src/parser.rs

@@ -1,12 +1,17 @@
 use nom::{
     branch::alt,
-    bytes::complete::{escaped, is_not, tag, take_until},
-    character::complete::{alpha1, alphanumeric1, char, multispace0, one_of, space0},
-    combinator::{cut, map, recognize, value},
-    error::ParseError,
+    bytes::complete::{escaped, is_not},
+    bytes::complete::{tag, take_until},
+    character::complete::char,
+    character::complete::multispace0,
+    character::complete::{alpha1, alphanumeric1, digit1, one_of, space0},
+    combinator::value,
+    combinator::{cut, map, map_res, recognize},
+    error::{context, convert_error, ContextError, ErrorKind, ParseError, VerboseError},
     multi::{fold_many0, many0, separated_list0},
     number::complete::double,
-    sequence::{delimited, pair, preceded, terminated, tuple},
+    sequence::pair,
+    sequence::{delimited, preceded, terminated, tuple},
     IResult, Parser,
 };
 
@@ -23,11 +28,17 @@ fn pinline_comment<'a, E>(i: &'a str) -> IResult<&'a str, (), E>
 where
     E: ParseError<&'a str>,
 {
-    value((), tuple((tag("/*"), take_until("*/"), tag("*/"))))(i)
+    value(
+        (), // Output is thrown away.
+        tuple((tag("/*"), take_until("*/"), tag("*/"))),
+    )(i)
 }
 
 fn peol_comment<'a, E: ParseError<&'a str>>(i: &'a str) -> IResult<&'a str, (), E> {
-    value((), pair(char('/'), is_not("\n\r")))(i)
+    value(
+        (), // Output is thrown away.
+        pair(char('/'), is_not("\n\r")),
+    )(i)
 }
 
 fn braces<'a, P, O, E>(a: P) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
@@ -50,17 +61,11 @@ where
     )
 }
 
-fn identifier(i: &str) -> IResult<&str, &str> {
-    println!("identifier: {}", i);
+fn identifier(input: &str) -> IResult<&str, &str> {
     recognize(pair(
         alt((alpha1, tag("_"))),
         many0(alt((alphanumeric1, tag("_")))),
-    ))(i)
-}
-
-fn variable(i: &str) -> IResult<&str, Expr> {
-    println!("variable: {}", i);
-    map(identifier, |a| Expr::Var(a.to_string()))(i)
+    ))(input)
 }
 
 fn parse_str<'a>(i: &'a str) -> IResult<&'a str, &'a str> {
@@ -68,7 +73,6 @@ fn parse_str<'a>(i: &'a str) -> IResult<&'a str, &'a str> {
 }
 
 fn string<'a>(i: &'a str) -> IResult<&'a str, Expr> {
-    println!("string: {}", i);
     map(
         preceded(char('\"'), cut(terminated(parse_str, char('\"')))),
         |s| Expr::LStr(String::from(s)),
@@ -83,22 +87,18 @@ fn boolean<'a>(i: &'a str) -> IResult<&'a str, Expr> {
     ))(i)
 }
 
-fn call<'a>(i: &'a str) -> IResult<&'a str, Expr> {
+fn call<'a>(i: &'a str) -> IResult<&'a str, (Identifier, Vec<Expr>)> {
     println!("call: {}", i);
     map(
         tuple((
             identifier,
-            sc,
-            alt((
-                value(vec![], tuple((char('('), sc, char(')')))),
-                delimited(
-                    char('('),
-                    separated_list0(tuple((sc, tag(","), sc)), expr),
-                    char(')'),
-                ),
-            )),
+            delimited(
+                char('('),
+                separated_list0(tuple((sc, tag(","), sc)), expr),
+                char(')'),
+            ),
         )),
-        |(i, _, v)| Expr::Call(i.to_string(), v),
+        |(i, v)| (i.to_string(), v),
     )(i)
 }
 
@@ -112,7 +112,7 @@ fn literal(i: &str) -> IResult<&str, Expr> {
 }
 
 fn factor_bin(i: &str) -> IResult<&str, Expr> {
-    alt((delimited(space0, term, space0), expr))(i)
+    alt((delimited(space0, literal, space0), expr))(i)
 }
 
 fn bin_less_greater(i: &str) -> IResult<&str, Expr> {
@@ -134,13 +134,13 @@ fn bin_equal_not(i: &str) -> IResult<&str, Expr> {
     let (i, init) = bin_less_greater(i)?;
 
     fold_many0(
-        pair(alt((tag("=="), tag("!="))), bin_less_greater),
+        pair(alt((char('<'), char('>'))), bin_less_greater),
         move || init.clone(),
-        |acc, (op, val)| {
-            if op == "==" {
-                Expr::Binary(BinOp::Equals, Box::new(acc), Box::new(val))
+        |acc, (op, val): (char, Expr)| {
+            if op == '<' {
+                Expr::Binary(BinOp::LessThan, Box::new(acc), Box::new(val))
             } else {
-                Expr::Binary(BinOp::NotEquals, Box::new(acc), Box::new(val))
+                Expr::Binary(BinOp::GreaterThan, Box::new(acc), Box::new(val))
             }
         },
     )(i)
@@ -177,19 +177,25 @@ fn binary<'a>(i: &'a str) -> IResult<&'a str, Expr> {
     )(i)
 }
 fn receive<'a>(i: &'a str) -> IResult<&'a str, Expr> {
-    println!("receive: {}", i);
     map(pair(tag("<-"), expr), |(_, expr)| {
         Expr::Receive(Box::new(expr))
     })(i)
 }
 
 pub fn expr<'a>(i: &'a str) -> IResult<&'a str, Expr> {
-    alt((receive, binary))(i)
-}
-
-fn term<'a>(i: &'a str) -> IResult<&'a str, Expr> {
     println!("expr: {}", i);
-    delimited(sc, alt((literal, call, variable, parens(expr))), sc)(i)
+    delimited(
+        sc,
+        alt((
+            parens(expr),
+            map(call, |(i, v)| Expr::Call(i, v)),
+            receive,
+            binary,
+            literal,
+            map(identifier, |i| Expr::Var(i.to_string())),
+        )),
+        sc,
+    )(i)
 }
 
 #[cfg(test)]
@@ -208,7 +214,7 @@ mod tests {
     #[test]
     fn can_parse_binary_op() {
         let a = "3 +3 +  6";
-        let (_rest, res) = expr(a).unwrap();
+        let (_rest, res) = binary(a).unwrap();
 
         assert_eq!(
             res,
@@ -227,7 +233,7 @@ mod tests {
     #[test]
     fn can_parse_binary_op_with_str() {
         let a = r#"3 +3 +  6 + "hey""#;
-        let (_rest, res) = expr(a).unwrap();
+        let (_rest, res) = binary(a).unwrap();
 
         assert_eq!(
             res,
@@ -247,15 +253,6 @@ mod tests {
         );
     }
 
-    #[test]
-    fn can_parse_var() {
-        let a = "hello";
-        let (rest, res) = expr(a).unwrap();
-
-        assert_eq!(res, Expr::Var("hello".to_string()));
-        assert_eq!(rest, "");
-    }
-
     #[test]
     fn can_parse_empty_call() {
         let a = "hello()";
@@ -265,18 +262,6 @@ mod tests {
         assert_eq!(rest, "");
     }
 
-    #[test]
-    fn can_parse_call_with_var() {
-        let a = "hello(hey)";
-        let (rest, res) = expr(a).unwrap();
-
-        assert_eq!(
-            res,
-            Expr::Call("hello".to_string(), vec![Expr::Var("hey".to_string())])
-        );
-        assert_eq!(rest, "");
-    }
-
     #[test]
     fn can_parse_call() {
         let a = "hello(1.0, 45 , yeah)";