fix: examples precedence

examples/calculator.rs

@@ -31,7 +31,7 @@ fn main() -> Result<(), ()> {
                     let ast = parse_tree.as_abstract_syntax_tree();
 
                     println!("Abstract Syntax Tree:");
-                    println!("{ast:?}");
+                    println!("{ast:#?}");
 
                     println!("Evaluated:");
                     println!("{}", eval(&ast));

src/lib.rs

@@ -15,7 +15,8 @@
 //! It provides you:
 //! - A library for defining any
 //!  [context-free grammar](https://en.wikipedia.org/wiki/Context-free_grammar),
-//! - A [Lexical analysis](https://en.wikipedia.org/wiki/Lexical_analysis) module,
+//! - A [Lexical analysis](https://en.wikipedia.org/wiki/Lexical_analysis)
+//!   module,
 //! - And facilities for building interpreters or compilers of the language.
 //!
 //! With Santiago you have everything that is needed
@@ -444,7 +445,7 @@
 //!
 //! let ast = parse_tree.as_abstract_syntax_tree();
 //!
-//! assert_eq!(eval(&ast), -6);
+//! assert_eq!(eval(&ast), -5);
 //! ```
 //! 
 //! ## JavaScript string interpolations
@@ -562,8 +563,7 @@
 //! # Next steps
 //!
 //! This tutorial ends here,
-//! you should now have everything to lex,
-//! parse, and as_abstract_syntax_tree the world,
+//! you should now have everything to lex and parse the world,
 //! and build your own programming languages, compilers and interpreters!
 //!
 //! You can checkout more examples in the tests folder:

tests/calculator/cases/example/earley

@@ -1,173 +1,158 @@
 0
   "Γ" := rules • "expr" [0-0]
-  "expr" := rules • "bin_op" [0-0]
   "expr" := rules • "int" [0-0]
-  "bin_op" := rules • "expr" "add" "expr" [0-0]
-  "bin_op" := rules • "expr" "subtract" "expr" [0-0]
-  "bin_op" := rules • "expr" "multiply" "expr" [0-0]
-  "bin_op" := rules • "expr" "divide" "expr" [0-0]
+  "expr" := rules • "expr" "add" "expr" [0-0]
+  "expr" := rules • "expr" "subtract" "expr" [0-0]
+  "expr" := rules • "expr" "multiply" "expr" [0-0]
+  "expr" := rules • "expr" "divide" "expr" [0-0]
   "int" := lexemes • "INT" [0-0]
 1
   "int" := lexemes "INT" • [0-1]
   "expr" := rules "int" • [0-1]
   "Γ" := rules "expr" • [0-1]
-  "bin_op" := rules "expr" • "add" "expr" [0-1]
-  "bin_op" := rules "expr" • "subtract" "expr" [0-1]
-  "bin_op" := rules "expr" • "multiply" "expr" [0-1]
-  "bin_op" := rules "expr" • "divide" "expr" [0-1]
+  "expr" := rules "expr" • "add" "expr" [0-1]
+  "expr" := rules "expr" • "subtract" "expr" [0-1]
+  "expr" := rules "expr" • "multiply" "expr" [0-1]
+  "expr" := rules "expr" • "divide" "expr" [0-1]
   "add" := lexemes • "+" [1-1]
 2
   "add" := lexemes "+" • [1-2]
-  "bin_op" := rules "expr" "add" • "expr" [0-2]
-  "expr" := rules • "bin_op" [2-2]
+  "expr" := rules "expr" "add" • "expr" [0-2]
   "expr" := rules • "int" [2-2]
-  "bin_op" := rules • "expr" "add" "expr" [2-2]
-  "bin_op" := rules • "expr" "subtract" "expr" [2-2]
-  "bin_op" := rules • "expr" "multiply" "expr" [2-2]
-  "bin_op" := rules • "expr" "divide" "expr" [2-2]
+  "expr" := rules • "expr" "add" "expr" [2-2]
+  "expr" := rules • "expr" "subtract" "expr" [2-2]
+  "expr" := rules • "expr" "multiply" "expr" [2-2]
+  "expr" := rules • "expr" "divide" "expr" [2-2]
   "int" := lexemes • "INT" [2-2]
 3
   "int" := lexemes "INT" • [2-3]
   "expr" := rules "int" • [2-3]
-  "bin_op" := rules "expr" "add" "expr" • [0-3]
-  "bin_op" := rules "expr" • "add" "expr" [2-3]
-  "bin_op" := rules "expr" • "subtract" "expr" [2-3]
-  "bin_op" := rules "expr" • "multiply" "expr" [2-3]
-  "bin_op" := rules "expr" • "divide" "expr" [2-3]
-  "expr" := rules "bin_op" • [0-3]
-  "multiply" := lexemes • "*" [3-3]
+  "expr" := rules "expr" "add" "expr" • [0-3]
+  "expr" := rules "expr" • "add" "expr" [2-3]
+  "expr" := rules "expr" • "subtract" "expr" [2-3]
+  "expr" := rules "expr" • "multiply" "expr" [2-3]
+  "expr" := rules "expr" • "divide" "expr" [2-3]
   "Γ" := rules "expr" • [0-3]
-  "bin_op" := rules "expr" • "add" "expr" [0-3]
-  "bin_op" := rules "expr" • "subtract" "expr" [0-3]
-  "bin_op" := rules "expr" • "multiply" "expr" [0-3]
-  "bin_op" := rules "expr" • "divide" "expr" [0-3]
+  "expr" := rules "expr" • "add" "expr" [0-3]
+  "expr" := rules "expr" • "subtract" "expr" [0-3]
+  "expr" := rules "expr" • "multiply" "expr" [0-3]
+  "expr" := rules "expr" • "divide" "expr" [0-3]
+  "multiply" := lexemes • "*" [3-3]
 4
   "multiply" := lexemes "*" • [3-4]
-  "bin_op" := rules "expr" "multiply" • "expr" [2-4]
-  "bin_op" := rules "expr" "multiply" • "expr" [0-4]
-  "expr" := rules • "bin_op" [4-4]
+  "expr" := rules "expr" "multiply" • "expr" [2-4]
+  "expr" := rules "expr" "multiply" • "expr" [0-4]
   "expr" := rules • "int" [4-4]
-  "bin_op" := rules • "expr" "add" "expr" [4-4]
-  "bin_op" := rules • "expr" "subtract" "expr" [4-4]
-  "bin_op" := rules • "expr" "multiply" "expr" [4-4]
-  "bin_op" := rules • "expr" "divide" "expr" [4-4]
+  "expr" := rules • "expr" "add" "expr" [4-4]
+  "expr" := rules • "expr" "subtract" "expr" [4-4]
+  "expr" := rules • "expr" "multiply" "expr" [4-4]
+  "expr" := rules • "expr" "divide" "expr" [4-4]
   "int" := lexemes • "INT" [4-4]
 5
   "int" := lexemes "INT" • [4-5]
   "expr" := rules "int" • [4-5]
-  "bin_op" := rules "expr" "multiply" "expr" • [2-5]
-  "bin_op" := rules "expr" "multiply" "expr" • [0-5]
-  "bin_op" := rules "expr" • "add" "expr" [4-5]
-  "bin_op" := rules "expr" • "subtract" "expr" [4-5]
-  "bin_op" := rules "expr" • "multiply" "expr" [4-5]
-  "bin_op" := rules "expr" • "divide" "expr" [4-5]
-  "expr" := rules "bin_op" • [2-5]
-  "expr" := rules "bin_op" • [0-5]
-  "divide" := lexemes • "/" [5-5]
-  "bin_op" := rules "expr" "add" "expr" • [0-5]
-  "bin_op" := rules "expr" • "add" "expr" [2-5]
-  "bin_op" := rules "expr" • "subtract" "expr" [2-5]
-  "bin_op" := rules "expr" • "multiply" "expr" [2-5]
-  "bin_op" := rules "expr" • "divide" "expr" [2-5]
+  "expr" := rules "expr" "multiply" "expr" • [2-5]
+  "expr" := rules "expr" "multiply" "expr" • [0-5]
+  "expr" := rules "expr" • "add" "expr" [4-5]
+  "expr" := rules "expr" • "subtract" "expr" [4-5]
+  "expr" := rules "expr" • "multiply" "expr" [4-5]
+  "expr" := rules "expr" • "divide" "expr" [4-5]
+  "expr" := rules "expr" "add" "expr" • [0-5]
+  "expr" := rules "expr" • "add" "expr" [2-5]
+  "expr" := rules "expr" • "subtract" "expr" [2-5]
+  "expr" := rules "expr" • "multiply" "expr" [2-5]
+  "expr" := rules "expr" • "divide" "expr" [2-5]
   "Γ" := rules "expr" • [0-5]
-  "bin_op" := rules "expr" • "add" "expr" [0-5]
-  "bin_op" := rules "expr" • "subtract" "expr" [0-5]
-  "bin_op" := rules "expr" • "multiply" "expr" [0-5]
-  "bin_op" := rules "expr" • "divide" "expr" [0-5]
+  "expr" := rules "expr" • "add" "expr" [0-5]
+  "expr" := rules "expr" • "subtract" "expr" [0-5]
+  "expr" := rules "expr" • "multiply" "expr" [0-5]
+  "expr" := rules "expr" • "divide" "expr" [0-5]
+  "divide" := lexemes • "/" [5-5]
 6
   "divide" := lexemes "/" • [5-6]
-  "bin_op" := rules "expr" "divide" • "expr" [4-6]
-  "bin_op" := rules "expr" "divide" • "expr" [2-6]
-  "bin_op" := rules "expr" "divide" • "expr" [0-6]
-  "expr" := rules • "bin_op" [6-6]
+  "expr" := rules "expr" "divide" • "expr" [4-6]
+  "expr" := rules "expr" "divide" • "expr" [2-6]
+  "expr" := rules "expr" "divide" • "expr" [0-6]
   "expr" := rules • "int" [6-6]
-  "bin_op" := rules • "expr" "add" "expr" [6-6]
-  "bin_op" := rules • "expr" "subtract" "expr" [6-6]
-  "bin_op" := rules • "expr" "multiply" "expr" [6-6]
-  "bin_op" := rules • "expr" "divide" "expr" [6-6]
+  "expr" := rules • "expr" "add" "expr" [6-6]
+  "expr" := rules • "expr" "subtract" "expr" [6-6]
+  "expr" := rules • "expr" "multiply" "expr" [6-6]
+  "expr" := rules • "expr" "divide" "expr" [6-6]
   "int" := lexemes • "INT" [6-6]
 7
   "int" := lexemes "INT" • [6-7]
   "expr" := rules "int" • [6-7]
-  "bin_op" := rules "expr" "divide" "expr" • [4-7]
-  "bin_op" := rules "expr" "divide" "expr" • [2-7]
-  "bin_op" := rules "expr" "divide" "expr" • [0-7]
-  "bin_op" := rules "expr" • "add" "expr" [6-7]
-  "bin_op" := rules "expr" • "subtract" "expr" [6-7]
-  "bin_op" := rules "expr" • "multiply" "expr" [6-7]
-  "bin_op" := rules "expr" • "divide" "expr" [6-7]
-  "expr" := rules "bin_op" • [4-7]
-  "expr" := rules "bin_op" • [2-7]
-  "expr" := rules "bin_op" • [0-7]
-  "subtract" := lexemes • "-" [7-7]
-  "bin_op" := rules "expr" "multiply" "expr" • [2-7]
-  "bin_op" := rules "expr" "multiply" "expr" • [0-7]
-  "bin_op" := rules "expr" • "add" "expr" [4-7]
-  "bin_op" := rules "expr" • "subtract" "expr" [4-7]
-  "bin_op" := rules "expr" • "multiply" "expr" [4-7]
-  "bin_op" := rules "expr" • "divide" "expr" [4-7]
-  "bin_op" := rules "expr" "add" "expr" • [0-7]
-  "bin_op" := rules "expr" • "add" "expr" [2-7]
-  "bin_op" := rules "expr" • "subtract" "expr" [2-7]
-  "bin_op" := rules "expr" • "multiply" "expr" [2-7]
-  "bin_op" := rules "expr" • "divide" "expr" [2-7]
+  "expr" := rules "expr" "divide" "expr" • [4-7]
+  "expr" := rules "expr" "divide" "expr" • [2-7]
+  "expr" := rules "expr" "divide" "expr" • [0-7]
+  "expr" := rules "expr" • "add" "expr" [6-7]
+  "expr" := rules "expr" • "subtract" "expr" [6-7]
+  "expr" := rules "expr" • "multiply" "expr" [6-7]
+  "expr" := rules "expr" • "divide" "expr" [6-7]
+  "expr" := rules "expr" "multiply" "expr" • [2-7]
+  "expr" := rules "expr" "multiply" "expr" • [0-7]
+  "expr" := rules "expr" • "add" "expr" [4-7]
+  "expr" := rules "expr" • "subtract" "expr" [4-7]
+  "expr" := rules "expr" • "multiply" "expr" [4-7]
+  "expr" := rules "expr" • "divide" "expr" [4-7]
+  "expr" := rules "expr" "add" "expr" • [0-7]
+  "expr" := rules "expr" • "add" "expr" [2-7]
+  "expr" := rules "expr" • "subtract" "expr" [2-7]
+  "expr" := rules "expr" • "multiply" "expr" [2-7]
+  "expr" := rules "expr" • "divide" "expr" [2-7]
   "Γ" := rules "expr" • [0-7]
-  "bin_op" := rules "expr" • "add" "expr" [0-7]
-  "bin_op" := rules "expr" • "subtract" "expr" [0-7]
-  "bin_op" := rules "expr" • "multiply" "expr" [0-7]
-  "bin_op" := rules "expr" • "divide" "expr" [0-7]
+  "expr" := rules "expr" • "add" "expr" [0-7]
+  "expr" := rules "expr" • "subtract" "expr" [0-7]
+  "expr" := rules "expr" • "multiply" "expr" [0-7]
+  "expr" := rules "expr" • "divide" "expr" [0-7]
+  "subtract" := lexemes • "-" [7-7]
 8
   "subtract" := lexemes "-" • [7-8]
-  "bin_op" := rules "expr" "subtract" • "expr" [6-8]
-  "bin_op" := rules "expr" "subtract" • "expr" [4-8]
-  "bin_op" := rules "expr" "subtract" • "expr" [2-8]
-  "bin_op" := rules "expr" "subtract" • "expr" [0-8]
-  "expr" := rules • "bin_op" [8-8]
+  "expr" := rules "expr" "subtract" • "expr" [6-8]
+  "expr" := rules "expr" "subtract" • "expr" [4-8]
+  "expr" := rules "expr" "subtract" • "expr" [2-8]
+  "expr" := rules "expr" "subtract" • "expr" [0-8]
   "expr" := rules • "int" [8-8]
-  "bin_op" := rules • "expr" "add" "expr" [8-8]
-  "bin_op" := rules • "expr" "subtract" "expr" [8-8]
-  "bin_op" := rules • "expr" "multiply" "expr" [8-8]
-  "bin_op" := rules • "expr" "divide" "expr" [8-8]
+  "expr" := rules • "expr" "add" "expr" [8-8]
+  "expr" := rules • "expr" "subtract" "expr" [8-8]
+  "expr" := rules • "expr" "multiply" "expr" [8-8]
+  "expr" := rules • "expr" "divide" "expr" [8-8]
   "int" := lexemes • "INT" [8-8]
 9
   "int" := lexemes "INT" • [8-9]
   "expr" := rules "int" • [8-9]
-  "bin_op" := rules "expr" "subtract" "expr" • [6-9]
-  "bin_op" := rules "expr" "subtract" "expr" • [4-9]
-  "bin_op" := rules "expr" "subtract" "expr" • [2-9]
-  "bin_op" := rules "expr" "subtract" "expr" • [0-9]
-  "bin_op" := rules "expr" • "add" "expr" [8-9]
-  "bin_op" := rules "expr" • "subtract" "expr" [8-9]
-  "bin_op" := rules "expr" • "multiply" "expr" [8-9]
-  "bin_op" := rules "expr" • "divide" "expr" [8-9]
-  "expr" := rules "bin_op" • [6-9]
-  "expr" := rules "bin_op" • [4-9]
-  "expr" := rules "bin_op" • [2-9]
-  "expr" := rules "bin_op" • [0-9]
+  "expr" := rules "expr" "subtract" "expr" • [6-9]
+  "expr" := rules "expr" "subtract" "expr" • [4-9]
+  "expr" := rules "expr" "subtract" "expr" • [2-9]
+  "expr" := rules "expr" "subtract" "expr" • [0-9]
+  "expr" := rules "expr" • "add" "expr" [8-9]
+  "expr" := rules "expr" • "subtract" "expr" [8-9]
+  "expr" := rules "expr" • "multiply" "expr" [8-9]
+  "expr" := rules "expr" • "divide" "expr" [8-9]
+  "expr" := rules "expr" "divide" "expr" • [4-9]
+  "expr" := rules "expr" "divide" "expr" • [2-9]
+  "expr" := rules "expr" "divide" "expr" • [0-9]
+  "expr" := rules "expr" • "add" "expr" [6-9]
+  "expr" := rules "expr" • "subtract" "expr" [6-9]
+  "expr" := rules "expr" • "multiply" "expr" [6-9]
+  "expr" := rules "expr" • "divide" "expr" [6-9]
+  "expr" := rules "expr" "multiply" "expr" • [2-9]
+  "expr" := rules "expr" "multiply" "expr" • [0-9]
+  "expr" := rules "expr" • "add" "expr" [4-9]
+  "expr" := rules "expr" • "subtract" "expr" [4-9]
+  "expr" := rules "expr" • "multiply" "expr" [4-9]
+  "expr" := rules "expr" • "divide" "expr" [4-9]
+  "expr" := rules "expr" "add" "expr" • [0-9]
+  "expr" := rules "expr" • "add" "expr" [2-9]
+  "expr" := rules "expr" • "subtract" "expr" [2-9]
+  "expr" := rules "expr" • "multiply" "expr" [2-9]
+  "expr" := rules "expr" • "divide" "expr" [2-9]
+  "Γ" := rules "expr" • [0-9]
+  "expr" := rules "expr" • "add" "expr" [0-9]
+  "expr" := rules "expr" • "subtract" "expr" [0-9]
+  "expr" := rules "expr" • "multiply" "expr" [0-9]
+  "expr" := rules "expr" • "divide" "expr" [0-9]
   "add" := lexemes • "+" [9-9]
   "subtract" := lexemes • "-" [9-9]
   "multiply" := lexemes • "*" [9-9]
-  "divide" := lexemes • "/" [9-9]
-  "bin_op" := rules "expr" "divide" "expr" • [4-9]
-  "bin_op" := rules "expr" "divide" "expr" • [2-9]
-  "bin_op" := rules "expr" "divide" "expr" • [0-9]
-  "bin_op" := rules "expr" • "add" "expr" [6-9]
-  "bin_op" := rules "expr" • "subtract" "expr" [6-9]
-  "bin_op" := rules "expr" • "multiply" "expr" [6-9]
-  "bin_op" := rules "expr" • "divide" "expr" [6-9]
-  "bin_op" := rules "expr" "multiply" "expr" • [2-9]
-  "bin_op" := rules "expr" "multiply" "expr" • [0-9]
-  "bin_op" := rules "expr" • "add" "expr" [4-9]
-  "bin_op" := rules "expr" • "subtract" "expr" [4-9]
-  "bin_op" := rules "expr" • "multiply" "expr" [4-9]
-  "bin_op" := rules "expr" • "divide" "expr" [4-9]
-  "bin_op" := rules "expr" "add" "expr" • [0-9]
-  "bin_op" := rules "expr" • "add" "expr" [2-9]
-  "bin_op" := rules "expr" • "subtract" "expr" [2-9]
-  "bin_op" := rules "expr" • "multiply" "expr" [2-9]
-  "bin_op" := rules "expr" • "divide" "expr" [2-9]
-  "Γ" := rules "expr" • [0-9]
-  "bin_op" := rules "expr" • "add" "expr" [0-9]
-  "bin_op" := rules "expr" • "subtract" "expr" [0-9]
-  "bin_op" := rules "expr" • "multiply" "expr" [0-9]
-  "bin_op" := rules "expr" • "divide" "expr" [0-9]
+  "divide" := lexemes • "/" [9-9]

tests/calculator/cases/example/parse_trees

@@ -1,33 +1,29 @@
 ---
 Γ := rules "expr"
-  expr := rules "bin_op"
-    bin_op := rules "expr" "subtract" "expr"
-      expr := rules "bin_op"
-        bin_op := rules "expr" "divide" "expr"
-          expr := rules "bin_op"
-            bin_op := rules "expr" "multiply" "expr"
-              expr := rules "bin_op"
-                bin_op := rules "expr" "add" "expr"
-                  expr := rules "int"
-                    int := lexemes "INT"
-                      INT "1" (1, 1)
-                  add := lexemes "+"
-                    + "+" (1, 3)
-                  expr := rules "int"
-                    int := lexemes "INT"
-                      INT "2" (1, 5)
-              multiply := lexemes "*"
-                * "*" (1, 7)
-              expr := rules "int"
-                int := lexemes "INT"
-                  INT "3" (1, 9)
-          divide := lexemes "/"
-            / "/" (1, 11)
-          expr := rules "int"
-            int := lexemes "INT"
-              INT "6" (1, 13)
-      subtract := lexemes "-"
-        - "-" (1, 15)
+  expr := rules "expr" "subtract" "expr"
+    expr := rules "expr" "add" "expr"
       expr := rules "int"
         int := lexemes "INT"
-          INT "7" (1, 17)
+          INT "1" (1, 1)
+      add := lexemes "+"
+        + "+" (1, 3)
+      expr := rules "expr" "divide" "expr"
+        expr := rules "expr" "multiply" "expr"
+          expr := rules "int"
+            int := lexemes "INT"
+              INT "2" (1, 5)
+          multiply := lexemes "*"
+            * "*" (1, 7)
+          expr := rules "int"
+            int := lexemes "INT"
+              INT "3" (1, 9)
+        divide := lexemes "/"
+          / "/" (1, 11)
+        expr := rules "int"
+          int := lexemes "INT"
+            INT "6" (1, 13)
+    subtract := lexemes "-"
+      - "-" (1, 15)
+    expr := rules "int"
+      int := lexemes "INT"
+        INT "7" (1, 17)