mobile: add sample android application (HelloECL)

Developed by Sylvain Agenau, added to the repository by Evrim Ulu with
a few minor fixes by Daniel Kochmański.

examples/android/jni/org_lisp_ecl_EmbeddedCommonLisp.c

@@ -0,0 +1,134 @@
+#include <assert.h>
+
+#if ANDROID
+#include <android/log.h>
+#endif
+
+#include <string.h>
+#include <jni.h>
+#include <pthread.h>
+#include <stdio.h>
+
+#include <ecl/ecl.h>
+#include "ecl_boot.h"
+
+#if ANDROID
+#define ECL_TAG "ecl-native"
+#define LOGI(...) ((void)__android_log_print(ANDROID_LOG_INFO, ECL_TAG, __VA_ARGS__))
+#define LOGW(...) ((void)__android_log_print(ANDROID_LOG_WARN, ECL_TAG, __VA_ARGS__))
+#define LOGE(...) ((void)__android_log_print(ANDROID_LOG_ERROR, ECL_TAG, __VA_ARGS__))
+#define LOGV(...) ((void)__android_log_print(ANDROID_LOG_VERBOSE, ECL_TAG, __VA_ARGS__))
+#else
+#define LOGI(...)
+#define LOGW(...)
+#define LOGE(...)
+#endif
+
+#define jni_ecl_read_from_string(x) si_string_to_object(1, x)
+
+/*
+ * Class:     org_lisp_ecl_EmbeddedCommonLisp
+ * Method:    start
+ * Signature: ()V
+ */
+JNIEXPORT void JNICALL
+Java_org_lisp_ecl_EmbeddedCommonLisp_start(JNIEnv *env, jobject this, 
+					   jstring path) {
+
+  const char *lisp_dir = (*env)->GetStringUTFChars(env, path, NULL);  
+  LOGI("ECL starting: *default-pathname-defaults* to: %s\n", lisp_dir);
+  ecl_boot(lisp_dir);
+  LOGI("ECL started.");	
+};
+
+/* This was fun to make UTF8 work across Java-C-Lisp boundaries.
+   -evrim, 2014. */
+cl_object java_string_to_ecl_string(JNIEnv *env, jstring str) {
+  const jchar *txt = (*env)->GetStringChars(env, str, NULL);
+  jsize len = (*env)->GetStringLength(env, str);
+  cl_object ecl_txt = ecl_alloc_simple_extended_string(len);
+  cl_index i;
+
+  for (i=0;i<len;i++) {
+    ecl_txt->string.self[i] = txt[i];
+  };
+  
+  (*env)->ReleaseStringChars(env, str, txt);
+
+  return ecl_txt;
+}
+
+
+jstring ecl_object_to_java_string(JNIEnv *env, cl_object o) {
+  jstring ret;
+  if (ECL_EXTENDED_STRING_P(o)) {
+    LOGI("ecl->java extended string of fillp: %d, dim: %d",
+	 o->string.fillp,
+	 o->string.dim);
+    
+    jsize len = o->string.fillp;
+    jchar *arr = malloc(sizeof(jchar)*(len+1));
+    cl_index i;
+    for (i=0; i<len; i++) {
+      arr[i] = o->string.self[i];
+    }
+    arr[len] = 0;
+    ret = (*env)->NewString(env, arr, len);
+    free(arr);
+  } else if (ECL_STRINGP(o)) {
+    LOGI("ecl->java base string of len %d: %s",
+	 o->base_string.dim,
+	 o->base_string.self);
+
+    ret = (*env)->NewStringUTF(env, 
+			       (const char*)o->base_string.self);
+  } else {
+    LOGI("ecl->java not a string, coercing");
+    return ecl_object_to_java_string(env, cl_princ_to_string(o));
+  }
+
+  return ret;
+}
+
+/*
+ * Class:     org_lisp_ecl_EmbeddedCommonLisp
+ * Method:    exec
+ * Signature: (Ljava/lang/String;)Ljava/lang/String;
+ */
+JNIEXPORT jstring JNICALL
+Java_org_lisp_ecl_EmbeddedCommonLisp_exec(JNIEnv *env, jobject this, jstring str) {
+  jstring ret;
+  cl_object txt = java_string_to_ecl_string(env, str);
+  cl_object result = si_safe_eval(3, jni_ecl_read_from_string(txt), Cnil, OBJNULL);
+  
+  if (result) {
+    ret = ecl_object_to_java_string(env, result);
+  } else {
+    ret = (*env)->NewStringUTF(env, "ERROR in eval");
+  }
+  
+  return ret;
+};
+
+#undef jni_ecl_read_from_string
+
+/*
+ * Class:     org_lisp_ecl_EmbeddedCommonLisp
+ * Method:    exec_
+ * Signature: (Ljava/lang/String;)Ljava/lang/String;
+ */
+JNIEXPORT jstring JNICALL
+Java_org_lisp_ecl_EmbeddedCommonLisp_exec_(JNIEnv *env, jobject this, jstring str) {
+  jstring ret;
+  const char *cmd = (*env)->GetStringUTFChars(env, str, NULL);
+  cl_object result = si_safe_eval(3, c_string_to_object(cmd),
+				  Cnil, OBJNULL);
+
+  if (result) {
+    cl_object out = si_coerce_to_base_string(cl_princ_to_string(result));
+    ret = (*env)->NewStringUTF(env, (const char*) out->base_string.self);
+  } else {
+    ret = (*env)->NewStringUTF(env, "ERROR in eval");
+  }
+  return ret;
+};