Change the output format to be more readable in order to understand the output of the parser, I think I will turn this output into optional debug output at some point but it is useful for now in development.

md2teach/main.c

@@ -50,7 +50,7 @@ static void debugLogHook(const char * message, void * userdata);
 
 MD_PARSER parser = {
     0, // abi_version
-    0, // flags
+    MD_FLAG_NOHTMLBLOCKS | MD_FLAG_NOHTMLSPANS, // flags
     enterBlockHook,
     leaveBlockHook,
     enterSpanHook,
@@ -60,42 +60,231 @@ MD_PARSER parser = {
     NULL // syntax
 };
 
+void * lowestStackSeen;
+char * commandName;
+int indentLevel = 0;
+
 
 // Implementation
 
 static int enterBlockHook(MD_BLOCKTYPE type, void * detail, void * userdata)
 {
-    printf("Enter Block: type = %d, detail = %p\n", (int)type, detail);
+    if ((detail != NULL) &&
+        (detail < lowestStackSeen))
+        lowestStackSeen = detail;
+    
+    switch (type) {
+        case MD_BLOCK_DOC:
+            printf("%*sDOC {\n", indentLevel, "");
+            break;
+            
+        case MD_BLOCK_QUOTE:
+            printf("%*sQUOTE {\n", indentLevel, "");
+            break;
+            
+        case MD_BLOCK_UL: {
+            MD_BLOCK_UL_DETAIL * ulDetail = (MD_BLOCK_UL_DETAIL *)detail;
+            printf("%*sUL (is_tight=%d, mark=%c) {\n", indentLevel, "", ulDetail->is_tight, ulDetail->mark);
+            break;
+        }
+            
+        case MD_BLOCK_OL: {
+            MD_BLOCK_OL_DETAIL * olDetail = (MD_BLOCK_OL_DETAIL *)detail;
+            printf("%*sOL (start=%u, is_tight=%d, mark_delimiter=%c) {\n", indentLevel, "", olDetail->start, olDetail->is_tight, olDetail->mark_delimiter);
+            break;
+        }
+            
+        case MD_BLOCK_LI:
+            printf("%*sLI {\n", indentLevel, "");
+            break;
+            
+        case MD_BLOCK_HR:
+            printf("%*sHR {\n", indentLevel, "");
+            break;
+            
+        case MD_BLOCK_H: {
+            MD_BLOCK_H_DETAIL * hDetail = (MD_BLOCK_H_DETAIL *)detail;
+            printf("%*sH (level=%u) {\n", indentLevel, "", hDetail->level);
+            break;
+        }
+            
+        case MD_BLOCK_CODE: {
+            MD_BLOCK_CODE_DETAIL * codeDetail = (MD_BLOCK_CODE_DETAIL *)detail;
+            printf("%*sCODE ", indentLevel, "");
+            if (codeDetail->fence_char != '\0') {
+                printf("(fence_char=%c) ", codeDetail->fence_char);
+            }
+            printf("{\n");
+            break;
+        }
+            
+        case MD_BLOCK_P:
+            printf("%*sP {\n", indentLevel, "");
+            break;
+            
+        default:
+            fprintf(stderr, "%s: Invalid block type (%d)\n", commandName, (int)type);
+            return 1;
+            break;
+    }
+    
+    indentLevel+=2;
     return 0;
 }
 
 
 static int leaveBlockHook(MD_BLOCKTYPE type, void * detail, void * userdata)
 {
-    printf("Leave Block: type = %d, detail = %p\n", (int)type, detail);
+    if ((detail != NULL) &&
+        (detail < lowestStackSeen))
+        lowestStackSeen = detail;
+    
+    switch (type) {
+        case MD_BLOCK_DOC:
+            break;
+            
+        case MD_BLOCK_QUOTE:
+            break;
+            
+        case MD_BLOCK_UL:
+            break;
+            
+        case MD_BLOCK_OL:
+            break;
+            
+        case MD_BLOCK_LI:
+            break;
+            
+        case MD_BLOCK_HR:
+            break;
+            
+        case MD_BLOCK_H:
+            break;
+            
+        case MD_BLOCK_CODE:
+            break;
+            
+        case MD_BLOCK_P:
+            break;
+            
+        default:
+            fprintf(stderr, "%s: Invalid block type (%d)\n", commandName, (int)type);
+            return 1;
+            break;
+    }
+    
+    indentLevel-=2;
+    printf("%*s}\n", indentLevel, "");
+    
     return 0;
 }
 
 
 static int enterSpanHook(MD_SPANTYPE type, void * detail, void * userdata)
 {
-    printf("Enter Span: type = %d, detail = %p\n", (int)type, detail);
+    if ((detail != NULL) &&
+        (detail < lowestStackSeen))
+        lowestStackSeen = detail;
+    
+    switch (type) {
+        case MD_SPAN_EM:
+            printf("%*sEM {\n", indentLevel, "");
+            break;
+            
+        case MD_SPAN_STRONG:
+            printf("%*sSTRONG {\n", indentLevel, "");
+            break;
+            
+        case MD_SPAN_A:
+            printf("%*sA {\n", indentLevel, "");
+            break;
+            
+        case MD_SPAN_IMG:
+            printf("%*sIMG {\n", indentLevel, "");
+            break;
+            
+        case MD_SPAN_CODE:
+            printf("%*sCODE {\n", indentLevel, "");
+            break;
+            
+        default:
+            fprintf(stderr, "%s: Invalid span type (%d)\n", commandName, (int)type);
+            return 1;
+            break;
+    }
+    
+    indentLevel+=2;
     return 0;
 }
 
 
 static int leaveSpanHook(MD_SPANTYPE type, void * detail, void * userdata)
 {
-    printf("Leave Span: type = %d, detail = %p\n", (int)type, detail);
+    if ((detail != NULL) &&
+        (detail < lowestStackSeen))
+        lowestStackSeen = detail;
+    
+    switch (type) {
+        case MD_SPAN_EM:
+            break;
+            
+        case MD_SPAN_STRONG:
+            break;
+            
+        case MD_SPAN_A:
+            break;
+            
+        case MD_SPAN_IMG:
+            break;
+            
+        case MD_SPAN_CODE:
+            break;
+            
+        default:
+            fprintf(stderr, "%s: Invalid span type (%d)\n", commandName, (int)type);
+            return 1;
+            break;
+    }
+    
+    indentLevel-=2;
+    printf("%*s}\n", indentLevel, "");
+    
     return 0;
 }
 
 
 static int textHook(MD_TEXTTYPE type, const MD_CHAR * text, MD_SIZE size, void * userdata)
 {
-    printf("Text: type = %d, size=%lu, text=", (int)type, size);
+    switch (type) {
+        case MD_TEXT_NORMAL:
+            printf("%*sText: \"", indentLevel, "");
+            break;
+        
+        case MD_TEXT_NULLCHAR:
+            fprintf(stderr, "%s: Null character encountered on input\n", commandName);
+            return 1;
+            
+        case MD_TEXT_BR:
+        case MD_TEXT_SOFTBR:
+            return 0;
+            
+        case MD_TEXT_ENTITY:
+            printf("%*sEntity: \"", indentLevel, "");
+            break;
+            
+        case MD_TEXT_CODE:
+            printf("%*sCode: \"", indentLevel, "");
+            break;
+            
+        default:
+            fprintf(stderr, "%s: Invalid text type (%d)\n", commandName, (int)type);
+            return 1;
+            break;
+    }
+    
     fwrite(text, sizeof(MD_CHAR), size, stdout);
-    putchar('\n');
+    printf("\"\n");
+    
     return 0;
 }
 
@@ -108,9 +297,7 @@ static void debugLogHook(const char * message, void * userdata)
 
 int main(int argc, char * argv[])
 {
-    static int result;
+    int result;
-    
-    static char * commandName;
     
     static char * inputFileName;
     static FILE * inputFile;
@@ -119,7 +306,7 @@ int main(int argc, char * argv[])
     
     static char * outputFileName;
     
-    printf("Stack start: %p\n", &result);
+    lowestStackSeen = &result;
     
     if (argc != 3) {
         fprintf(stderr, "USAGE: %s inputfile outputfile\n", argv[0]);
@@ -172,6 +359,7 @@ int main(int argc, char * argv[])
     
     result = md_parse(inputBuffer, inputFileLen, &parser, NULL);
     printf("Parser result: %d\n", result);
+    printf("Most stack used: %lu\n", ((unsigned long)&result) - ((unsigned long)lowestStackSeen));
     
     return 0;
 }