add parser implementation

Author: UnsignedByte

crates/ast/src/parser.rs

@@ -239,6 +239,13 @@ impl FilamentParser {
             .map_err(|_| input.error("Expected valid bitwidth"))
     }
 
+    fn float(input: Node) -> ParseResult<f64> {
+        input
+            .as_str()
+            .parse::<f64>()
+            .map_err(|_| input.error("Expected valid float"))
+    }
+
     // ================ Intervals =====================
     fn time(input: Node) -> ParseResult<Loc<ast::Time>> {
         let sp = Self::get_span(&input);
@@ -833,12 +840,13 @@ impl FilamentParser {
         Ok(())
     }
 
-    fn attributes<Bool, Num>(
+    fn attributes<Bool, Num, Float>(
         input: Node,
-    ) -> ParseResult<utils::Attributes<Bool, Num>>
+    ) -> ParseResult<utils::Attributes<Bool, Num, Float>>
     where
         Bool: FromStr + Hash + Eq + Copy,
         Num: FromStr + Hash + Eq + Copy,
+        Float: FromStr + Hash + Eq + Copy,
     {
         let mut attrs = utils::Attributes::default();
         for attr in input.into_children() {
@@ -853,6 +861,9 @@ impl FilamentParser {
                 [identifier(name), bitwidth(val)] => Num::from_str(name.as_ref()).map(
                     |attr| attrs.set(attr, val, name.pos())).map_err(
                         |_| attr.error(format!("Found unknown numeric attribute \"{name}\""))),
+                [identifier(name), float(val)] => Float::from_str(name.as_ref()).map(
+                    |attr| attrs.set(attr, val, name.pos())).map_err(
+                        |_| attr.error(format!("Found unknown float attribute \"{name}\""))),
             )?;
         }
 

crates/ast/src/syntax.pest

@@ -9,6 +9,9 @@ identifier = @{ ("_" | ASCII_ALPHA)+ ~ ("_" | ASCII_ALPHA | ASCII_DIGIT)* }
 // Positive numbers
 bitwidth = @{ ASCII_DIGIT+ }
 
+// Float
+float = @{ ASCII_DIGIT+ ~ "." ~ ASCII_DIGIT+ }
+
 char = { !"\"" ~ ANY }
 string_lit = ${ "\"" ~ char* ~ "\"" }
 import = _{
@@ -74,6 +77,7 @@ not = { "not" }
 attr_bind = {
   not ~ "(" ~ identifier ~ ")"
   | identifier ~ "=" ~ bitwidth
+  | identifier ~ "=" ~ float
   | identifier
 }