init commitHEADmaster

1 files changed, 102 insertions, 0 deletions

diff --git a/lex.c b/lex.c
new file mode 100644
index 0000000..db16db0
--- /dev/null
+++ b/lex.c
@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "types.h"
+
+#define size(arr) sizeof(arr) / sizeof(arr[0])
+
+char *keywords[] = {
+	"int",
+	"char",
+	"return",
+	"for",
+	"while",
+	"if", 
+	"else",
+	"elif"
+};
+
+
+char *saveptr = NULL;
+
+int lexchar(lexobj *l, char *line, char c) {
+	if (line[0] == c) {
+		l->data = NULL;
+		l->t = c;
+		saveptr = line + 1;
+		return 1;
+	}
+	return 0;
+}
+
+int lexchars(lexobj *l, char *line, char *cs) {
+	for (int i = 0; i < strlen(cs); i++) {
+		if (lexchar(l, line, cs[i])) return 1;
+	}
+	return 0;
+}
+
+lexobj lex(char *line) {
+removepadding:
+	if (line[0] == ' ') line++;
+	if (line[0] == ' ') goto removepadding;
+
+	static lexobj l;
+
+	if (isdigit(line[0])) {
+		static char num[256];
+		int ptr = 0;
+		while (isdigit(line[0])) {
+			num[ptr] = line[0];
+			ptr++;
+			line++;
+		}
+		num[ptr] = 0;
+		saveptr = line;
+		l.data = num;
+		l.t = INTLIT;
+		return l;
+	}
+
+	if (lexchars(&l, line, "(){};+-*/")) return l;
+
+	for (int i = 0; i < size(keywords); i++) {
+		if (strstr(line, keywords[i]) == line) {
+			line += strlen(keywords[i]);
+			saveptr = line;
+			if (line[0] != ' ') goto retry;
+			l.data = keywords[i];
+			l.t = KEYWORD;
+			return l;
+		}
+retry:
+		continue;
+	}
+
+	char *data = strchr(line, '(');
+	*data = 0;
+	l.data = strdup(line);
+	line += data - line;
+	*data = '(';
+	saveptr = line;
+
+	return l;
+}
+
+void stripwhitespace(char *line) {
+	char *out = malloc(256);
+	int ptr = 0;
+	for (int i = 0; i < strlen(line); i++) {
+		if (line[i] == '\t' || line[i] == '\n'
+				|| line[i] == '\v') continue;
+		else {
+			out[ptr] = line[i];
+			ptr++;
+		}
+	}
+	out[ptr] = 0;
+
+	memcpy(line, out, 256);
+}