Changed how tags work, changed Lua API for handling match captures

6 files changed, 51 insertions, 44 deletions

diff --git a/Lua/lbp.c b/Lua/lbp.c
index 5e94890..c1c3f61 100644
--- a/Lua/lbp.c
+++ b/Lua/lbp.c
@@ -80,39 +80,45 @@ static void push_matchstring(lua_State *L, match_t *m)
     fclose(out);
 }
 
-static void set_capture_fields(lua_State *L, match_t *m, int *n, const char *start)
+static match_t *get_first_capture(match_t *m)
 {
     if (m->pat->type == BP_TAGGED) {
-        push_match(L, m, start);
-        lua_seti(L, -2, (*n)++);
-    } else if (m->pat->type == BP_CAPTURE) {
+        return m;
+    } else if (m->pat->type == BP_CAPTURE && !m->pat->args.capture.name) {
+        return m;
+    } else if (m->children) {
+        for (int i = 0; m->children[i]; i++) {
+            match_t *cap = get_first_capture(m->children[i]);
+            if (cap) return cap;
+        }
+    }
+    return NULL;
+}
+
+static void set_capture_fields(lua_State *L, match_t *m, int *n, const char *start)
+{
+    if (m->pat->type == BP_CAPTURE) {
+        match_t *cap = get_first_capture(m->children[0]);
+        if (!cap) cap = m->children[0];
         if (m->pat->args.capture.namelen > 0) {
             lua_pushlstring(L, m->pat->args.capture.name, m->pat->args.capture.namelen);
-            push_match(L, m->children[0], start);
+            push_match(L, cap, start);
             lua_settable(L, -3);
         } else {
-            push_match(L, m->children[0], start);
+            push_match(L, cap, start);
             lua_seti(L, -2, (*n)++);
         }
+    } else if (m->pat->type == BP_TAGGED) {
+        push_match(L, m, start);
+        lua_seti(L, -2, (*n)++);
     } else if (m->children) {
-        for (int i = 0; m->children[i]; i++) {
-            if (m->children[i]->pat->type == BP_TAGGED) {
-                push_match(L, m->children[i], start);
-                lua_seti(L, -2, (*n)++);
-            } else {
-                set_capture_fields(L, m->children[i], n, start);
-            }
-        }
+        for (int i = 0; m->children[i]; i++)
+            set_capture_fields(L, m->children[i], n, start);
     }
 }
 
 static void push_match(lua_State *L, match_t *m, const char *start)
 {
-    // Given tag::id,
-    // Case 1: (@id _ tag _ @id)  -> {[0]="foo baz qux", 1={[0]="foo", __tag="tag"}, 2={[0]="qux"}}
-    // Case 2: (@id _ @tag _ @id) -> {[0]="foo baz qux", 1={[0]="foo"}, 2={[0]="baz", 1={[0]="baz", __tag="tag"}}, 3={[0]="qux"}}
-    // Case 3: (@id @(_tag_) @id) -> {[0]="foo baz qux", 1={[0]="foo"}, 2={[0]=" baz ", 1={[0]="baz", __tag="tag"}}, 3={[0]="qux"}}
-    // Case 4: (@first=id _ @second=tag _ @third=id) -> {[0]="foo baz qux", first={[0]="foo"}, second={[0]="baz", 1={[0]="baz", __tag="tag"}}, third={[0]="qux"}}
     lua_createtable(L, 1, 2);
     lua_pushlightuserdata(L, (void*)&MATCH_METATABLE);
     lua_gettable(L, LUA_REGISTRYINDEX);
diff --git a/bp.1 b/bp.1
index 635f7fd..3e585a4 100644
--- a/bp.1
+++ b/bp.1
@@ -355,13 +355,13 @@ not contain the word \f[B]\[lq]IGNORE\[rq]\f[R])
 \f[I]name\f[R]\f[B]:\f[R] \f[I]pat\f[R]
 Define \f[I]name\f[R] to mean \f[I]pat\f[R] (pattern definition)
 .TP
-\f[B]:\f[R]\f[I]name\f[R] \f[I]pat\f[R]
+\f[B]\[at]:\f[R]\f[I]name\f[R] \f[B]=\f[R] \f[I]pat\f[R]
 Match \f[I]pat\f[R] and tag it with the given name as metadata.
 .TP
 \f[I]name\f[R]\f[B]::\f[R] \f[I]pat\f[R]
-Syntactic sugar for \f[I]name\f[R]\f[B]::\f[R] \f[B]:\f[R]\f[I]name\f[R]
-\f[I]pat\f[R] (define a pattern that also attaches a metadata tag of the
-same name)
+Syntactic sugar for \f[I]name\f[R]\f[B]:\f[R]
+\f[B]\[at]:\f[R]\f[I]name\f[R]\f[B]=\f[R]\f[I]pat\f[R] (define a pattern
+that also attaches a metadata tag of the same name)
 .TP
 \f[B]#\f[R] \f[I]comment\f[R]
 A line comment
diff --git a/bp.1.md b/bp.1.md
index 986f94a..d91e9ac 100644
--- a/bp.1.md
+++ b/bp.1.md
@@ -291,11 +291,11 @@ contain the word **"IGNORE"**)
 *name*`:` *pat*
 : Define *name* to mean *pat* (pattern definition)
 
-`:`*name* *pat*
+`@:`*name* `=` *pat*
 : Match *pat* and tag it with the given name as metadata.
 
 *name*`::` *pat*
-: Syntactic sugar for *name*`::` `:`*name* *pat* (define a pattern that also
+: Syntactic sugar for *name*`:` `@:`*name*`=`*pat* (define a pattern that also
 attaches a metadata tag of the same name)
 
 `#` *comment*
diff --git a/grammars/builtins.bp b/grammars/builtins.bp
index 16df6e6..b846f3b 100644
--- a/grammars/builtins.bp
+++ b/grammars/builtins.bp
@@ -14,7 +14,7 @@ string-escape: `\ (`x 2 Hex / 1-3 `0-7 / `u 1-4 Hex / .)
 id: \I *\i
 var: \I *\i
 keyword: !"" # No keywords defined by default
-word: | +\i
+word: \b +\i
 HEX: `0-9,A-F
 Hex: `0-9,a-f,A-F
 hex: `0-9,a-f
diff --git a/pattern.c b/pattern.c
index 83f2b29..9620c5d 100644
--- a/pattern.c
+++ b/pattern.c
@@ -475,6 +475,24 @@ static pat_t *_bp_simplepattern(const char *str, const char *end, bool inside_st
     }
     // Capture
     case '@': {
+        if (matchchar(&str, ':', false, end)) { // Tagged capture @:Foo=pat
+            const char *name = str;
+            str = after_name(name, end);
+            if (str <= name)
+                parse_err(start, str, "There should be an identifier after this '@:'");
+            size_t namelen = (size_t)(str - name);
+            pat_t *p = NULL;
+            if (matchchar(&str, '=', false, end)) {
+                p = bp_simplepattern(str, end);
+                if (p) str = p->end;
+            }
+            pat_t *tagged = new_pat(BP_TAGGED, start, str, p ? p->min_matchlen : 0, p ? p->max_matchlen : 0);
+            tagged->args.capture.capture_pat = p;
+            tagged->args.capture.name = name;
+            tagged->args.capture.namelen = namelen;
+            return tagged;
+        }
+
         const char *name = NULL;
         size_t namelen = 0;
         const char *a = after_name(str, end);
@@ -513,23 +531,6 @@ static pat_t *_bp_simplepattern(const char *str, const char *end, bool inside_st
             return new_pat(BP_END_OF_FILE, start, ++str, 0, 0);
         return new_pat(BP_END_OF_LINE, start, str, 0, 0);
     }
-    // Tagged pattern :Tag:pat...
-    case ':': {
-        const char *name = str;
-        str = after_name(name, end);
-        if (str == name)
-            parse_err(start, str, "There should be an identifier after this ':'");
-        size_t namelen = (size_t)(str - name);
-        (void)matchchar(&str, ':', false, end); // Optional second colon for :Tag:foo instead of :Tag(foo)
-
-        pat_t *p = bp_simplepattern(str, end);
-        if (p) str = p->end;
-        pat_t *tagged = new_pat(BP_TAGGED, start, str, p ? p->min_matchlen : 0, p ? p->max_matchlen : 0);
-        tagged->args.capture.capture_pat = p;
-        tagged->args.capture.name = start;
-        tagged->args.capture.namelen = namelen;
-        return tagged;
-    }
     default: {
         pat_t *def = _bp_definition(start, end);
         if (def) return def;
diff --git a/utils.c b/utils.c
index d683492..edf0176 100644
--- a/utils.c
+++ b/utils.c
@@ -43,7 +43,7 @@ const char *after_spaces(const char *str, bool skip_nl, const char *end)
 //
 const char *after_name(const char *str, const char *end)
 {
-    if (str >= end) return NULL;
+    if (str >= end) return end;
     if (*str == '|') return &str[1];
     if (*str == '^' || *str == '_' || *str == '$') {
         return (&str[1] < end && str[1] == *str) ? &str[2] : &str[1];