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Merged
sentomk merged 1 commit into from
Jul 31, 2026
Merged

feat(guard): unify placeholder syntax #43

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2 changes: 2 additions & 0 deletions CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -115,7 +115,9 @@ PTN_JOIN_HEADERS(PTN_HEADERS
include/ptn/pattern/structural.hpp
include/ptn/pattern/combinator.hpp
include/ptn/pattern/pred.hpp
include/ptn/pattern/negation.hpp
include/ptn/pattern/modifiers/guard.hpp
include/ptn/pattern/modifiers/placeholder.hpp
include/ptn/pattern/modifiers/fwd.h
)

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6 changes: 3 additions & 3 deletions README.md
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Expand Up @@ -57,7 +57,7 @@ int classify(int x) {

- Literal, structural, and `std::variant` matching in one DSL.
- Explicit binding through `$` and `$(...)`.
- Declarative guards via `PTN_LET`, `PTN_WHERE`, `_0`, `arg<N>`, `rng(...)`, and callables.
- Declarative guards via `_`, `PTN_BIND`, `rng(...)`, and callables.
- No RTTI, no virtual dispatch, no heap allocation.
- Static literal and variant dispatch lowering for hot paths.

Expand All @@ -70,8 +70,8 @@ using namespace ptn;

const char *bucket(int x) {
return match(x) | on(
$[PTN_LET(value, value < 0)] >> "negative",
$[PTN_LET(value, value < 10)] >> "small",
$[_ < 0] >> "negative",
$[_ < 10] >> "small",
_ >> "large"
);
}
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8 changes: 4 additions & 4 deletions bench/bench_scale.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -216,7 +216,7 @@ namespace {
is<EvtDisconnect>() >> 2,
is<EvtMessage>() >> 3,
is<EvtAck>() >> 4,
__ >> 0);
_ >> 0);
}

int scaleN_ptn8(const Evt8 &e) {
Expand All @@ -231,7 +231,7 @@ namespace {
is<EvtPong>() >> 6,
is<EvtError>() >> 7,
is<EvtTimeout>() >> 8,
__ >> 0);
_ >> 0);
}

int scaleN_ptn16(const Evt16 &e) {
Expand All @@ -254,7 +254,7 @@ namespace {
is<EvtInput>() >> 14,
is<EvtFocus>() >> 15,
is<EvtRender>() >> 16,
__ >> 0);
_ >> 0);
}

int scaleN_ptn32(const Evt32 &e) {
Expand Down Expand Up @@ -293,7 +293,7 @@ namespace {
is<EvtCompress>() >> 30,
is<EvtCache>() >> 31,
is<EvtRetry>() >> 32,
__ >> 0);
_ >> 0);
}

// ---- StdVisit dispatchers ----
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52 changes: 26 additions & 26 deletions bench/bench_suite.cpp
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Expand Up @@ -194,21 +194,21 @@ namespace {
using ptn::pat::is;

return match(v)
| on(is<int>() >> 1, is<std::string>() >> 2, __ >> 0);
| on(is<int>() >> 1, is<std::string>() >> 2, _ >> 0);
}

static int patternia_pipe_variant_route(const V &v) {
using namespace ptn;
using ptn::pat::is;

return match(v)
| on(is<int>() >> 1, is<std::string>() >> 2, __ >> 0);
| on(is<int>() >> 1, is<std::string>() >> 2, _ >> 0);
}

static int patternia_pipe_variant_alt_route(const V &v) {
using namespace ptn;

return match(v) | on(alt<0>() >> 1, alt<1>() >> 2, __ >> 0);
return match(v) | on(alt<0>() >> 1, alt<1>() >> 2, _ >> 0);
}

static int patternia_pipe_variant_alt_32_route(const VAlt32 &v) {
Expand Down Expand Up @@ -247,7 +247,7 @@ namespace {
alt<29>() >> 30,
alt<30>() >> 31,
alt<31>() >> 32,
__ >> 0);
_ >> 0);
}

static int
Expand Down Expand Up @@ -286,7 +286,7 @@ namespace {
alt<29>() >> 30,
alt<30>() >> 31,
alt<31>() >> 32,
__ >> 0);
_ >> 0);

return match(v) | cases;
}
Expand Down Expand Up @@ -407,11 +407,11 @@ namespace {
};

return match(v)
| on($(is<int>())[_0 > 100] >> 10,
| on($(is<int>())[_ > 100] >> 10,
is<int>() >> 1,
$(is<std::string>())[long_string] >> 20,
is<std::string>() >> 2,
__ >> 0);
_ >> 0);
}

static int patternia_pipe_variant_guarded_route(const V &v) {
Expand All @@ -421,11 +421,11 @@ namespace {
};

return match(v)
| on($(is<int>())[_0 > 100] >> 10,
| on($(is<int>())[_ > 100] >> 10,
is<int>() >> 1,
$(is<std::string>())[long_string] >> 20,
is<std::string>() >> 2,
__ >> 0);
_ >> 0);
}

static int std_visit_variant_guarded_route(const V &v) {
Expand Down Expand Up @@ -510,7 +510,7 @@ namespace {
is<ProtoError>() >> 3,
$(is<ProtoControl>())[control_ack] >> 44,
is<ProtoControl>() >> 4,
__ >> 0);
_ >> 0);
}

static int patternia_pipe_protocol_router(const ProtocolMsg &msg) {
Expand All @@ -533,7 +533,7 @@ namespace {
is<ProtoError>() >> 3,
$(is<ProtoControl>())[control_ack] >> 44,
is<ProtoControl>() >> 4,
__ >> 0);
_ >> 0);
}

static int if_else_protocol_router(const ProtocolMsg &msg) {
Expand Down Expand Up @@ -634,7 +634,7 @@ namespace {
is<CmdDel>() >> 300,
$(is<CmdScan>())[wide_scan] >> 401,
is<CmdScan>() >> 400,
__ >> 0);
_ >> 0);
}

static int patternia_pipe_command_parser(const CommandMsg &msg) {
Expand All @@ -657,7 +657,7 @@ namespace {
is<CmdDel>() >> 300,
$(is<CmdScan>())[wide_scan] >> 401,
is<CmdScan>() >> 400,
__ >> 0);
_ >> 0);
}

static int if_else_command_parser(const CommandMsg &msg) {
Expand Down Expand Up @@ -750,7 +750,7 @@ namespace {
lit(6) >> 6,
lit(7) >> 7,
lit(8) >> 8,
__ >> 0);
_ >> 0);
}

static int patternia_literal_match_route(int x) {
Expand All @@ -765,7 +765,7 @@ namespace {
lit(6) >> 6,
lit(7) >> 7,
lit(8) >> 8,
__ >> 0);
_ >> 0);
}

static int if_else_literal_match_route(int x) {
Expand Down Expand Up @@ -877,7 +877,7 @@ namespace {

static int patternia_pipe_literal_match_16_route(int x) {
using namespace ptn;
return match(x) | on(PTN_RT_LIT_BLOCK_16(1), __ >> 0);
return match(x) | on(PTN_RT_LIT_BLOCK_16(1), _ >> 0);
}

static int if_else_literal_match_16_route(int x) {
Expand All @@ -900,7 +900,7 @@ namespace {
return match(x)
| on(PTN_RT_LIT_BLOCK_16(1),
PTN_RT_LIT_BLOCK_16(17),
__ >> 0);
_ >> 0);
}

static int if_else_literal_match_32_route(int x) {
Expand All @@ -927,7 +927,7 @@ namespace {
PTN_RT_LIT_BLOCK_16(17),
PTN_RT_LIT_BLOCK_16(33),
PTN_RT_LIT_BLOCK_16(49),
__ >> 0);
_ >> 0);
}

static int if_else_literal_match_64_route(int x) {
Expand Down Expand Up @@ -971,7 +971,7 @@ namespace {
ptn::lit(84) >> 84,
ptn::lit(91) >> 91,
ptn::lit(98) >> 98,
__ >> 0);
_ >> 0);
}

static int if_else_literal_match_rdense_route(int x) {
Expand Down Expand Up @@ -1090,7 +1090,7 @@ namespace {
PTN_LIT_BLOCK_16(81),
PTN_LIT_BLOCK_16(97),
PTN_LIT_BLOCK_16(113),
__ >> 0);
_ >> 0);

return match(x) | cases;
}
Expand All @@ -1107,7 +1107,7 @@ namespace {
PTN_LIT_BLOCK_16(81),
PTN_LIT_BLOCK_16(97),
PTN_LIT_BLOCK_16(113),
__ >> 0);
_ >> 0);
}

static int patternia_pipe_literal_match_128_on_macro_route(int x) {
Expand All @@ -1122,7 +1122,7 @@ namespace {
PTN_LIT_BLOCK_16(81),
PTN_LIT_BLOCK_16(97),
PTN_LIT_BLOCK_16(113),
__ >> 0);
_ >> 0);
}

static int switch_literal_match_128_route(int x) {
Expand Down Expand Up @@ -1242,7 +1242,7 @@ namespace {
[is_valid_data_packet]
>> 2,
$(has<&Packet::type>)[is_error_packet] >> 3,
__ >> 0);
_ >> 0);
}

static int patternia_pipe_packet_route(const Packet &pkt) {
Expand Down Expand Up @@ -1272,7 +1272,7 @@ namespace {
[is_valid_data_packet]
>> 2,
$(has<&Packet::type>)[is_error_packet] >> 3,
__ >> 0);
_ >> 0);
}

static int switch_packet_route(const Packet &pkt) {
Expand Down Expand Up @@ -1335,7 +1335,7 @@ namespace {
$(has<&Packet::type,
&Packet::payload>)[is_error_packet]
>> 3,
__ >> 0);
_ >> 0);
}

static int
Expand Down Expand Up @@ -1375,7 +1375,7 @@ namespace {
$(has<&Packet::type,
&Packet::payload>)[is_error_packet]
>> 3,
__ >> 0);
_ >> 0);
}

static int switch_packet_heavy_bind_route(const Packet &pkt) {
Expand Down
2 changes: 1 addition & 1 deletion bench/compile-time/CMakeLists.txt
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Expand Up @@ -26,7 +26,7 @@ function(_ptn_ct_add_lit_tu N)
foreach(_i RANGE 0 ${_last} 1)
string(APPEND _cases " ptn::lit(${_i}) >> ${_i},\n")
endforeach()
string(APPEND _cases " __ >> 0);\n")
string(APPEND _cases " _ >> 0);\n")
file(APPEND "${_tufile}" "${_cases}")
file(APPEND "${_tufile}" "}\n\n")

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4 changes: 2 additions & 2 deletions bench/compile-time/ct_bench_compound.cpp
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Expand Up @@ -14,13 +14,13 @@ namespace {
ptn::lit(2) >> 2,
ptn::lit(3) >> 3,
ptn::lit(4) >> 4,
__ >> 0);
_ >> 0);
}

int ct_combo_variant(const VariantT &v) {
using namespace ptn;
return match(v)
| on(is<int>() >> 100, is<std::string>() >> 200, __ >> 0);
| on(is<int>() >> 100, is<std::string>() >> 200, _ >> 0);
}

int (*volatile sink_lit)(int) = ct_combo_lit;
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2 changes: 1 addition & 1 deletion bench/compile-time/ct_bench_lit_128.cpp
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Expand Up @@ -134,7 +134,7 @@ constexpr int ct_lit_128(int v) noexcept {
ptn::lit(125) >> 125,
ptn::lit(126) >> 126,
ptn::lit(127) >> 127,
__ >> 0);
_ >> 0);
}

static_assert(ct_lit_128(0) == 0, "");
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2 changes: 1 addition & 1 deletion bench/compile-time/ct_bench_lit_16.cpp
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Expand Up @@ -22,7 +22,7 @@ constexpr int ct_lit_16(int v) noexcept {
ptn::lit(13) >> 13,
ptn::lit(14) >> 14,
ptn::lit(15) >> 15,
__ >> 0);
_ >> 0);
}

static_assert(ct_lit_16(0) == 0, "");
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2 changes: 1 addition & 1 deletion bench/compile-time/ct_bench_lit_32.cpp
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Expand Up @@ -38,7 +38,7 @@ constexpr int ct_lit_32(int v) noexcept {
ptn::lit(29) >> 29,
ptn::lit(30) >> 30,
ptn::lit(31) >> 31,
__ >> 0);
_ >> 0);
}

static_assert(ct_lit_32(0) == 0, "");
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2 changes: 1 addition & 1 deletion bench/compile-time/ct_bench_lit_64.cpp
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Expand Up @@ -70,7 +70,7 @@ constexpr int ct_lit_64(int v) noexcept {
ptn::lit(61) >> 61,
ptn::lit(62) >> 62,
ptn::lit(63) >> 63,
__ >> 0);
_ >> 0);
}

static_assert(ct_lit_64(0) == 0, "");
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2 changes: 1 addition & 1 deletion bench/compile-time/ct_bench_lit_8.cpp
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Expand Up @@ -14,7 +14,7 @@ constexpr int ct_lit_8(int v) noexcept {
ptn::lit(5) >> 5,
ptn::lit(6) >> 6,
ptn::lit(7) >> 7,
__ >> 0);
_ >> 0);
}

static_assert(ct_lit_8(0) == 0, "");
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2 changes: 1 addition & 1 deletion bench/compile-time/ct_bench_lit_rdense.cpp
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Expand Up @@ -19,7 +19,7 @@ namespace {
ptn::lit(84) >> 84,
ptn::lit(91) >> 91,
ptn::lit(98) >> 98,
__ >> 0);
_ >> 0);
}

static_assert(ct_lit_rdense(0) == 0, "");
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2 changes: 1 addition & 1 deletion bench/compile-time/ct_bench_variant_32.cpp
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Expand Up @@ -77,7 +77,7 @@ namespace {
alt<29>() >> 30,
alt<30>() >> 31,
alt<31>() >> 32,
__ >> 0);
_ >> 0);
}

int (*volatile sink)(const VAlt32 &) = ct_var_alt_route;
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