1 files changed, 93 insertions, 0 deletions
diff --git a/im.h b/im.h
new file mode 100644
index 0000000..4980938
--- /dev/null
+++ b/im.h
@@ -0,0 +1,93 @@
+#include "imtable.h"
+#define IM_BUFFER_LEN 32
+char im_buffer[IM_BUFFER_LEN];
+char im_buffer_pos = 0;
+//recursive search, returns -1 on failure
+//searches from [start, end)
+int im_search(char * input, int start, int end) {
+	// 0 width search
+	if (end <= start) {
+		return -1;
+	}
+	//test for middle, works even for 1 width middle=start
+	int middle = start + (end-start)/2;
+	printf("testing:%s\n",im_table[middle][0]);
+	int test = strncmp(im_table[middle][0], input, IM_TABLE_ENTRY_LEN);
+	if (test == 0) {
+		return middle;
+	}
+	//special case for width 1,2 region
+	if ((end - start) == 1) {
+		if (test == 0) {
+			return start;
+		} else {
+			return -1;
+		}
+	}
+	if (test == 0) {
+		return 0;
+	} else {
+		if (test > 0) {
+			return im_search(input,start,middle);
+		} else {
+			return im_search(input,middle,end);
+		}
+	}
+	
+}
+//returns output len, since we want to be able to handle null bytes as well
+int update_im_state(char input, char * output) {
+	if ( ('a' <= input <= 'z')||('0' <= input <= '9')||(input == ' ') ) {
+		if (im_buffer_pos < IM_BUFFER_LEN) {
+			im_buffer[im_buffer_pos] = input;
+			im_buffer_pos++;
+		} else {
+			//passthrough
+			output[0] = input;
+			output[1] = 0;
+			return 1;
+		}
+	}
+	int im_entry = im_search(im_buffer,0, IM_TABLE_LEN);
+	if (im_entry != -1) {
+		strncpy(output, im_table[im_entry][1], IM_TABLE_ENTRY_LEN);
+		im_buffer[0] = 0;
+		im_buffer_pos = 0;
+		return strlen(im_table[im_entry][1]);
+	}
+	//these only do something if there's something in the buffer, otherwise
+	//passthrough
+	if (im_buffer_pos > 0) {
+		switch (input) {
+			//escape, cancels
+			case 0x1B:
+				im_buffer[0] = 0;
+				im_buffer_pos = 0;
+				return 0;
+			break;
+			//enter, enters the buffer
+			case 0x0A:
+				for (int i = 0; i <im_buffer_pos; i++) {
+					output[i] = im_buffer[i];
+				}
+				output[im_buffer_pos] = 0;
+				int tmp = im_buffer_pos;
+				im_buffer_pos = 0;
+				return tmp;
+			break;
+			//backspace
+			case 0x08:
+				if (im_buffer_pos > 0) {
+					im_buffer_pos--;
+					im_buffer[im_buffer_pos] = 0;
+				}
+				return 0;
+			break;
+		}
+	}
+	//default behavior of passthrough
+	output[0] = input;
+	output[1] = 0;
+	return 1;
+	
+}