1 files changed, 128 insertions, 0 deletions
diff --git a/src/stdlib/simpleparse.c b/src/stdlib/simpleparse.c
new file mode 100644
index 00000000..1ee64036
--- /dev/null
+++ b/src/stdlib/simpleparse.c
@@ -0,0 +1,128 @@
+// A simple text parsing primitive:
+//     const char *line = "foo.txt:15";
+//     const char *filename; int line;
+//     if (strparse(line, &filename, ":", &line)) { success...}
+// or:
+//     FILE *f = ...;
+//     if (fparse(f, &filename, ":", &line)) { success... }
+
+#include <ctype.h>
+#include <gc.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "simpleparse.h"
+#include "util.h"
+
+static bool _match_word(const char **str, const char *target) {
+    size_t len = strlen(target);
+    if (strncasecmp(*str, target, len) == 0 && !isalnum((*str)[len]) && (*str)[len] != '_') {
+        *str += len;
+        return true;
+    }
+    return false;
+}
+
+public const char *simpleparse(const char *str, int n, parse_type_e types[n], void *destinations[n])
+{
+    for (int i = 0; i < n; i++) {
+        switch (types[i]) {
+        case PARSE_SOME_OF: {
+            if (destinations[i]) str += strspn(str, (char*)destinations[i]);
+            break;
+        }
+        case PARSE_LITERAL: {
+            const char *target = (const char*)destinations[i];
+            if (target) {
+                if (strncmp(str, target, strlen(target)) != 0)
+                    return str;
+                str += strlen(target);
+            }
+            break;
+        }
+        case PARSE_STRING: {
+            size_t len;
+            static const char matching_pair[256] = {[(int)'(']=')', [(int)'{']='}', [(int)'[']=']',
+                [(int)'"']='"', [(int)'\'']='\'', [(int)'`']='`', [(int)'<']='>'};
+            if (i > 0 && i + 1 < n && types[i-1] == PARSE_LITERAL && types[i+1] == PARSE_LITERAL
+                && destinations[i-1] && destinations[i+1]
+                && strlen((char*)destinations[i-1]) == 1 && strlen((char*)destinations[i+1]) == 1
+                && *(char*)destinations[i+1] == matching_pair[(int)*(char*)destinations[i-1]]) {
+                len = 0;
+                char special_characters[4] = {'\\', *(char*)destinations[i-1], *(char*)destinations[i+1], 0};
+                for (int depth = 1; depth > 0; ) {
+                    len += strcspn(str + len, special_characters);
+                    if (str[len] == '\0') {
+                        return str;
+                    } else if (str[len] == '\\'
+                             && (special_characters[1] == '"' || special_characters[1] == '\'' || special_characters[1] == '`')) {
+                        if (str[len+1] == '\0') return str;
+                        len += 2; 
+                    } else if (str[len] == special_characters[2]) { // Check for closing quotes before opening quotes
+                        depth -= 1;
+                        if (depth > 0) len += 1;
+                    } else if (str[len] == special_characters[1]) {
+                        depth += 1;
+                        if (depth > 999999) return str;
+                        len += 1;
+                    }
+                }
+            } else if (i + 1 < n && types[i+1] == PARSE_LITERAL) {
+                const char *terminator = (const char*)destinations[i+1];
+                if (terminator) {
+                    const char *end = strstr(str, terminator);
+                    if (!end) return str;
+                    len = (size_t)((ptrdiff_t)end - (ptrdiff_t)str);
+                } else {
+                    len = strlen(str);
+                }
+            } else if (i + 1 < n && types[i+1] == PARSE_SOME_OF) {
+                len = destinations[i+1] ? strcspn(str, (char*)destinations[i+1]) : strlen(str);;
+            } else {
+                len = strlen(str);
+            }
+            if (destinations[i]) {
+                char *matched = GC_MALLOC_ATOMIC(len+1);
+                memcpy(matched, str, len);
+                matched[len] = '\0';
+                *(const char**)destinations[i] = matched;
+            }
+            str += len;
+            break;
+        }
+        case PARSE_DOUBLE: {
+            char *end = NULL;
+            double val = strtod(str, &end);
+            if (end == str) return str;
+            if (destinations[i]) *(double*)destinations[i] = val;
+            str = end;
+            break;
+        }
+        case PARSE_LONG: {
+            char *end = NULL;
+            long val = strtol(str, &end, 10);
+            if (end == str) return str;
+            if (destinations[i]) *(long*)destinations[i] = val;
+            str = end;
+            break;
+        }
+        case PARSE_BOOL: {
+            if (_match_word(&str, "true") || _match_word(&str, "yes") || _match_word(&str, "on") || _match_word(&str, "1")) {
+                if (destinations[i]) *(bool*)destinations[i] = true;
+            } else if (_match_word(&str, "false") || _match_word(&str, "no") || _match_word(&str, "off") || _match_word(&str, "0")) {
+                if (destinations[i]) *(bool*)destinations[i] = false;
+            } else {
+                return str;
+            }
+            break;
+        }
+        default: break;
+        }
+    }
+    return NULL;
+}
+
+// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0