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/math.rs

@@ -0,0 +1,70 @@
+//! Functions related to mathematics.
+
+use anyhow::Result;
+use derive_docs::stdlib;
+use schemars::JsonSchema;
+
+use crate::{errors::KclError, executor::MemoryItem, std::Args};
+
+/// Computes the cosine of a number (in radians).
+pub fn cos(args: &mut Args) -> Result<MemoryItem, KclError> {
+    let num = args.get_number()?;
+    let result = inner_cos(num)?;
+
+    args.make_user_val_from_f64(result)
+}
+
+/// Computes the sine of a number (in radians).
+#[stdlib {
+    name = "cos",
+}]
+fn inner_cos(num: f64) -> Result<f64, KclError> {
+    Ok(num.cos())
+}
+
+/// Computes the sine of a number (in radians).
+pub fn sin(args: &mut Args) -> Result<MemoryItem, KclError> {
+    let num = args.get_number()?;
+    let result = inner_sin(num)?;
+
+    args.make_user_val_from_f64(result)
+}
+
+/// Computes the sine of a number (in radians).
+#[stdlib {
+    name = "sin",
+}]
+fn inner_sin(num: f64) -> Result<f64, KclError> {
+    Ok(num.sin())
+}
+
+/// Computes the tangent of a number (in radians).
+pub fn tan(args: &mut Args) -> Result<MemoryItem, KclError> {
+    let num = args.get_number()?;
+    let result = inner_tan(num)?;
+
+    args.make_user_val_from_f64(result)
+}
+
+/// Computes the tangent of a number (in radians).
+#[stdlib {
+    name = "tan",
+}]
+fn inner_tan(num: f64) -> Result<f64, KclError> {
+    Ok(num.tan())
+}
+
+/// Return the value of `pi`.
+pub fn pi(args: &mut Args) -> Result<MemoryItem, KclError> {
+    let result = inner_pi()?;
+
+    args.make_user_val_from_f64(result)
+}
+
+/// Return the value of `pi`.
+#[stdlib {
+    name = "pi",
+}]
+fn inner_pi() -> Result<f64, KclError> {
+    Ok(std::f64::consts::PI)
+}