ltcc: parsing of double quoted strings

use double quotes in examples

lib-ltcore/src/expr.rs

@@ -41,10 +41,14 @@ pub type TypeTag = Result<laddertypes::TypeTerm, TypeError>;
 
 #[derive(Clone, Debug)]
 pub enum LTExpr {
-    Literal {
+    WordLiteral {
         typ: Option<TypeTag>,
         val: tisc::VM_Word,
     },
+    StringLiteral {
+        region: InputRegionTag,
+        value: String,
+    },
     Symbol {
         region: InputRegionTag,
         typ: Option<TypeTag>,
@@ -82,7 +86,7 @@ impl LTExpr {
     }
 */
     pub fn lit_uint(val: u64) -> Self {
-        LTExpr::Literal {
+        LTExpr::WordLiteral {
             typ: None, //typectx.write().unwrap().parse("ℤ_2^64~machine::UInt64~machine::Word").expect("parse typeterm"),
             val: val as tisc::VM_Word,
         }

lib-ltcore/src/lexer.rs

@@ -6,7 +6,7 @@ pub enum LTIRToken {
     Num(i64),
 
     // SingleQuote(String),
-    // DoubleQuote(String),
+    DoubleQuote(String),
     // TripleQuote(String),
     Lambda,
     MapsTo,
@@ -25,6 +25,7 @@ pub enum LTIRToken {
 pub enum LexError {
     InvalidDigit,
     InvalidChar,
+    UnexpectedEnd
 }
 
 #[derive(PartialEq, Eq, Clone, Debug)]
@@ -35,6 +36,7 @@ pub enum LexerState {
     Sym(String),
     Num(i64),
     Char(Option<char>),
+    DoubleQuote(String)
 }
 
 impl LexerState {
@@ -46,6 +48,7 @@ impl LexerState {
             LexerState::Sym(s) => Some(LTIRToken::Symbol(s)),
             LexerState::Num(n) => Some(LTIRToken::Num(n)),
             LexerState::Char(c) => Some(LTIRToken::Char(c?)),
+            LexerState::DoubleQuote(s) => Some(LTIRToken::DoubleQuote(s))
         }
     }
 }
@@ -196,6 +199,12 @@ where
                             }
                         }
                     }
+                    '\"' => {
+                        self.chars.next();
+                        self.position += 1;
+                        region.end += 1;
+                        state = LexerState::DoubleQuote(String::new());
+                    }
                     c => {
                         if c.is_whitespace() {
                             self.chars.next();
@@ -242,6 +251,36 @@ where
                     }
                 }
 
+                LexerState::DoubleQuote(val) => {
+                    match self.chars.next() {
+                        Some('\"') => {
+                            self.position += 1;
+                            region.end +=1;
+                            break;
+                        }
+                        Some('\\') => {
+                            match self.chars.next() {
+                                Some('0') => {
+                                    val.push('\0');
+                                }
+                                Some('n') => {
+                                    val.push('\n');
+                                }
+                                Some('\\') => {
+                                    val.push('\\');
+                                }
+                                _ => {}
+                            }
+                        }
+                        Some(c) => {
+                            val.push(c);
+                        }
+                        None => {
+                            return Some((region, Err(LexError::UnexpectedEnd)))
+                        }
+                    }
+                }
+
                 LexerState::Char(val) => {
                     self.position += 2;
                     region.end += 2;
@@ -325,7 +364,6 @@ where
                                     return Some((region, Err(LexError::InvalidDigit)));
                                 }
                             }
-
                             _ => {}
                         }
                     }
@@ -363,3 +401,4 @@ mod tests {
         }
     }
 }
+

lib-ltcore/src/parser.rs

@@ -345,6 +345,12 @@ where It: Iterator<Item = (InputRegionTag, Result<LTIRToken, LexError>)>
             Ok(LTIRToken::StatementSep) => {
                 break;
             }
+            Ok(LTIRToken::DoubleQuote(s)) => {
+                let region = region.clone();
+                let value = s.clone();
+                tokens.next();
+                children.push(LTExpr::StringLiteral{ region, value });
+            }
             Ok(LTIRToken::Symbol(name)) => match name.as_str() {
                 "if" => {
                     tokens.next();
@@ -404,6 +410,7 @@ where It: Iterator<Item = (InputRegionTag, Result<LTIRToken, LexError>)>
 
 
 mod tests {
+    use crate::parser::LTExpr;
     use std::sync::{Arc, RwLock};
     
     #[test]
@@ -421,6 +428,19 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_parse_double_quote() {
+        let mut lexer = crate::lexer::LTIRLexer::from("\"test\"".chars()).peekable();
+        let typectx = Arc::new(RwLock::new(laddertypes::dict::TypeDict::new()));
+        let expr = crate::parser::parse_expr( &typectx, &mut lexer );
+
+        assert_eq!(
+            expr,
+            Ok(LTExpr::DoubleQuote("testlo".into()))
+        );
+    }
+
+
     #[test]
     fn test_parse_typed_atomic_binding() {
         let mut lexer = crate::lexer::LTIRLexer::from("x:T".chars()).peekable();

lib-ltcore/src/procedure_compiler.rs

@@ -225,7 +225,13 @@ impl ProcedureCompiler {
                     );
                 }
             },
-            LTExpr::Literal { typ, val } => {
+            LTExpr::StringLiteral { region, value } => {
+                self.asm = self.asm.lit(0);
+                for c in value.chars().rev() {
+                    self.asm = self.asm.lit(c as i64);
+                }
+            }
+            LTExpr::WordLiteral { typ, val } => {
                 self.asm = self.asm.lit(*val);
             }
             LTExpr::Application { typ, head, body } => {                

lt-stdlib/int.lt

@@ -16,19 +16,3 @@ export {
     let int-max = λ{ a:ℤ~machine.Int64; b:ℤ~machine.Int64; } ↦ if( int-gt a b ) { a; } else { b; };
 };
 
-
-/* syntax ambiguity */
-
-let f'0 = λx:A -> B ↦ { ... };
-
-/* could be interpreted as .. */
-let f'1 = λ{x: A -> B} ↦ {};
-/* ..or.. */
-let f'2 = λx:A ↦ B:{};
-
-
-do {
-	!a 10;
-	!b 20;
-}
-

main.lt

@@ -1,5 +1,6 @@
-{
+export {
-    print-nullterm 'H''e''l''l''o'' ''W''o''r''l''d''!''\n''\0';
+let main = λ{} ↦ {
+    print-nullterm "Hello World!\n";
 
     /*  test ratio
      */
@@ -32,5 +33,6 @@
         '\n''\0';
 
     uint-machine-to-posint 16 256;
+};
 }