work

src/parser/v3/nodes/lit.rs

@@ -0,0 +1,114 @@
+use super::{
+    CharCursor, MaybeParsable, ParserError, ParserErrors, Symbol, Token, TokenCursor,
+};
+use std::fmt::Debug;
+
+#[derive(Clone, PartialEq, Eq)]
+pub enum Literal {
+    String(String),
+    Char(char),
+    Number(Number),
+    Unit,
+}
+
+#[derive(Clone, PartialEq, Eq)]
+pub struct Number {
+    pub whole: String,
+    pub decimal: Option<String>,
+    pub ty: Option<String>,
+}
+
+impl MaybeParsable for Literal {
+    fn maybe_parse(
+        cursor: &mut TokenCursor,
+        _: &mut ParserErrors,
+    ) -> Result<Option<Self>, ParserError> {
+        let inst = cursor.expect_peek()?;
+        let mut res = match &inst.token {
+            Token::Symbol(Symbol::SingleQuote) => {
+                let chars = cursor.chars();
+                let c = chars.expect_next()?;
+                chars.expect('\'')?;
+                Self::Char(c)
+            }
+            Token::Symbol(Symbol::DoubleQuote) => Self::String(string_from(cursor.chars())?),
+            Token::Ident(text) => {
+                let first = text.chars().next().unwrap();
+                if first.is_ascii_digit() {
+                    Self::Number(Number {
+                        whole: text.to_string(),
+                        decimal: None,
+                        ty: None,
+                    })
+                } else {
+                    return Ok(None);
+                }
+            }
+            _ => return Ok(None),
+        };
+        cursor.next();
+        if let (Some(next), Self::Number(num)) = (cursor.peek(), &mut res) {
+            if next.token.is_symbol(Symbol::Dot) {
+                cursor.next();
+                if let Some(next) = cursor.peek() {
+                    if let Token::Ident(i) = &next.token {
+                        if i.chars().next().unwrap().is_ascii_digit() {
+                            num.decimal = Some(i.to_string());
+                            cursor.next();
+                        }
+                    }
+                }
+            }
+        }
+        Ok(Some(res))
+    }
+}
+pub fn string_from(cursor: &mut CharCursor) -> Result<String, ParserError> {
+    let mut str = String::new();
+    loop {
+        let c = cursor.expect_next()?;
+        if c == '"' {
+            return Ok(str);
+        }
+        str.push(match c {
+            '\\' => {
+                let next = cursor.expect_next()?;
+                match next {
+                    '"' => '"',
+                    '\'' => '\'',
+                    't' => '\t',
+                    'n' => '\n',
+                    '0' => '\0',
+                    _ => {
+                        todo!();
+                    }
+                }
+            }
+            _ => c,
+        })
+    }
+}
+
+impl Debug for Literal {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::String(str) => str.fmt(f),
+            Self::Char(c) => c.fmt(f),
+            Self::Number(n) => n.fmt(f),
+            Self::Unit => f.write_str("()"),
+        }
+    }
+}
+
+impl Debug for Number {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.whole)?;
+        if let Some(d) = &self.decimal {
+            write!(f, ".{}", d)?;
+        }
+        if let Some(ty) = &self.ty {
+            write!(f, "T{}", ty)?;
+        }
+        Ok(())
+    }
+}