Initial import of existing source code

This is based off of snaptoken's "Build Your Own Text Editor" tutorial
at https://viewsourcecode.org/snaptoken/kilo/.

1 files changed, 197 insertions, 0 deletions

diff --git a/syntax.c b/syntax.c
new file mode 100644
index 0000000..ffaae4a
--- /dev/null
+++ b/syntax.c
@@ -0,0 +1,197 @@
+#include "syntax.h"
+
+#include <string.h>
+#include "editor.h"
+
+char* c_highlight_extensions[] = { ".c", ".h", ".cpp", ".cc", NULL };
+
+char* c_highlight_keywords[] = {
+	"switch", "if", "while", "for", "break", "continue", "return", "else",
+	"struct", "union", "typedef", "static", "enum", "class", "case",
+	"#include", "#define", "#ifdef", "#ifndef",
+
+	"int|", "long|", "double|", "float|", "char|", "unsigned|", "signed|",
+	"void|", NULL
+};
+
+struct editor_syntax highlight_database[] = {
+	{
+		"c",
+		c_highlight_extensions,
+		c_highlight_keywords,
+		"//", "/*", "*/",
+		HIGHLIGHT_FLAG_NUMBERS | HIGHLIGHT_FLAG_STRINGS
+	}
+};
+
+int is_separator(int c)
+{
+	return isspace(c) || c == '\0' || strchr(",.()+-/*=~%<>[];", c) != NULL;
+}
+
+void editor_update_syntax(struct editor_state* editor, struct editor_row* row)
+{
+	row->highlight = realloc(row->highlight, row->render_size);
+	memset(row->highlight, HIGHLIGHT_NORMAL, row->render_size);
+
+	if (editor->syntax == NULL)
+		return;
+
+	char** keywords = editor->syntax->keywords;
+
+	// TODO: Remove
+	char* single_line_comment_start = editor->syntax->single_line_comment_start;
+	char* multi_line_comment_start = editor->syntax->multi_line_comment_start;
+	char* multi_line_comment_end = editor->syntax->multi_line_comment_end;
+	
+	int single_line_comment_start_length = single_line_comment_start ? strlen(single_line_comment_start) : 0;
+	int multi_line_comment_start_length = multi_line_comment_start ? strlen(multi_line_comment_start) : 0;
+	int multi_line_comment_end_length = multi_line_comment_end ? strlen(multi_line_comment_end) : 0;
+
+	int previous_separator = 1;
+	int in_string = 0;
+	int in_comment = (row->index > 0 && editor->rows[row->index - 1].highlight_open_comment);
+
+	int i = 0;
+	while (i < row->render_size) {
+		char c = row->render[i];
+		unsigned char previous_highlight = (i > 0) ? row->highlight[i - 1] : HIGHLIGHT_NORMAL;
+
+		if (single_line_comment_start_length && !in_string && !in_comment) {
+			if (!strncmp(&row->render[i], single_line_comment_start, single_line_comment_start_length)) {
+				memset(&row->highlight[i], HIGHLIGHT_COMMENT, row->render_size - i);
+				break;
+			}			
+		}
+
+		if (multi_line_comment_start_length && multi_line_comment_end_length && !in_string) {
+			if (in_comment) {
+				row->highlight[i] = HIGHLIGHT_MULTILINE_COMMENT;
+				if (!strncmp(&row->render[i], multi_line_comment_end, multi_line_comment_end_length)) {
+					memset(&row->highlight[i], HIGHLIGHT_MULTILINE_COMMENT, multi_line_comment_end_length);
+
+					i += multi_line_comment_end_length;
+					in_comment = 0;
+					previous_separator = 1;
+					continue;
+				} else {
+					i++;
+					continue;
+				}
+			} else if (!strncmp(&row->render[i], multi_line_comment_start, multi_line_comment_start_length)) {
+				memset(&row->highlight[i], HIGHLIGHT_MULTILINE_COMMENT, multi_line_comment_start_length);
+				i += multi_line_comment_start_length;
+				in_comment = 1;
+				continue;
+			}
+		}
+
+		if (editor->syntax->flags & HIGHLIGHT_FLAG_STRINGS) {
+			if (in_string) {
+				row->highlight[i] = HIGHLIGHT_STRING;
+
+				if (c == '\\' && i + 1 < row->render_size) {
+					row->highlight[i + 1] = HIGHLIGHT_STRING;
+					i += 2;
+					continue;
+				}
+
+				if (c == in_string)
+					in_string = 0;
+
+				i++;
+				previous_separator = 1;
+				continue;
+			} else {
+				if (c == '"' || c == '\'') {
+					in_string = c;
+					row->highlight[i] = HIGHLIGHT_STRING;
+					i++;
+					continue;
+				}
+			}
+		}
+
+		if (editor->syntax->flags & HIGHLIGHT_FLAG_NUMBERS) {
+			if ((isdigit(c) && (previous_separator || previous_highlight == HIGHLIGHT_NUMBER)) || (c == '.' && previous_highlight == HIGHLIGHT_NUMBER)) {
+				row->highlight[i] = HIGHLIGHT_NUMBER;
+				i++;
+				previous_separator = 0;
+				continue;
+			}
+		}
+
+		if (previous_separator) {
+			int j;
+			for (j = 0; keywords[j]; j++) {
+				int keyword_length = strlen(keywords[j]);
+				int is_secondary = keywords[j][keyword_length - 1] == '|';
+
+				if (is_secondary)
+					keyword_length--;
+
+				if (!strncmp(&row->render[i], keywords[j], keyword_length) && is_separator(row->render[i + keyword_length])) {
+					memset(&row->highlight[i], is_secondary ? HIGHLIGHT_KEYWORD2 : HIGHLIGHT_KEYWORD1, keyword_length);
+					i += keyword_length;
+					break;
+				}
+			}
+			if (keywords[j] != NULL) {
+				previous_separator = 0;
+				continue;
+			}
+		}
+
+		previous_separator = is_separator(c);
+		i++;
+	}
+
+	int changed = (row->highlight_open_comment != in_comment);
+	row->highlight_open_comment = in_comment;
+	if (changed && row->index + 1 < editor->row_count)
+		editor_update_syntax(editor, &editor->rows[row->index + 1]);
+}
+
+int editor_syntax_to_colour(int highlight)
+{
+	switch (highlight) {
+		case HIGHLIGHT_MULTILINE_COMMENT:
+		case HIGHLIGHT_COMMENT: return 36;
+		case HIGHLIGHT_KEYWORD1: return 33;
+		case HIGHLIGHT_KEYWORD2: return 32;
+		case HIGHLIGHT_STRING: return 35;
+		case HIGHLIGHT_NUMBER: return 31;
+		case HIGHLIGHT_MATCH: return 34;
+		default: return 37;
+	}
+}
+
+void editor_select_syntax_highlight(struct editor_state* editor)
+{
+	editor->syntax = NULL;
+	
+	if (editor->filename == NULL)
+		return;
+
+	char* extension = strrchr(editor->filename, '.');
+
+	for (unsigned int j = 0; j < HIGHLIGHT_DATABASE_ENTRY_COUNT; j++) {
+		struct editor_syntax* syntax = &highlight_database[j];
+		unsigned int i = 0;
+
+		while (syntax->filetype_match[i]) {
+			int is_extension = (syntax->filetype_match[i][0] == '.');
+			if ((is_extension && extension && !strcmp(extension, syntax->filetype_match[i])) || (!is_extension && strstr(editor->filename, syntax->filetype_match[i]))) {
+				editor->syntax = syntax;
+
+				int file_row;
+				for (file_row = 0; file_row < editor->row_count; file_row++) {
+					editor_update_syntax(editor, &editor->rows[file_row]);
+				}
+				
+				return;
+			}
+			i++;
+		}
+	}
+}