From 589411f0de41fd351c8a0ec712cd7eacef98036d Mon Sep 17 00:00:00 2001
From: Gagandeep Singh <gdp.1807@gmail.com>
Date: Mon, 18 Oct 2021 17:37:51 +0530
Subject: [PATCH] Added BOZ

---
 grammar/ASR.asdl                            |  3 +++
 src/lfortran/asr_utils.h                    |  1 +
 src/lfortran/semantics/ast_common_visitor.h | 21 +++++++++++++++++++++
 3 files changed, 25 insertions(+)

diff --git a/grammar/ASR.asdl b/grammar/ASR.asdl
index 51eaef0608..02280ba9f1 100644
--- a/grammar/ASR.asdl
+++ b/grammar/ASR.asdl
@@ -205,6 +205,7 @@ expr
     | ConstantComplex(float re, float im, ttype type)
     | ConstantLogical(bool value, ttype type)
     | ConstantString(string s, ttype type)
+    | BOZ(string s, boz boz_type, ttype? type)
     | Var(symbol v)
     | ArrayRef(symbol v, array_index* args, ttype type, expr? value)
     | DerivedRef(expr v, symbol m, ttype type, expr? value)
@@ -242,6 +243,8 @@ strop = Concat
 
 cmpop = Eq | NotEq | Lt | LtE | Gt | GtE
 
+boz = Binary | Hex | Octal
+
 cast_kind
     = RealToInteger
     | IntegerToReal
diff --git a/src/lfortran/asr_utils.h b/src/lfortran/asr_utils.h
index 6fcd3efa06..8a4a724a07 100644
--- a/src/lfortran/asr_utils.h
+++ b/src/lfortran/asr_utils.h
@@ -97,6 +97,7 @@ static inline ASR::ttype_t* expr_type(const ASR::expr_t *f)
         case ASR::exprType::StrOp: { return ((ASR::StrOp_t*)f)->m_type; }
         case ASR::exprType::ImpliedDoLoop: { return ((ASR::ImpliedDoLoop_t*)f)->m_type; }
         case ASR::exprType::DerivedTypeConstructor: { return ((ASR::DerivedTypeConstructor_t*)f)->m_type; }
+        case ASR::exprType::BOZ: { return ((ASR::BOZ_t*)f)->m_type; }
         default : throw LFortranException("Not implemented");
     }
 }
diff --git a/src/lfortran/semantics/ast_common_visitor.h b/src/lfortran/semantics/ast_common_visitor.h
index 161d405d02..ce4410c02f 100644
--- a/src/lfortran/semantics/ast_common_visitor.h
+++ b/src/lfortran/semantics/ast_common_visitor.h
@@ -1210,6 +1210,27 @@ class CommonVisitor : public AST::BaseVisitor<Derived> {
         tmp = ASR::make_ConstantString_t(al, x.base.base.loc, x.m_s, type);
     }
 
+    void visit_BOZ(const AST::BOZ_t& x) {
+        LFortran::Str boz_content;
+        std::string s = x.m_s; 
+        boz_content.from_str(al, s.substr(1));
+        ASR::bozType boz_type;
+        if( s[0] == 'b' || s[0] == 'B' ) {
+            boz_type = ASR::bozType::Binary;
+        } else if( s[0] == 'z' || s[0] == 'Z' ) {
+            boz_type = ASR::bozType::Hex;
+        } else if( s[0] == 'o' || s[0] == 'O' ) {
+            boz_type = ASR::bozType::Octal;
+        } else {
+            throw SemanticError(R"""(Only 'b', 'o' and 'z' 
+                                are accepted as prefixes of 
+                                BOZ literal constants.)""", 
+                                x.base.base.loc);
+        }
+        tmp = ASR::make_BOZ_t(al, x.base.base.loc, boz_content.c_str(al),
+                                boz_type, nullptr);
+    }
+
     void visit_Num(const AST::Num_t &x) {
         int ikind = 4;
         if (x.m_kind) {