Add literals

src/grammar.pest

@@ -1 +1,19 @@
 file = { "hello world" }
+
+literal = { string | number | boolean }
+
+string = { "\"" ~ (!"\"" ~ ANY)* ~ "\"" }
+
+number = _{ byte | float | integer }
+
+integer = @{ "-"? ~ ASCII_DIGIT+ }
+
+float = @{
+    "-"? ~ (ASCII_DIGIT+ ~ "." ~ ASCII_DIGIT* | ASCII_DIGIT* ~ "." ~ ASCII_DIGIT+)
+}
+
+byte = @{ "0x" ~ ASCII_HEX_DIGIT{1, 2} | "0b" ~ ASCII_BIN_DIGIT{0, 8} }
+
+boolean = @{ "true" | "false" }
+
+WHITESPACE = _{ " " | "\t" | "\r" | "\n" }

src/lib.rs

@@ -9,12 +9,97 @@ pub fn parse<'a>(src: &'a str) -> Result<Pairs<'a, Rule>, pest::error::Error<Rul
     SnekParser::parse(Rule::file, src)
 }
 
+pub fn parse_rule<'a>(
+    rule: Rule,
+    src: &'a str,
+) -> Result<Pairs<'a, Rule>, pest::error::Error<Rule>> {
+    SnekParser::parse(rule, src)
+}
+
 #[cfg(test)]
 mod test {
-    use crate::parse;
+
+    use pest::iterators::Pair;
+
+    use crate::{parse, parse_rule, Rule};
+
+    fn parse_token<'a>(rule: Rule, src: &'a str) -> Pair<'a, Rule> {
+        let mut pairs = parse_rule(rule, src).unwrap();
+        pairs.next().unwrap()
+    }
+
+    fn parse_inner_token<'a>(rule: Rule, src: &'a str) -> Pair<'a, Rule> {
+        parse_token(rule, src).into_inner().next().unwrap()
+    }
 
     #[test]
     fn it_parses() {
         parse("hello world").unwrap();
     }
+
+    #[test]
+    fn it_parses_numbers() {
+        assert_eq!(
+            parse_inner_token(Rule::literal, "0").as_rule(),
+            Rule::integer
+        );
+        assert_eq!(
+            parse_inner_token(Rule::literal, "100").as_rule(),
+            Rule::integer
+        );
+    }
+
+    #[test]
+    fn it_parses_floats() {
+        assert_eq!(
+            parse_inner_token(Rule::literal, "0.").as_rule(),
+            Rule::float
+        );
+        assert_eq!(
+            parse_inner_token(Rule::literal, ".5").as_rule(),
+            Rule::float
+        );
+        assert_eq!(
+            parse_inner_token(Rule::literal, "11.15").as_rule(),
+            Rule::float
+        );
+    }
+
+    #[test]
+    fn it_parses_bytes() {
+        assert_eq!(
+            parse_inner_token(Rule::literal, "0xFF").as_rule(),
+            Rule::byte
+        );
+        assert_eq!(
+            parse_inner_token(Rule::literal, "0b0010").as_rule(),
+            Rule::byte
+        );
+    }
+
+    #[test]
+    fn it_parses_strings() {
+        assert_eq!(
+            parse_inner_token(Rule::literal, r#""Hello world""#).as_rule(),
+            Rule::string
+        );
+        assert_eq!(
+            parse_inner_token(Rule::literal, r#""""#).as_rule(),
+            Rule::string
+        );
+    }
+
+    #[test]
+    fn it_parses_booleans() {
+        assert_eq!(
+            parse_inner_token(Rule::literal, "true").as_rule(),
+            Rule::boolean
+        );
+        assert_eq!(parse_inner_token(Rule::literal, "true").as_str(), "true");
+        assert_eq!(
+            parse_inner_token(Rule::literal, "false").as_rule(),
+            Rule::boolean
+        );
+        assert_eq!(parse_inner_token(Rule::literal, "false").as_str(), "false");
+    }
 }