1st draft for string parsing and ast type

- currently uses back quotes "`" for strings, change later
- ast -> asg unimplemented, strings need to be processed on
canonicalization stage

asg/src/expression/constant.rs

@@ -220,6 +220,9 @@ impl<'a> FromAst<'a, leo_ast::ValueExpression> for Constant<'a> {
                     value: ConstValue::Int(ConstInt::parse(int_type, value, span)?),
                 }
             }
+            String(_str_type, _value) => {
+                unimplemented!("strings do not exist on ASG level")
+            }
         })
     }
 }

ast/src/expression/value.rs

@@ -33,6 +33,7 @@ pub enum ValueExpression {
         #[serde(with = "crate::common::tendril_json")] StrTendril,
         Span,
     ),
+    String(Vec<char>, Span),
 }
 
 impl fmt::Display for ValueExpression {
@@ -46,6 +47,12 @@ impl fmt::Display for ValueExpression {
             Implicit(implicit, _) => write!(f, "{}", implicit),
             Integer(value, type_, _) => write!(f, "{}{}", value, type_),
             Group(group) => write!(f, "{}", group),
+            String(char_vec, _) => {
+                for character in char_vec {
+                    write!(f, "{}", character)?
+                }
+                Ok(())
+            }
         }
     }
 }
@@ -59,7 +66,8 @@ impl Node for ValueExpression {
             | Char(_, span)
             | Field(_, span)
             | Implicit(_, span)
-            | Integer(_, _, span) => span,
+            | Integer(_, _, span) //  => span,
+            | String(_, span) => span,
             Group(group) => match &**group {
                 GroupValue::Single(_, span) | GroupValue::Tuple(GroupTuple { span, .. }) => span,
             },
@@ -74,7 +82,8 @@ impl Node for ValueExpression {
             | Char(_, span)
             | Field(_, span)
             | Implicit(_, span)
-            | Integer(_, _, span) => *span = new_span,
+            | Integer(_, _, span) // => *span = new_span,
+            | String(_, span) => *span = new_span,
             Group(group) => match &mut **group {
                 GroupValue::Single(_, span) | GroupValue::Tuple(GroupTuple { span, .. }) => *span = new_span,
             },

parser/src/parser/expression.rs

@@ -690,6 +690,7 @@ impl ParserContext {
             Token::False => Expression::Value(ValueExpression::Boolean("false".into(), span)),
             Token::AddressLit(value) => Expression::Value(ValueExpression::Address(value, span)),
             Token::CharLit(value) => Expression::Value(ValueExpression::Char(value, span)),
+            Token::QuotedString(value) => Expression::Value(ValueExpression::String(value, span)),
             Token::LeftParen => self.parse_tuple_expression(&span)?,
             Token::LeftSquare => self.parse_array_expression(&span)?,
             Token::Ident(name) => {

parser/src/tokenizer/lexer.rs

@@ -235,6 +235,16 @@ impl Token {
         let input = input_tendril[..].as_bytes();
         match input[0] {
             x if x.is_ascii_whitespace() => return (1, None),
+            b'`' => {
+                let mut collect: Vec<char> = Vec::new();
+                for (i, char_bytes) in input.iter().enumerate().skip(1) {
+                    if *char_bytes == b'`' {
+                        return (i + 1, Some(Token::QuotedString(collect)));
+                    }
+
+                    collect.push(std::char::from_u32(*char_bytes as u32).unwrap());
+                }
+            }
             b'"' => {
                 let mut i = 1;
                 let mut in_escape = false;

parser/src/tokenizer/mod.rs

@@ -259,6 +259,6 @@ mod tests {
             let original = &raw[*start + token.span.col_start - 1..*stop + token.span.col_stop - 1];
             assert_eq!(original, &token_raw);
         }
-        println!("{}", serde_json::to_string_pretty(&tokens).unwrap());
+        // println!("{}", serde_json::to_string_pretty(&tokens).unwrap());
     }
 }

parser/src/tokenizer/token.rs

@@ -42,6 +42,7 @@ pub enum Token {
     CommentLine(#[serde(with = "leo_ast::common::tendril_json")] StrTendril),
     CommentBlock(#[serde(with = "leo_ast::common::tendril_json")] StrTendril),
     FormatString(Vec<FormatStringPart>),
+    QuotedString(Vec<char>),
     Ident(#[serde(with = "leo_ast::common::tendril_json")] StrTendril),
     Int(#[serde(with = "leo_ast::common::tendril_json")] StrTendril),
     True,
@@ -215,6 +216,13 @@ impl fmt::Display for Token {
                 }
                 write!(f, "\"")
             }
+            QuotedString(content) => {
+                write!(f, "\"")?;
+                for character in content {
+                    write!(f, "{}", character)?;
+                }
+                write!(f, "\"")
+            }
             Ident(s) => write!(f, "{}", s),
             Int(s) => write!(f, "{}", s),
             True => write!(f, "true"),

tests/expectations/parser/parser/expression/string.leo.out

@@ -0,0 +1,63 @@
+---
+namespace: ParseExpression
+expectation: Pass
+outputs:
+  - Value:
+      String:
+        - - s
+          - t
+          - r
+          - i
+          - n
+          - g
+        - line_start: 1
+          line_stop: 1
+          col_start: 1
+          col_stop: 9
+          path: test
+          content: "`string`"
+  - Value:
+      String:
+        - - a
+          - n
+          - o
+          - t
+          - h
+          - e
+          - r
+          - " "
+          - "{"
+          - " "
+          - "}"
+          - " "
+          - s
+          - t
+          - r
+          - i
+          - n
+          - g
+        - line_start: 1
+          line_stop: 1
+          col_start: 1
+          col_stop: 21
+          path: test
+          content: "`another { } string`"
+  - Value:
+      String:
+        - - "{"
+          - " "
+          - "\\"
+          - " "
+          - "]"
+          - " "
+          - "["
+          - " "
+          - ;
+          - " "
+          - a
+        - line_start: 1
+          line_stop: 1
+          col_start: 1
+          col_stop: 14
+          path: test
+          content: "`{ \\ ] [ ; a`"

tests/parser/expression/string.leo

@@ -0,0 +1,10 @@
+/*
+namespace: ParseExpression
+expectation: Pass
+*/
+
+`string`
+
+`another { } string`
+
+`{ \ ] [ ; a`