add: string_parser and char_satisfy parser.

src/text.rs

@@ -1,23 +1,16 @@
-use crate::parser::{satisfy, take, FailedParserResult, Parser};
+mod string_parsers;
+
+use crate::parser::{satisfy, Parser};
+use crate::text::string_parsers::StringParser;
 
 pub fn char_parser<'a, TContext>(c: char) -> impl Parser<'a, char, char, TContext> {
     satisfy(move |x| *x == c)
 }
 
-pub fn string_parser<'a, TContext>(str: &'static str) -> impl Parser<'a, char, String, TContext> {
-    take::<char, TContext>(str.chars().count()).next(move |result| {
-        result.and_then(|(input, chars)| {
-            let chars: String = chars.iter().collect();
-            if chars == str {
-                Ok((input, chars))
-            } else {
-                Err((
-                    input,
-                    FailedParserResult::new(format!("Failed to parse '{}'.", str)),
-                ))
-            }
-        })
-    })
+pub fn string_parser<'a, TContext>(
+    str: &'static str,
+) -> impl Parser<'a, char, &'a [char], TContext> {
+    StringParser { str }
 }
 
 pub fn one_of<'a, TContext>(str: &'static str) -> impl Parser<'a, char, char, TContext> {
@@ -25,6 +18,13 @@ pub fn one_of<'a, TContext>(str: &'static str) -> impl Parser<'a, char, char, TC
     satisfy(move |c: &char| str.contains(c))
 }
 
+pub fn char_satisfy<'a, TContext, F>(condition: F) -> impl Parser<'a, char, char, TContext>
+where
+    F: Fn(&char) -> bool,
+{
+    satisfy(move |x: &char| condition(x))
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -52,7 +52,11 @@ mod test {
         parser_test_helper(
             ParserContext::new_with_str("Hello, world!", ()),
             &"Hello".to_owned(),
-            |context, input| string_parser("Hello").parse(context, input),
+            |context, input| {
+                string_parser("Hello")
+                    .map(|x| x.iter().collect())
+                    .parse(context, input)
+            },
         );
 
         fn test_parser(
@@ -62,7 +66,10 @@ mod test {
             let (input, first) = string_parser("hello, ").parse(context.clone(), input)?;
             let (input, second) = string_parser("world!").parse(context.clone(), input)?;
 
-            Ok((input, first + second.as_str()))
+            Ok((
+                input,
+                first.iter().collect::<String>() + second.iter().collect::<String>().as_str(),
+            ))
         }
 
         parser_test_helper(
@@ -76,4 +83,11 @@ mod test {
             |context, input| test_parser.map(|_| ()).parse(context, input),
         )
     }
+
+    #[test]
+    fn char_satsify_test() {
+        parser_test_helper(ParserContext::new_with_str("abc", ()), &'a', |c, i| {
+            char_satisfy(char::is_ascii).parse(c, i)
+        });
+    }
 }

src/text/string_parsers.rs

@@ -0,0 +1,37 @@
+use crate::parser::{FailedParserResult, Parser, ParserContext, ParserResult};
+use std::cell::RefCell;
+use std::rc::Rc;
+
+pub struct StringParser {
+    pub(crate) str: &'static str,
+}
+
+impl<'a, TContext> Parser<'a, char, &'a [char], TContext> for StringParser {
+    fn parse(
+        &self,
+        _: Rc<RefCell<ParserContext<char, TContext>>>,
+        input: &'a [char],
+    ) -> ParserResult<'a, char, &'a [char]> {
+        let length = self.str.chars().count();
+        if input.len() < length {
+            return Err(FailedParserResult::new(
+                input,
+                format!("Failed to get enough elements for string '{}'.", self.str),
+            ));
+        }
+
+        if (&input[..length])
+            .iter()
+            .zip(self.str.chars())
+            .map(|(x, y)| *x == y)
+            .all(|x| x)
+        {
+            Ok((&input[length..], &input[..length]))
+        } else {
+            Err(FailedParserResult::new(
+                input,
+                format!("Input is not string '{}'", self.str),
+            ))
+        }
+    }
+}