Fix repeated && and express precedence in grammar

GRAMMAR.md

@@ -90,13 +90,17 @@ import        : 'import' '?'? string? eol
 
 module        : 'mod' '?'? NAME string? eol
 
-expression    : 'if' condition '{' expression '}' 'else' '{' expression '}'
+expression    : disjunct || expression
+              | disjunct
+
+disjunct      : conjunct && disjunct
+              | conjunct
+
+conjunct      : 'if' condition '{' expression '}' 'else' '{' expression '}'
               | 'assert' '(' condition ',' expression ')'
               | '/' expression
               | value '/' expression
               | value '+' expression
-              | value '&&' expression
-              | value '||' expression
               | value
 
 condition     : expression '==' expression

src/parser.rs

@@ -537,7 +537,7 @@ impl<'run, 'src> Parser<'run, 'src> {
 
     let disjunct = if self.accepted(AmpersandAmpersand)? {
       let lhs = conjunct.into();
-      let rhs = self.parse_conjunct()?.into();
+      let rhs = self.parse_disjunct()?.into();
       Expression::And { lhs, rhs }
     } else {
       conjunct

tests/and_or.rs

@@ -56,3 +56,9 @@ fn and_has_higher_precedence_than_or() {
   evaluate("('' && 'foo') || 'bar'", "bar");
   evaluate("'' && 'foo' || 'bar'", "bar");
 }
+
+#[test]
+fn misc() {
+  evaluate("'' || '' || '' || '' || 'foo'", "foo");
+  evaluate("'foo' && 'foo' && 'foo' && 'foo' && 'bar'", "bar");
+}