add sin cos tan to stdlib and make sure you cant redeclare a stdlib fn (#497)

more tests

Signed-off-by: Jess Frazelle <github@jessfraz.com>

src/wasm-lib/kcl/src/std/mod.rs

@@ -1,6 +1,7 @@
 //! Functions implemented for language execution.
 
 pub mod extrude;
+pub mod math;
 pub mod segment;
 pub mod sketch;
 pub mod utils;
@@ -61,6 +62,10 @@ impl StdLib {
             Box::new(crate::std::sketch::Close),
             Box::new(crate::std::sketch::Arc),
             Box::new(crate::std::sketch::BezierCurve),
+            Box::new(crate::std::math::Cos),
+            Box::new(crate::std::math::Sin),
+            Box::new(crate::std::math::Tan),
+            Box::new(crate::std::math::Pi),
         ];
 
         let mut fns = HashMap::new();
@@ -122,6 +127,21 @@ impl<'a> Args<'a> {
         )?))
     }
 
+    fn get_number(&self) -> Result<f64, KclError> {
+        let first_value = self
+            .args
+            .first()
+            .ok_or_else(|| {
+                KclError::Type(KclErrorDetails {
+                    message: format!("Expected a number as the first argument, found `{:?}`", self.args),
+                    source_ranges: vec![self.source_range],
+                })
+            })?
+            .get_json_value()?;
+
+        parse_json_number_as_f64(&first_value, self.source_range)
+    }
+
     fn get_number_array(&self) -> Result<Vec<f64>, KclError> {
         let mut numbers: Vec<f64> = Vec::new();
         for arg in &self.args {