From 6fad44af4ae20b424ff1caddc8b38957897d400a Mon Sep 17 00:00:00 2001
From: Raymaekers Luca <luca@spacehb.net>
Date: Thu, 13 Nov 2025 12:37:21 +0100
Subject: checkpoint

---
 src/haversine_processor/haversine_processor.cpp | 256 ++++++++++++++++++++++++
 1 file changed, 256 insertions(+)
 create mode 100644 src/haversine_processor/haversine_processor.cpp

(limited to 'src/haversine_processor/haversine_processor.cpp')

diff --git a/src/haversine_processor/haversine_processor.cpp b/src/haversine_processor/haversine_processor.cpp
new file mode 100644
index 0000000..a200d93
--- /dev/null
+++ b/src/haversine_processor/haversine_processor.cpp
@@ -0,0 +1,256 @@
+#include "libs/lr/lr.h"
+#define STB_SPRINTF_IMPLEMENTATION
+#include "libs/stb_sprintf.h"
+
+#include <errno.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+//~ Types
+struct str8
+{
+    u8 *Data;
+    umm Size;
+};
+#define S8Lit(String) (str8){.Data = (u8 *)(String), .Size = (sizeof((String)) - 1)}
+
+//~ Globals
+global_variable u8 LogBuffer[Kilobytes(64)];
+
+//~ Functions
+//- Debug utilities 
+void AssertErrnoNotEquals(smm Result, smm ErrorValue)
+{
+    if(Result == ErrorValue)
+    {
+        int Errno = errno;
+        Assert(0);
+    }
+}
+
+void AssertErrnoEquals(smm Result, smm ErrorValue)
+{
+    if(Result != ErrorValue)
+    {
+        int Errno = errno;
+        Assert(0);
+    }
+}
+
+void LogFormat(char *Format, ...)
+{
+    va_list Args;
+    va_start(Args, Format);
+    
+    int Length = stbsp_vsprintf((char *)LogBuffer, Format, Args);
+    
+    smm BytesWritten = write(STDOUT_FILENO, LogBuffer, Length);
+    AssertErrnoEquals(BytesWritten, Length);
+}
+
+//- Parsing utilities 
+
+b32 IsWhiteSpace(u8 Char)
+{
+    b32 Result = (Char == ' ' || Char == '\t' || Char == '\n');
+    return Result;
+}
+
+void ConsumeWhiteSpacePastChar(umm Size, u8 *In, umm *Start, u8 Char)
+{
+    umm At = *Start;
+    
+    while(At < Size && IsWhiteSpace(In[At])) At += 1;
+    At += 1;
+    
+    if(At >= Size || In[At] != Char)
+    {
+        Assert(0 && "Expected Char");
+    }
+    
+    *Start = At;
+}
+
+void ConsumePastJsonString(umm Size, u8 *In, umm *Start, str8 String)
+{
+    umm At = *Start;
+    
+    ConsumeWhiteSpacePastChar(Size, In, &At, '"');
+    
+    if(At + String.Size < Size)
+    {
+        b32 Match = true;
+        for(umm MatchIndex = 0;
+            MatchIndex < String.Size;
+            MatchIndex += 1)
+        {
+            if(In[At + MatchIndex] != String.Data[MatchIndex])
+            {
+                Match = false;
+                break;
+            }
+        }
+        
+        if(Match)
+        {
+            At += String.Size;
+            
+            if(In[At] == '"')
+            {
+                At += 1;
+            }
+            else
+            {
+                Assert(In[At] == '"');
+            }
+        }
+        else
+        {
+            Assert(Match && "Expected String");
+        }
+        
+    }
+    else
+    {
+        Assert(0 && "Expected '\"'");
+    }
+    
+    *Start = At;
+}
+
+struct parse_number_result
+{
+    f64 Value;
+    umm At;
+};
+
+void ParseNumber(umm Size, u8 *In, umm *Start, f64 *Value)
+{
+    umm At = *Start;
+    
+    while(At < Size && In[At] != '.') 
+    {
+        Assert(In[At] >= '0' && In[At] <= '9');
+        
+        At += 1;
+    }
+    Assert(In[At] == '.');
+    At += 1;
+    
+    while(At < Size && !IsWhiteSpace(In[At]))
+    {
+        Assert(In[At] >= '0' && In[At] <= '9');
+        
+        At += 1;
+    }
+    
+    *Start = At;
+}
+
+
+//-
+
+int main(int ArgsCount, char *Args[])
+{
+    
+    char *JsonFileName = 0;
+    char *AnswersFileName = 0;
+    
+    
+    if(ArgsCount >= 2)
+    {
+        JsonFileName = Args[1];
+    }
+    else
+    {
+        LogFormat("usage: %s <file.json> [answer.f64]\n", Args[0]);
+    }
+    
+    if(ArgsCount >= 3)
+    {
+        AnswersFileName = Args[1];
+    }
+    
+    if(JsonFileName)
+    {
+        int JsonFile = open(JsonFileName, O_RDONLY);
+        if(JsonFile != -1)
+        {
+            struct stat StatBuffer = {};
+            int Result = fstat(JsonFile, &StatBuffer);
+            AssertErrnoNotEquals(Result, -1);
+            
+            umm FileSize = StatBuffer.st_size;
+            u8 *JsonMemory = (u8 *)mmap(0, FileSize, PROT_READ, MAP_PRIVATE, JsonFile, 0);
+            AssertErrnoNotEquals((smm)JsonMemory, (smm)MAP_FAILED);
+            
+            f64 X0, X1, Y0, Y1;
+            
+            // Json Parsing
+            u8 *In = JsonMemory;
+            for(umm At = 0;
+                At < FileSize;
+                At += 1)
+            {
+                ConsumeWhiteSpacePastChar(FileSize, In, &At, '{');
+                ConsumePastJsonString(FileSize, In, &At, S8Lit("pairs"));
+                ConsumeWhiteSpacePastChar(FileSize, In, &At, ':');
+                ConsumeWhiteSpacePastChar(FileSize, In, &At, '[');
+                
+                // One pair
+                {                
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, '{');
+                    
+                    ConsumePastJsonString(FileSize, In, &At, S8Lit("x0"));
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, ':');
+                    while(At < FileSize && IsWhiteSpace(In[At])) At += 1;
+                    At += 1;
+                    ParseNumber(FileSize, In, &At, &X0);
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, ',');
+                    
+                    ConsumePastJsonString(FileSize, In, &At, S8Lit("y0"));
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, ':');
+                    while(At < FileSize && IsWhiteSpace(In[At])) At += 1;
+                    At += 1;
+                    ParseNumber(FileSize, In, &At, &Y0);
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, ',');
+                    
+                    ConsumePastJsonString(FileSize, In, &At, S8Lit("x1"));
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, ':');
+                    while(At < FileSize && IsWhiteSpace(In[At])) At += 1;
+                    At += 1;
+                    ParseNumber(FileSize, In, &At, &X1);
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, ',');
+                    
+                    ConsumePastJsonString(FileSize, In, &At, S8Lit("y1"));
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, ':');
+                    while(At < FileSize && IsWhiteSpace(In[At])) At += 1;
+                    At += 1;
+                    ParseNumber(FileSize, In, &At, &Y1);
+                    
+                    ConsumeWhiteSpacePastChar(FileSize, In, &At, '}');
+                }
+                
+#if 1                
+                break;
+#endif
+                
+                ConsumeWhiteSpacePastChar(FileSize, In, &At, ']');
+                ConsumeWhiteSpacePastChar(FileSize, In, &At, '}');
+            }
+            
+        }
+        
+    }
+    else
+    {
+        LogFormat("Error: File not found.\n"
+                  "usage: %s <file.json> [answer.f64]\n", Args[0]);
+    }
+    
+    
+    return 0;
+}
\ No newline at end of file
-- 
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