76 lines
2.3 KiB
C++
76 lines
2.3 KiB
C++
/** @file DExprSeqState.hpp
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*
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* @author Roland Conybeare, Jan 2026
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**/
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#pragma once
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#include "ParserStateMachine.hpp"
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#include "SyntaxStateMachine.hpp"
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#include "syntaxstatetype.hpp"
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#include <xo/facet/obj.hpp>
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namespace xo {
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namespace scm {
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enum class exprseqtype {
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/** toplevel interactive sequence.
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* allows: rvalue expressions
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**/
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toplevel_interactive,
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/** toplevel non-interactive sequence.
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* allows:
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**/
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toplevel_batch,
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/** counts number of valid enums **/
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N
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};
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/** @class DExprSeqState
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* @brief state machine for parsing a sequence of expression
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*
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* Similar to exprseq_xs in xo-expresion
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**/
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class DExprSeqState {
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public:
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using AAllocator = xo::mm::AAllocator;
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public:
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explicit DExprSeqState(exprseqtype ty);
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/** start interactive top-level session **/
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static void establish_interactive(obj<AAllocator> mm,
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ParserStateMachine * p_psm);
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/** start non-interactive top-level session **/
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static void establish_batch(obj<AAllocator> mm,
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ParserStateMachine * p_psm);
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public:
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/** @defgroup scm-exprseq-ssm-facet syntaxstatemachine facet methods **/
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///@{
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/** identifies the ssm implemented here **/
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syntaxstatetype ssm_type() const noexcept;
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/** text describing expected/allowed input to this ssm in current state.
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* Intended to drive error mesages
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**/
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std::string_view get_expect_str() const noexcept;
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/** update state for this syntax on incoming token @p tk,
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* overall parser state in @p p_psm
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**/
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void on_if_token(const Token & tk, ParserStateMachine * p_psm);
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///@}
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private:
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/** sequence type. accept rvalue expressions when
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* this is toplevel_interactive.
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* Always accept definitions and declarations.
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**/
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exprseqtype seqtype_;
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};
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} /*namespace scm*/
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} /*namespace xo*/
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/* end DExprSeqState.hpp */
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