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xo-parser: scaffolding eliminates exprstate::def_lhs_symbol

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This commit is contained in:
Roland Conybeare 2024-08-01 15:34:47 +10:00
commit 4e9b41645f
2 changed files with 27 additions and 45 deletions
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12
include/xo/parser/parser.hpp
View file

@ -6,6 +6,7 @@
#pragma once
#include "xo/expression/Expression.hpp"
#include "xo/expression/DefineExpr.hpp"
#include "xo/tokenizer/token.hpp"
#include <stack>
#include <stdexcept>
@ -47,13 +48,17 @@ namespace xo {
class exprstate {
public:
using Expression = xo::ast::Expression;
using DefineExprAccess = xo::ast::DefineExprAccess;
using exprtype = xo::ast::exprtype;
using token_type = token<char>;
using TypeDescr = xo::reflect::TypeDescr;
public:
exprstate() = default;
exprstate(exprstatetype exs_type) : exs_type_{exs_type} {}
exprstate(exprstatetype exs_type,
rp<DefineExprAccess> def_expr = nullptr)
: exs_type_{exs_type},
def_expr_{std::move(def_expr)} {}
static exprstate expect_toplevel_expression_sequence() {
return exprstate(exprstatetype::expect_toplevel_expression_sequence);
@ -132,10 +137,15 @@ namespace xo {
**/
exprstatetype exs_type_;
/** scaffold a define-expression here **/
rp<DefineExprAccess> def_expr_;
#ifdef OBSOLETE
/** e.g. foo in
* def foo : f64 = 1
**/
std::string def_lhs_symbol_;
#endif
/** e.g. f64 in
* def foo : f64 = 1
**/

60
src/parser/parser.cpp
View file

@ -258,7 +258,9 @@ namespace xo {
xtag("state", *this)));
}
p_stack->push_exprstate(exprstatetype::def_0);
p_stack->push_exprstate(exprstate(exprstatetype::def_0,
DefineExprAccess::make_empty()));
/* todo: replace:
* expect_symbol_or_function_signature()
*/
@ -367,6 +369,7 @@ namespace xo {
case exprstatetype::def_2:
this->exs_type_ = exprstatetype::def_3;
this->def_lhs_td_ = td;
return;
@ -585,11 +588,18 @@ namespace xo {
if (def_lhs_td_)
rhs_value = ConvertExpr::make(def_lhs_td_, rhs_value);
rp<DefineExprAccess> def_expr = this->def_expr_;
def_expr->assign_rhs(rhs_value);
#ifdef OBSOLETE
rp<Expression> def = DefineExpr::make(this->def_lhs_symbol_,
rhs_value);
#endif
p_stack->pop_exprstate();
p_stack->top_exprstate().on_expr(def,
p_stack->pop_exprstate(); /* NOT KOSHER. invalidates *this */
p_stack->top_exprstate().on_expr(def_expr,
p_stack,
p_emit_expr);
return;
@ -629,7 +639,8 @@ namespace xo {
return;
case exprstatetype::def_0:
this->exs_type_ = exprstatetype::def_1;
this->def_lhs_symbol_ = symbol_name;
this->def_expr_->assign_lhs_name(symbol_name);
//this->def_lhs_symbol_ = symbol_name;
return;
case exprstatetype::def_1:
@ -656,50 +667,11 @@ namespace xo {
}
}
#ifdef OBSOLETE
void
exprstate::on_exprir(const exprir & ir,
exprstatestack * /*p_stack*/,
rp<Expression> * /*p_emit_expr*/)
{
constexpr bool c_debug_flag = true;
scope log(XO_DEBUG(c_debug_flag));
log && log(xtag("ir", ir));
log && log(xtag("state", *this));
switch(this->exs_type_) {
case exprstatetype::expect_toplevel_expression_sequence:
case exprstatetype::def_0:
case exprstatetype::def_1:
case exprstatetype::def_2:
case exprstatetype::def_3:
case exprstatetype::def_4:
/* NOT IMPLEMENTED */
assert(false);
return;
case exprstatetype::expect_rhs_expression:
case exprstatetype::expect_type:
case exprstatetype::expect_symbol:
/* unreachable
* (this exprstate issues pop instruction from exprstate::on_input()
*/
assert(false);
return;
case exprstatetype::invalid:
case exprstatetype::n_exprstatetype:
/* unreachable */
assert(false);
return;
}
}
#endif
void
exprstate::print(std::ostream & os) const {
os << "<exprstate"
<< xtag("type", exs_type_)
<< xtag("def_lhs_symbol", def_lhs_symbol_);
<< xtag("def_expr", def_expr_);
if (def_lhs_td_)
os << xtag("def_lhs_td", def_lhs_td_->short_name());
os << ">";