Added Lua bindings

1 files changed, 136 insertions, 0 deletions

diff --git a/Lua/lbp.c b/Lua/lbp.c
new file mode 100644
index 0000000..15d549b
--- /dev/null
+++ b/Lua/lbp.c
@@ -0,0 +1,136 @@
+/*
+* lbp.c - bp library for lua
+* API:
+*   bp.match(str, pat[, start_index]) -> nil or (match_text, start_index, match_len_in_source)
+*   bp.replace(str, pat, replacement, start_index) -> str with replacements
+*/
+
+#include <string.h>
+
+#include "lua.h"
+#include "lauxlib.h"
+
+#include "../print.h"
+#include "../files.h"
+#include "../pattern.h"
+#include "../match.h"
+
+// The C API changed from 5.1 to 5.2, so these shims help the code compile on >=5.2
+#if LUA_VERSION_NUM >= 502
+#define lua_objlen(L, i) lua_rawlen(L, i)
+#define luaL_register(L, _, R) luaL_setfuncs(L, R, 0)
+#endif
+
+static int Lmatch(lua_State *L)
+{
+    size_t textlen, patlen;
+    const char *text = luaL_checklstring(L, 1, &textlen);
+    const char *pat_text = luaL_checklstring(L, 2, &patlen);
+    lua_Integer index = luaL_optinteger(L, 3, 1);
+    if (index > (lua_Integer)strlen(text)+1)
+        return 0;
+
+    file_t *pat_file = spoof_file(NULL, "<pattern argument>", pat_text, patlen);
+    pat_t *pat = bp_pattern(pat_file, pat_file->start);
+    if (!pat) {
+        destroy_file(&pat_file);
+        luaL_error(L, "Pattern failed to compile: %s", pat_text);
+        return 0;
+    }
+
+    file_t *text_file = spoof_file(NULL, "<text argument>", text+(index-1), textlen);
+    match_t *m = NULL;
+    int ret = 0;
+    if (next_match(&m, NULL, text_file, pat, NULL, false)) {
+        char *buf = NULL;
+        size_t size = 0;
+        FILE *out = open_memstream(&buf, &size);
+        printer_t pr = {
+            .file = text_file,
+            .context_before = NO_CONTEXT,
+            .context_after = NO_CONTEXT,
+            .use_color = 0,
+            .lineformat = "",
+        };
+        print_match(out, &pr, m);
+        fflush(out);
+        lua_pushlstring(L, buf, size);
+        lua_pushinteger(L, (int)(m->start - text_file->start) + index);
+        lua_pushinteger(L, (int)(m->end - m->start));
+        fclose(out);
+        stop_matching(&m);
+        ret = 3;
+    }
+
+    destroy_file(&pat_file);
+    destroy_file(&text_file);
+    
+    return ret;
+}
+
+static int Lreplace(lua_State *L)
+{
+    size_t textlen, patlen, replen;
+    const char *text = luaL_checklstring(L, 1, &textlen);
+    const char *pat_text = luaL_checklstring(L, 2, &patlen);
+    const char *rep_text = luaL_checklstring(L, 3, &replen);
+    lua_Integer index = luaL_optinteger(L, 4, 1);
+    if (index > (lua_Integer)strlen(text)+1)
+        index = (lua_Integer)strlen(text)+1;
+
+    file_t *pat_file = spoof_file(NULL, "<pattern argument>", pat_text, patlen);
+    pat_t *pat = bp_pattern(pat_file, pat_file->start);
+    if (!pat) {
+        destroy_file(&pat_file);
+        luaL_error(L, "Pattern failed to compile: %s", pat_text);
+        return 0;
+    }
+    file_t *rep_file = spoof_file(NULL, "<replacement argument>", rep_text, replen);
+    pat = bp_replacement(rep_file, pat, rep_file->start);
+    if (!pat) {
+        destroy_file(&pat_file);
+        destroy_file(&rep_file);
+        luaL_error(L, "Replacement failed to compile: %s", rep_text);
+        return 0;
+    }
+
+    file_t *text_file = spoof_file(NULL, "<text argument>", text+(index-1), textlen);
+    char *buf = NULL;
+    size_t size = 0;
+    FILE *out = open_memstream(&buf, &size);
+    printer_t pr = {
+        .file = text_file,
+        .context_before = ALL_CONTEXT,
+        .context_after = ALL_CONTEXT,
+        .use_color = 0,
+        .lineformat = "",
+    };
+    int replacements = 0;
+    for (match_t *m = NULL; next_match(&m, NULL, text_file, pat, NULL, false); ) {
+        print_match(out, &pr, m);
+        ++replacements;
+    }
+    print_match(out, &pr, NULL);
+    fflush(out);
+    lua_pushlstring(L, buf, size);
+    lua_pushinteger(L, replacements);
+    fclose(out);
+
+    destroy_file(&pat_file);
+    destroy_file(&rep_file);
+    destroy_file(&text_file);
+    
+    return 2;
+}
+
+LUALIB_API int luaopen_bp(lua_State *L)
+{
+    lua_createtable(L, 0, 2);
+    lua_pushcfunction(L, Lmatch);
+    lua_setfield(L, -2, "match");
+    lua_pushcfunction(L, Lreplace);
+    lua_setfield(L, -2, "replace");
+    // lua_pushcfunction(L, Leach);
+    // lua_setfield(L, -1, "each");
+    return 1;
+}