C API

README.md

@@ -112,6 +112,41 @@ Minimalistic C++ app example: [https://github.com/adonmo/meos-cpp-example](https
 
 C++ API Reference: [https://adonmo.github.io/meos/](https://adonmo.github.io/meos/)
 
+## C
+
+MEOS can also be accessed from C.
+
+Here is an example code on how to do this:
+
+```c
+#include "meos/meos_c.h"
+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+    struct MEOS_TBox* tbox = MEOS_newTBox(12.34, 56.78);
+    double xmin = MEOS_TBox_xmin(tbox);
+    printf("%lf\n", xmin);
+    MEOS_deleteTBox(tbox);
+}
+```
+To compile the above code, you would need `libmeos_c.so`. If you do not have it, build it first by running:
+```sh
+cmake -B build/capi -S capi
+cmake --build build/capi
+```
+
+After saving the above file as `main.c`, run the following commands to build and run it:
+
+```sh
+gcc -I/<path_to_meos>/capi/include -c main.c -o main.o
+g++ -L/<path_to_meos>/build/capi main.o -l:libmeos_c.so -o main
+LD_LIBRARY_PATH=/<path_to_meos>/build/capi ./main
+```
+If you see the following output, you have succesfully used MEOS from C!
+```
+12.340000
+```
+
 ## Contributing
 
 Issues and pull requests are welcome.

capi/CMakeLists.txt

@@ -0,0 +1,52 @@
+cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
+
+project(
+  meos_c
+  LANGUAGES C CXX
+)
+# Get version from VERSION file instead of hardcoding here
+# This is so that we can maintain a single version across C/C++ and Python
+file(STRINGS ../VERSION LIBMEOS_VERSION)
+set(PROJECT_VERSION ${LIBMEOS_VERSION})
+message(STATUS "MEOS: v${LIBMEOS_VERSION}")
+
+# ---- Dependencies ----
+
+include(../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME libmeos
+  SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/..
+)
+
+# ---- Create library ----
+
+file(GLOB_RECURSE headers CONFIGURE_DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/include/*.h")
+file(GLOB_RECURSE sources CONFIGURE_DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/source/*.cpp")
+add_library(meos_c SHARED ${headers} ${sources})
+target_link_libraries(meos_c libmeos)
+
+if(MSVC)
+    add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+endif()
+
+# being a cross-platform target, we enforce standards conformance on MSVC
+target_compile_options(meos_c PUBLIC "$<$<BOOL:${MSVC}>:/permissive->")
+
+target_include_directories(meos_c
+  PUBLIC
+    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include/${PROJECT_NAME}-${PROJECT_VERSION}>
+)
+
+message(${PROJECT_SOURCE_DIR}/include)
+
+packageProject(
+  NAME ${PROJECT_NAME}
+  VERSION ${PROJECT_VERSION}
+  BINARY_DIR ${PROJECT_BINARY_DIR}
+  INCLUDE_DIR ${PROJECT_SOURCE_DIR}/include
+  INCLUDE_DESTINATION include/${PROJECT_NAME}-${PROJECT_VERSION}
+  VERSION_HEADER "${VERSION_HEADER_LOCATION}"
+  DEPENDENCIES ""
+)

capi/include/meos/meos_c.h

@@ -0,0 +1,104 @@
+#pragma once
+
+#include <string.h>
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct MEOS_Period MEOS_Period;
+typedef struct MEOS_TBox MEOS_TBox;
+typedef struct MEOS_TFloatInst MEOS_TFloatInst;
+typedef struct MEOS_TFloatSeq MEOS_TFloatSeq;
+typedef struct MEOS_TFloatSeqSet MEOS_TFloatSeqSet;
+
+typedef enum {
+  MEOS_Interpolation_Stepwise,
+  MEOS_Interpolation_Linear,
+} MEOS_Interpolation;
+
+/*****************************************************************************
+ * TBox
+ *****************************************************************************/
+
+MEOS_TBox *MEOS_newTBox(double const xmin, double const xmax);
+
+double MEOS_TBox_xmin(MEOS_TBox *tbox);
+double MEOS_TBox_xmax(MEOS_TBox *tbox);
+
+void MEOS_deleteTBox(MEOS_TBox *tbox);
+
+/*****************************************************************************
+ * Period
+ *****************************************************************************/
+
+// Constructor with a string
+MEOS_Period *MEOS_newPeriod(char *serialized);
+// Constructor with two timestamps
+MEOS_Period *MEOS_newPeriod_TT(time_t lower, time_t upper);
+// Constructor with two timestamps and two boolean bounds
+MEOS_Period *MEOS_newPeriod_TTBB(time_t lower, time_t upper, bool lower_inc, bool upper_inc);
+
+char *MEOS_Period_str(MEOS_Period *period);
+
+void MEOS_deletePeriod(MEOS_Period *period);
+
+/*****************************************************************************
+ * TFloatInst
+ *****************************************************************************/
+
+// Constructor with a string
+MEOS_TFloatInst *MEOS_newTFloatInst(char *serialized);
+// Constructor with a value and timestamp
+MEOS_TFloatInst *MEOS_newTFloatInst_VT(float value, time_t timestamp);
+
+float MEOS_TFloatInst_value(MEOS_TFloatInst *tfloatinst);
+time_t MEOS_TFloatInst_timestamp(MEOS_TFloatInst *tfloatinst);
+char *MEOS_TFloatInst_str(MEOS_TFloatInst *tfloatinst);
+
+void MEOS_deleteTFloatInst(MEOS_TFloatInst *tfloatinst);
+
+/*****************************************************************************
+ * TFloatSeq
+ *****************************************************************************/
+
+// Constructor with a string
+MEOS_TFloatSeq *MEOS_newTFloatSeq(char *serialized);
+// Constructor with a set of instants, two boolean bounds and interpolation
+MEOS_TFloatSeq *MEOS_newTFloatSeq_IBBI(MEOS_TFloatInst **instants, int count, bool lower_inc,
+                                       bool upper_inc, MEOS_Interpolation interpolation);
+// Constructor with a set of instants as strings, two boolean bounds and interpolation
+MEOS_TFloatSeq *MEOS_newTFloatSeq_IsBBI(char **instants, int count, bool lower_inc, bool upper_inc,
+                                        MEOS_Interpolation interpolation);
+
+bool MEOS_TFloatSeq_lower_inc(MEOS_TFloatSeq *tfloatseq);
+bool MEOS_TFloatSeq_upper_inc(MEOS_TFloatSeq *tfloatseq);
+MEOS_Interpolation MEOS_TFloatSeq_interpolation(MEOS_TFloatSeq *tfloatseq);
+MEOS_TFloatInst **MEOS_TFloatSeq_instants(MEOS_TFloatSeq *tfloatseq, int *count);
+char *MEOS_TFloatSeq_str(MEOS_TFloatSeq *tfloatseq);
+
+void MEOS_deleteTFloatSeq(MEOS_TFloatSeq *tfloatseq);
+
+/*****************************************************************************
+ * TFloatSeqSet
+ *****************************************************************************/
+
+// Constructor with a string
+MEOS_TFloatSeqSet *MEOS_newTFloatSeqSet(char *serialized);
+// Constructor with a set of sequences and interpolation
+MEOS_TFloatSeqSet *MEOS_newTFloatSeqSet_SI(MEOS_TFloatSeq **sequences, int count,
+                                           MEOS_Interpolation interpolation);
+// Constructor with a set of sequences as strings and interpolation
+MEOS_TFloatSeqSet *MEOS_newTFloatSeqSet_SsI(char **sequences, int count,
+                                            MEOS_Interpolation interpolation);
+
+MEOS_TFloatSeq **MEOS_TFloatSeqSet_sequences(MEOS_TFloatSeqSet *tfloatseqset, int *count);
+MEOS_TFloatSeqSet *MEOS_TFloatSeqSet_atPeriod(MEOS_TFloatSeqSet *tfloatseqset, MEOS_Period *period);
+char *MEOS_TFloatSeqSet_str(MEOS_TFloatSeqSet *tfloatseqset);
+
+void MEOS_deleteTFloatSeqSet(MEOS_TFloatSeqSet *tfloatseqset);
+
+#ifdef __cplusplus
+}
+#endif