Parse - Handle `do catch` (aka `try`)

7 files changed, 66 insertions, 0 deletions

diff --git a/src/ast/dump.cpp b/src/ast/dump.cpp
index 94ad6271..f0bdfa11 100644
--- a/src/ast/dump.cpp
+++ b/src/ast/dump.cpp
@@ -71,6 +71,10 @@ public:
         dec_indent();
         m_os << indent() << "}";
     }
+    virtual void visit(AST::ExprNode_Try& n) override {
+        m_os << "try ";
+        AST::NodeVisitor::visit(n.m_inner);
+    }
     virtual void visit(AST::ExprNode_Macro& n) override {
         m_expr_root = false;
         m_os << n.m_name << "!( /* TODO: Macro TT */ )";
diff --git a/src/ast/expr.cpp b/src/ast/expr.cpp
index 5111bad6..dc006212 100644
--- a/src/ast/expr.cpp
+++ b/src/ast/expr.cpp
@@ -93,6 +93,12 @@ NODE(ExprNode_Block, {
     return NEWNODE(ExprNode_Block, m_is_unsafe, m_yields_final_value, mv$(nodes), m_local_mod);
 })
 
+NODE(ExprNode_Try, {
+    os << "try " << *m_inner;
+},{
+    return NEWNODE(ExprNode_Try, m_inner->clone());
+})
+
 NODE(ExprNode_Macro, {
     os << m_name << "!";
     if( m_ident.size() > 0 )
@@ -471,6 +477,9 @@ NV(ExprNode_Block, {
         visit(child);
     //UNINDENT();
 })
+NV(ExprNode_Try, {
+    visit(node.m_inner);
+})
 NV(ExprNode_Macro,
 {
     BUG(node.span(), "Hit unexpanded macro in expression - " << node);
diff --git a/src/ast/expr.hpp b/src/ast/expr.hpp
index f3981db5..7675b29a 100644
--- a/src/ast/expr.hpp
+++ b/src/ast/expr.hpp
@@ -74,6 +74,19 @@ struct ExprNode_Block:
     NODE_METHODS();
 };
 
+struct ExprNode_Try:
+    public ExprNode
+{
+    ExprNodeP   m_inner;
+
+    ExprNode_Try(ExprNodeP inner):
+        m_inner(mv$(inner))
+    {
+    }
+
+    NODE_METHODS();
+};
+
 struct ExprNode_Macro:
     public ExprNode
 {
@@ -633,6 +646,7 @@ public:
         virtual void visit(nt& node) = 0/*; \
         virtual void visit(const nt& node) = 0*/
     NT(ExprNode_Block);
+    NT(ExprNode_Try);
     NT(ExprNode_Macro);
     NT(ExprNode_Asm);
     NT(ExprNode_Flow);
@@ -678,6 +692,7 @@ public:
         virtual void visit(nt& node) override;/* \
         virtual void visit(const nt& node) override*/
     NT(ExprNode_Block);
+    NT(ExprNode_Try);
     NT(ExprNode_Macro);
     NT(ExprNode_Asm);
     NT(ExprNode_Flow);
diff --git a/src/expand/mod.cpp b/src/expand/mod.cpp
index 751b14eb..8e36bd95 100644
--- a/src/expand/mod.cpp
+++ b/src/expand/mod.cpp
@@ -547,6 +547,9 @@ struct CExpandExpr:
 
         this->modstack = mv$(prev_modstack);
     }
+    void visit(::AST::ExprNode_Try& node) override {
+        this->visit_nodelete(node, node.m_inner);
+    }
     void visit(::AST::ExprNode_Asm& node) override {
         for(auto& v : node.m_output)
             this->visit_nodelete(node, v.value);
diff --git a/src/expand/proc_macro.cpp b/src/expand/proc_macro.cpp
index 3f26c648..f0f28f5a 100644
--- a/src/expand/proc_macro.cpp
+++ b/src/expand/proc_macro.cpp
@@ -516,6 +516,9 @@ namespace {
             TODO(sp, "");
             m_pmi.send_symbol("}");
         }
+        void visit(::AST::ExprNode_Try& node) {
+            TODO(sp, "ExprNode_Try");
+        }
         void visit(::AST::ExprNode_Macro& node) {
             TODO(sp, "ExprNode_Macro");
         }
diff --git a/src/hir/from_ast_expr.cpp b/src/hir/from_ast_expr.cpp
index 23797382..7d676bf8 100644
--- a/src/hir/from_ast_expr.cpp
+++ b/src/hir/from_ast_expr.cpp
@@ -47,6 +47,9 @@ struct LowerHIR_ExprNode_Visitor:
 
         m_rv.reset( static_cast< ::HIR::ExprNode*>(rv) );
     }
+    virtual void visit(::AST::ExprNode_Try& v) override {
+        TODO(v.span(), "Handle _Try");
+    }
     virtual void visit(::AST::ExprNode_Macro& v) override {
         BUG(v.span(), "Hit ExprNode_Macro");
     }
diff --git a/src/parse/expr.cpp b/src/parse/expr.cpp
index 6e18f0eb..6cc94d74 100644
--- a/src/parse/expr.cpp
+++ b/src/parse/expr.cpp
@@ -254,6 +254,7 @@ ExprNodeP Parse_ExprBlockLine(TokenStream& lex, bool *add_silence)
         case TOK_BRACE_OPEN:
             { PUTBACK(tok, lex); ret = Parse_ExprBlockNode(lex); }
 
+            // If the block is followed by `.` or `?`, it's actually an expression!
             if( lex.lookahead(0) == TOK_DOT || lex.lookahead(0) == TOK_QMARK ) {
                 lex.putback( Token(Token::TagTakeIP(), InterpolatedFragment(InterpolatedFragment::EXPR, ret.release())) );
                 return Parse_ExprBlockLine_Stmt(lex, *add_silence);
@@ -470,6 +471,17 @@ ExprNodeP Parse_Expr_Match(TokenStream& lex)
     return NEWNODE( AST::ExprNode_Match, ::std::move(switch_val), ::std::move(arms) );
 }
 
+/// "do catch" block
+ExprNodeP Parse_Expr_Try(TokenStream& lex)
+{
+    TRACE_FUNCTION;
+    //Token   tok;
+
+    auto inner = Parse_ExprBlockNode(lex);
+    //TODO(lex.point_span(), "do catch");
+    return NEWNODE(AST::ExprNode_Try, ::std::move(inner));
+}
+
 /// Parses the 'stmt' fragment specifier
 /// - Flow control
 /// - Expressions
@@ -1126,6 +1138,23 @@ ExprNodeP Parse_ExprVal(TokenStream& lex)
         return Parse_WhileStmt(lex, "");
     case TOK_RWORD_FOR:
         return Parse_ForStmt(lex, "");
+    case TOK_RWORD_DO:
+        if( TARGETVER_1_29 )
+        {
+            // `do catch` - stabilised later as `try`
+            if( GET_TOK(tok, lex) == TOK_IDENT && tok.str() == "catch" )
+            {
+                return Parse_Expr_Try(lex);
+            }
+            else
+            {
+                throw ParseError::Unexpected(lex, tok);
+            }
+        }
+        else
+        {
+            throw ParseError::Unexpected(lex, tok);
+        }
     case TOK_RWORD_MATCH:
         return Parse_Expr_Match(lex);
     case TOK_RWORD_IF: