Merge pull request #132 from adharshkamath/invariants-grammar

Added invariants grammar

Author: shubhamugare

syncode/parsers/grammars/invariants.lark

@@ -0,0 +1,48 @@
+start: invariants
+
+invariants: (invariant /\n+/)+ -> multiple_invariants
+
+invariant: "loop" /\s+/ "invariant" /\s+/ pred ";" -> invariant
+
+STRING: /"([^"\\]|\\.)*"/
+
+INTEGER: /[0-9]+/
+
+REAL: /[0-9]+\.[0-9]+/
+
+CHAR: /'([^'\\]|\\.)'/
+
+TRUE: "\true"
+
+FALSE: "\false"
+
+IDENTIFIER: /[a-zA-Z_][a-zA-Z0-9_]*/
+
+unary_logic_op: "~" 
+
+bin_logic_op: "&&" | "||" | "=>" | "<=>" 
+
+rel_arith_op: "==" | "!=" | "<" | "<=" | ">" | ">="
+
+unary_arith_op: "-"
+
+bin_arith_op: "+" | "-" | "*" | "/" | "%" | "^"
+
+expr: INTEGER 
+    | REAL 
+    | CHAR 
+    | STRING 
+    | IDENTIFIER 
+    | IDENTIFIER /\s+/ "(" /\s+/ expr /\s+/ ("," /\s+/ expr)* /\s+/ ")"
+    | "(" /\s+/ expr /\s+/ ")" 
+    | unary_arith_op /\s+/ expr 
+    | expr /\s+/ bin_arith_op /\s+/ expr 
+    | expr /\s+/ "?" /\s+/ expr /\s+/ ":" /\s+/ expr
+
+pred: TRUE 
+    | FALSE 
+    | "(" /\s+/ pred /\s+/ ")"
+    | expr
+    | unary_logic_op /\s+/ pred 
+    | pred /\s+/ bin_logic_op /\s+/ pred 
+    | expr /\s+/ rel_arith_op /\s+/ expr