Changes in api and upwards

- Removed out-of-stack error reporting
- Revised module system to match previous Orchid system
- Errors are now in a Vec everywhere
- Implemented atoms and lexer
- Started implementation of line parser
- Tree is now ephemeral to avoid copying Atoms held inside
- Moved numbers into std and the shared parser into base
- Started implementation of Commands

orchid-std/src/number/num_lexer.rs

@@ -0,0 +1,44 @@
+use std::ops::RangeInclusive;
+
+use orchid_base::location::Pos;
+use orchid_base::number::{parse_num, NumError, NumErrorKind, Numeric};
+use orchid_extension::atom::AtomicFeatures;
+use orchid_extension::error::{ProjectError, ProjectResult};
+use orchid_extension::lexer::{LexContext, Lexer};
+use orchid_extension::tree::{GenTok, GenTokTree};
+use ordered_float::NotNan;
+
+use super::num_atom::{Float, Int};
+
+struct NumProjError(u32, NumError);
+impl ProjectError for NumProjError {
+  const DESCRIPTION: &'static str = "Failed to parse number";
+  fn message(&self) -> String {
+    match self.1.kind {
+      NumErrorKind::InvalidDigit => "This character is not meaningful in this base",
+      NumErrorKind::NaN => "Number somehow evaluated to NaN",
+      NumErrorKind::Overflow => "Number literal overflowed its enclosing type",
+    }
+    .to_string()
+  }
+  fn one_position(&self) -> Pos {
+    Pos::Range(self.0 + self.1.range.start as u32..self.0 + self.1.range.end as u32)
+  }
+}
+
+#[derive(Default)]
+pub struct NumLexer;
+impl Lexer for NumLexer {
+  const CHAR_FILTER: &'static [RangeInclusive<char>] = &['0'..='9'];
+  fn lex<'a>(all: &'a str, ctx: &'a LexContext<'a>) -> ProjectResult<(&'a str, GenTokTree)> {
+    let ends_at = all.find(|c: char| !c.is_ascii_hexdigit() && !"xX._pP".contains(c));
+    let (chars, tail) = all.split_at(ends_at.unwrap_or(all.len()));
+    let fac = match parse_num(chars) {
+      Ok(Numeric::Float(f)) => Float(f).factory(),
+      Ok(Numeric::Uint(uint)) => Int(uint.try_into().unwrap()).factory(),
+      Ok(Numeric::Decimal(dec)) => Float(NotNan::new(dec.try_into().unwrap()).unwrap()).factory(),
+      Err(e) => return Err(NumProjError(ctx.pos(all), e).pack()),
+    };
+    Ok((tail, GenTok::Atom(fac).at(ctx.pos(all)..ctx.pos(tail))))
+  }
+}