Renames, eof and comment fixes

rust/src/parser.rs

@@ -1,42 +1,44 @@
 #[derive(Debug,PartialEq)]
-pub enum Statement<'a> {
-    Assignment(&'a str, Expression<'a>),
+pub enum Stmt<'a> {
+    Assignment(&'a str, Expr<'a>),
     Funcall(Funcall<'a>),
 }
 
 #[derive(Debug,PartialEq)]
-pub enum Expression<'a> {
+pub enum Expr<'a> {
     Id(&'a str),
     Num(f64),
     Funcall(Funcall<'a>),
-    Plus(Box<Expression<'a>>, Box<Expression<'a>>),
-    Minus(Box<Expression<'a>>, Box<Expression<'a>>),
-    Mult(Box<Expression<'a>>, Box<Expression<'a>>),
+    Plus(Box<Expr<'a>>, Box<Expr<'a>>),
+    Minus(Box<Expr<'a>>, Box<Expr<'a>>),
+    Mult(Box<Expr<'a>>, Box<Expr<'a>>),
+    Div(Box<Expr<'a>>, Box<Expr<'a>>),
 }
 
 #[derive(Debug,PartialEq)]
 pub struct Funcall<'a> {
     id: &'a str,
-    args: Vec<Expression<'a>>,
+    args: Vec<Expr<'a>>,
 }
 
 peg::parser! {
     grammar deelang_parser() for str {
-	pub rule program() -> Vec<Statement<'input>>
-	    = __* s:statement()* eof() { s }
-	pub rule statement() -> Statement<'input>
-	    = i:id() "<-" _ e:expr() __* { Statement::Assignment(i, e) } /
-	    f:funcall() __* { Statement::Funcall(f)}
-	rule expr() -> Expression<'input> = precedence!{
-	    e1:(@) "+" _ e2:@ { Expression::Plus(Box::new(e1), Box::new(e2)) }
-	    e1:(@) "-" _ e2:@ { Expression::Minus(Box::new(e1), Box::new(e2)) }
+	pub rule program() -> Vec<Stmt<'input>>
+	    = __* s:stmt()* { s }
+	pub rule stmt() -> Stmt<'input>
+	    = i:id() "<-" _ e:expr() stop() { Stmt::Assignment(i, e) } /
+	    f:funcall() stop() { Stmt::Funcall(f) }
+	rule expr() -> Expr<'input> = precedence!{
+	    e1:(@) "+" _ e2:@ { Expr::Plus(Box::new(e1), Box::new(e2)) }
+	    e1:(@) "-" _ e2:@ { Expr::Minus(Box::new(e1), Box::new(e2)) }
 	    --
-            e1:(@) "*" _ e2:@ { Expression::Mult(Box::new(e1), Box::new(e2)) }
+            e1:(@) "*" _ e2:@ { Expr::Mult(Box::new(e1), Box::new(e2)) }
+	    e1:(@) "/" _ e2:@ { Expr::Div(Box::new(e1), Box::new(e2)) }
 	    --
             "(" _ e:expr() ")" _ { e } 
-	    f:funcall() _ { Expression::Funcall(f) }
-	    i:id() _ { Expression::Id(i) }
-	    n:num() _ { Expression::Num(n) }
+	    f:funcall() _ { Expr::Funcall(f) }
+	    i:id() _ { Expr::Id(i) }
+	    n:num() _ { Expr::Num(n) }
 	}
 	
 	rule id() -> &'input str
@@ -50,10 +52,12 @@ peg::parser! {
 	    = ['A'..='Z'] / ['a'..='z']
 	rule digit()
 	    = ['0'..='9']
+	rule stop()
+	    = __+ / eof()
 	rule _ // Non-meaningful whitespace
 	    = ['\t'|' ']*
-	rule __ // Blank lines and lines containing only comments
-	    = comment() &eof() / comment() newline() / newline()
+	rule __ // End Of Statement (comment, newline, eof, TODO semicolon)
+	    = comment()? newline() / comment() &eof()
 	rule comment()
 	    = "#" (!newline() [_])* &(newline() / eof())
 	rule newline()
@@ -70,18 +74,20 @@ mod test {
     
     #[test]
     fn test_comments() {
-	let expected = vec![];
-	let prgm = "## This is a comment";
+	let prgm = "## This is a comment
+apple <- 1 ## This is too
+## This comment ends the file";
+	let expected = vec![Stmt::Assignment("apple", Expr::Num(1.0))];
 	assert_eq!(deelang_parser::program(prgm).unwrap(), expected);
     }
 
     #[test]
     fn test_funcall() {
 	let expected = vec![
-	    Statement::Funcall(Funcall{id: "pear", args: vec![]}),
- 	    Statement::Funcall(Funcall {
+	    Stmt::Funcall(Funcall{id: "pear", args: vec![]}),
+ 	    Stmt::Funcall(Funcall {
  		id: "pear",
- 		args: vec![Expression::Id("x"), Expression::Id("y")],
+ 		args: vec![Expr::Id("x"), Expr::Id("y")],
  	    })
 	];
 	let prgm = r"pear()
@@ -94,14 +100,14 @@ pear(x, y)";
 	let prgm = r"apple <- 1
 apple <- pear(x, y)";
 	let expected = vec![
-	    Statement::Assignment("apple",
-				  Expression::Num(1.0)),
-	    Statement::Assignment("apple",
-				  Expression::Funcall(Funcall {
+	    Stmt::Assignment("apple",
+				  Expr::Num(1.0)),
+	    Stmt::Assignment("apple",
+				  Expr::Funcall(Funcall {
 				      id: "pear",
 				      args: vec![
-					  Expression::Id("x"),
-					  Expression::Id("y"),
+					  Expr::Id("x"),
+					  Expr::Id("y"),
 				      ]})),
 	];
 	assert_eq!(deelang_parser::program(prgm).unwrap(), expected);
@@ -113,23 +119,23 @@ apple <- pear(x, y)";
 one <- 3 - 2
 four <- (3 - 1) * 2";
 	let expected = vec![
-	    Statement::Assignment("three",
-				  Expression::Plus(
-				      Box::new(Expression::Num(1.0)),
-				      Box::new(Expression::Num(2.0))
+	    Stmt::Assignment("three",
+				  Expr::Plus(
+				      Box::new(Expr::Num(1.0)),
+				      Box::new(Expr::Num(2.0))
 				  )),
-	    Statement::Assignment("one",
-				  Expression::Minus(
-				      Box::new(Expression::Num(3.0)),
-				      Box::new(Expression::Num(2.0))
+	    Stmt::Assignment("one",
+				  Expr::Minus(
+				      Box::new(Expr::Num(3.0)),
+				      Box::new(Expr::Num(2.0))
 				  )),
-	    Statement::Assignment("four",
-				  Expression::Mult(
-				      Box::new(Expression::Minus(
-					  Box::new(Expression::Num(3.0)),
-					  Box::new(Expression::Num(1.0)),
+	    Stmt::Assignment("four",
+				  Expr::Mult(
+				      Box::new(Expr::Minus(
+					  Box::new(Expr::Num(3.0)),
+					  Box::new(Expr::Num(1.0)),
 				      )),
-				      Box::new(Expression::Num(2.0)),
+				      Box::new(Expr::Num(2.0)),
 				  ))
 	];
 	assert_eq!(deelang_parser::program(prgm).unwrap(), expected);