexer.collect_if(Token::OBrace);
+        if brace.is_some() {
+            let mut idents: Vec<Box<Expr>> = vec![];
+            loop {
+                match self.ident() {
+                    Some(x) => {
+                        idents.push(Box::new(Expr::SymbolDecl(x.into_symbol())));
+                        let _ = self.lexer.collect_if(Token::Comma);
+                    }
+                    None => break,
+                }
+            }
+            let _ = self
+                .lexer
+                .collect_if(Token::CBrace)
+                .xexpect_token(&self, "expected '}' or more identifiers".to_string())?;
+            return bubble_expr!(Destructure, idents);
+        }
+        return Ok(self.ident());
+    }
     pub fn block(&mut self) -> ResultExpr {
         self.lexer
             .collect_if(Token::OBrace)
@@ -996,12 +1018,12 @@ trait ConvertToResult {
     fn xconvert_to_result(self, parser: &Parser, title: String) -> ResultExpr;
 }
 
-trait ConvertToSymbolDecl {
-    fn xconvert_to_sym_decl(self) -> ResultExpr;
+trait ConvertToDecl {
+    fn xconvert_to_decl(self) -> ResultExpr;
 }
 
-trait ConvertToSymbolDeclResult {
-    fn xconvert_to_sym_decl(self) -> ResultExpr;
+trait ConvertToDeclResult {
+    fn xconvert_to_decl(self) -> ResultExpr;
 }
 
 trait ConvertToResultOpt {
@@ -1077,22 +1099,25 @@ impl ExpectExpr for OptExpr {
     }
 }
 
-impl ConvertToSymbolDeclResult for ResultExpr {
-    fn xconvert_to_sym_decl(self) -> ResultExpr {
+impl ConvertToDeclResult for ResultExpr {
+    fn xconvert_to_decl(self) -> ResultExpr {
         match self {
             Err(x) => Err(x),
             Ok(val) => match *val {
                 Expr::Symbol(x) => {
                     return Ok(Box::new(Expr::SymbolDecl(x)));
                 }
+                Expr::Destructure(_) => {
+                    return Ok(val);
+                }
                 _ => panic!("type lang issue, expected into symbol"),
             },
         }
     }
 }
 
-impl ConvertToSymbolDecl for OptExpr {
-    fn xconvert_to_sym_decl(self) -> ResultExpr {
+impl ConvertToDecl for OptExpr {
+    fn xconvert_to_decl(self) -> ResultExpr {
         match self {
             None => panic!("type lang issue, expected a symbol"),
             Some(val) => match *val {
@@ -1310,14 +1335,11 @@ mod tests {
                         token: Token::Let,
                         span: 2..5,
                     },
-                    expr!(
-                        Symbol,
-                        Lexeme {
-                            slice: String::from("x"),
-                            token: Token::Symbol,
-                            span: 6..7
-                        }
-                    ),
+                    Box::new(Expr::SymbolDecl(Symbol::new(Lexeme {
+                        slice: String::from("x"),
+                        token: Token::Symbol,
+                        span: 6..7
+                    }))),
                     None,
                     expr!(
                         Number,