Reorganize library

1 files changed, 114 insertions, 0 deletions

diff --git a/src/library/utility/math.rs b/src/library/utility/math.rs
new file mode 100644
index 00000000..795f39fd
--- /dev/null
+++ b/src/library/utility/math.rs
@@ -0,0 +1,114 @@
+use std::cmp::Ordering;
+
+use crate::library::prelude::*;
+
+/// The absolute value of a numeric value.
+pub fn abs(_: &mut Context, args: &mut Args) -> TypResult<Value> {
+    let Spanned { v, span } = args.expect("numeric value")?;
+    Ok(match v {
+        Value::Int(v) => Value::Int(v.abs()),
+        Value::Float(v) => Value::Float(v.abs()),
+        Value::Length(v) => Value::Length(v.abs()),
+        Value::Angle(v) => Value::Angle(v.abs()),
+        Value::Relative(v) => Value::Relative(v.abs()),
+        Value::Fractional(v) => Value::Fractional(v.abs()),
+        Value::Linear(_) => bail!(span, "cannot take absolute value of a linear"),
+        v => bail!(span, "expected numeric value, found {}", v.type_name()),
+    })
+}
+
+/// The minimum of a sequence of values.
+pub fn min(_: &mut Context, args: &mut Args) -> TypResult<Value> {
+    minmax(args, Ordering::Less)
+}
+
+/// The maximum of a sequence of values.
+pub fn max(_: &mut Context, args: &mut Args) -> TypResult<Value> {
+    minmax(args, Ordering::Greater)
+}
+
+/// Find the minimum or maximum of a sequence of values.
+fn minmax(args: &mut Args, goal: Ordering) -> TypResult<Value> {
+    let mut extremum = args.expect::<Value>("value")?;
+    for Spanned { v, span } in args.all::<Spanned<Value>>()? {
+        match v.partial_cmp(&extremum) {
+            Some(ordering) => {
+                if ordering == goal {
+                    extremum = v;
+                }
+            }
+            None => bail!(
+                span,
+                "cannot compare {} with {}",
+                extremum.type_name(),
+                v.type_name(),
+            ),
+        }
+    }
+    Ok(extremum)
+}
+
+/// Whether an integer is even.
+pub fn even(_: &mut Context, args: &mut Args) -> TypResult<Value> {
+    Ok(Value::Bool(args.expect::<i64>("integer")? % 2 == 0))
+}
+
+/// Whether an integer is odd.
+pub fn odd(_: &mut Context, args: &mut Args) -> TypResult<Value> {
+    Ok(Value::Bool(args.expect::<i64>("integer")? % 2 != 0))
+}
+
+/// The modulo of two numbers.
+pub fn modulo(_: &mut Context, args: &mut Args) -> TypResult<Value> {
+    let Spanned { v: v1, span: span1 } = args.expect("integer or float")?;
+    let Spanned { v: v2, span: span2 } = args.expect("integer or float")?;
+
+    let (a, b) = match (v1, v2) {
+        (Value::Int(a), Value::Int(b)) => match a.checked_rem(b) {
+            Some(res) => return Ok(Value::Int(res)),
+            None => bail!(span2, "divisor must not be zero"),
+        },
+        (Value::Int(a), Value::Float(b)) => (a as f64, b),
+        (Value::Float(a), Value::Int(b)) => (a, b as f64),
+        (Value::Float(a), Value::Float(b)) => (a, b),
+        (Value::Int(_), b) | (Value::Float(_), b) => bail!(
+            span2,
+            format!("expected integer or float, found {}", b.type_name())
+        ),
+        (a, _) => bail!(
+            span1,
+            format!("expected integer or float, found {}", a.type_name())
+        ),
+    };
+
+    if b == 0.0 {
+        bail!(span2, "divisor must not be zero");
+    }
+
+    Ok(Value::Float(a % b))
+}
+
+/// Create a sequence of numbers.
+pub fn range(_: &mut Context, args: &mut Args) -> TypResult<Value> {
+    let first = args.expect::<i64>("end")?;
+    let (start, end) = match args.eat::<i64>()? {
+        Some(second) => (first, second),
+        None => (0, first),
+    };
+
+    let step: i64 = match args.named("step")? {
+        Some(Spanned { v: 0, span }) => bail!(span, "step must not be zero"),
+        Some(Spanned { v, .. }) => v,
+        None => 1,
+    };
+
+    let mut x = start;
+    let mut seq = vec![];
+
+    while x.cmp(&end) == 0.cmp(&step) {
+        seq.push(Value::Int(x));
+        x += step;
+    }
+
+    Ok(Value::Array(Array::from_vec(seq)))
+}