3 files changed, 280 insertions, 0 deletions
diff --git a/old/parser.c b/old/parser.c
new file mode 100644
index 0000000..5e94e79
--- /dev/null
+++ b/old/parser.c
@@ -0,0 +1,225 @@
+#include <parser.h>
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+static const char *interpreter_operators = "=(";
+
+bool strcmp(const char *a, const char *b)
+{
+	int i = 0;
+	for (; a[i] == b[i] && a[i] != '\0'; i++);
+	return a[i] == b[i];
+}
+
+bool strncmp(const char *a, const char *b, int count)
+{
+	int i = 0;
+	for (; a[i] == b[i] && i < count; i++);
+	return i == count;
+}
+
+uint8_t isalpha(char c)
+{
+	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
+}
+
+uint8_t isnum(char c)
+{
+	return (c >= '0' && c <= '9');
+}
+
+uint8_t isname(char c)
+{
+	return isalpha(c) || isnum(c);
+}
+
+uint8_t isspace(char c)
+{
+	return (c == ' ' || c == '\t' || c == '\n');
+}
+
+uint8_t isoper(char c)
+{
+	for (uint8_t i = 0; i < sizeof(interpreter_operators); i++) {
+		if (c == interpreter_operators[i])
+			return 1;
+	}
+
+	return 0;
+}
+
+void interpreter_init(interpreter *interp)
+{
+	interp->status = READY;
+	interp->vcount = 0;
+	interp->vars = (variable *)calloc(32, sizeof(variable));
+	interp->names = (char **)calloc(32, sizeof(char *));
+	interp->stack = (stack_t *)calloc(64, sizeof(stack_t));
+}
+
+void interpreter_define_value(interpreter *interp, const char *name, int32_t value)
+{
+	interp->names[interp->vcount] = (char *)name; 
+	interp->vars[interp->vcount].nameidx = interp->vcount;
+	interp->vars[interp->vcount].type = VALUE;
+	interp->vars[interp->vcount].value = (uint32_t)value;
+	interp->vcount++;
+}
+
+void interpreter_define_cfunc(interpreter *interp, const char *name, func_t addr)
+{
+	interp->names[interp->vcount] = (char *)name;
+	interp->vars[interp->vcount].nameidx = interp->vcount;
+	interp->vars[interp->vcount].type = CFUNCTION;
+	interp->vars[interp->vcount].value = (uint32_t)addr;
+	interp->vcount++;
+}
+
+int32_t interpreter_get_value(interpreter *interp, const char *name)
+{
+	for (uint16_t i = 0; i < interp->vcount; i++) {
+		if (!strcmp(interp->names[i], name))
+			return (int32_t)interp->vars[i].value;
+	}
+
+	return 0;
+}
+
+/**
+ * doline section
+ */
+
+bool namencmp(const char *name, const char *s)
+{
+	uint16_t i;
+	for (i = 0; name[i] == s[i] && s[i] != '\0'; i++);
+	return (name[i] == '\0' && !isname(s[i]));
+}
+
+uint16_t spacecount(const char *s)
+{
+	uint16_t i;
+	for (i = 0; isspace(s[i]); i++);
+	return i;
+}
+
+char *copystr(const char *s, char end)
+{
+	uint16_t len = 0;
+	while (s[len++] != end);
+	char *buf = (char *)malloc(len);
+	for (uint16_t i = 0; i < len; i++)
+		buf[i] = s[i];
+	return buf;
+}
+
+char *copysubstr(const char *s, int end)
+{
+	char *buf = (char *)malloc(end);
+	for (uint16_t i = 0; i < end; i++)
+		buf[i] = s[i];
+	return buf;
+}
+
+variable *interpreter_getvar(interpreter *interp, const char *line)
+{
+	for (uint16_t i = 0; i < interp->vcount; i++) {
+		if (namencmp(interp->names[i], line))
+			return &interp->vars[i];
+	}
+
+	return 0;
+}
+
+int interpreter_doline(interpreter *interp, const char *line)
+{
+	variable *bits[16];
+	uint16_t offset = 0, boffset = 0;
+
+	// check for var/func set or usage
+	int end;
+getvar:
+	for (end = 0; isname(line[end]); end++);
+	variable *var = interpreter_getvar(interp, line);
+
+	if (var != 0) {
+		bits[boffset++] = var;
+	} else {
+		// defining new variable
+		interpreter_define_value(interp, copysubstr(line, end), 0);
+		goto getvar; // try again
+	}
+
+	// skip whitespace/name
+	offset += end;
+	offset += spacecount(line + offset); 
+
+	if (boffset == 0 && line[offset] != '=')
+		return -1; // variable not found
+
+	// find operator
+	if (line[offset] == '\0') {
+		// print value
+		return -99;
+	} else if (line[offset] == '=') {
+		// assignment/expression
+		offset++;
+		offset += spacecount(line + offset);
+		bits[0]->value = (uint32_t)copystr(line + offset, '\0');
+	} else if (line[offset] == '(') {
+		// function call
+		offset++;
+		if (bits[0]->type != FUNCTION && bits[0]->type != CFUNCTION)
+			return -2;
+		offset += spacecount(line + offset);
+		
+		// collect arg offsets
+		uint16_t offsets[8];
+		uint8_t ooffset = 0;
+		while (line[offset] != ')' && line[offset] != '\0') {
+			offsets[ooffset] = offset;
+			offset += spacecount(line + offset);
+
+			uint8_t isvn = 1;
+			do {
+				if (line[offset] == ' ' || line[offset] == '\t') {
+					offset += spacecount(line + offset);
+					isvn = 0;
+				}
+
+				if (line[offset] == ',') {
+					offset++;
+					ooffset++;
+					break;
+				} else if (line[offset] == ')') {
+					ooffset++;
+					break;
+				} else if (isvn == 0) {
+					return -3;
+				}
+			} while (++offset);
+		}
+
+		// populate stack
+		for (uint8_t i = 0; i < ooffset; i++) {
+			uint16_t j;
+			for (j = offsets[i]; line[j] != ' ' && line[j] != '\t' &&
+					line[j] != ',' && line[j] != ')'; j++);
+			j -= offsets[i];
+
+			variable *var = interpreter_getvar(interp, line + offsets[i]);
+			if (var != 0)
+				interp->stack[i] = copystr((char *)var->value, '\0');
+			else
+				interp->stack[i] = copysubstr(line + offsets[i], j);
+		}
+
+		((func_t)bits[0]->value)(interp->stack);
+	} else {
+		return -2; // invalid operation
+	}
+
+	return 0;
+}
+
diff --git a/old/parser.h b/old/parser.h
new file mode 100644
index 0000000..c6a2b17
--- /dev/null
+++ b/old/parser.h
@@ -0,0 +1,31 @@
+#ifndef PARSER_H_
+#define PARSER_H_
+
+#include <variable.h>
+
+typedef void *stack_t;
+
+typedef struct {
+	uint16_t status;
+	uint16_t vcount;
+	variable *vars;
+	char **names;
+	stack_t *stack;
+} interpreter;
+
+enum status {
+	READY = 0
+};
+
+typedef void (*func_t)(stack_t *);
+
+void interpreter_init(interpreter *);
+
+void interpreter_define_value(interpreter *, const char *, int32_t);
+void interpreter_define_cfunc(interpreter *, const char *, func_t);
+
+int32_t interpreter_get_value(interpreter *, const char *);
+
+int interpreter_doline(interpreter *, const char *);
+
+#endif // PARSER_H_
diff --git a/old/variable.h b/old/variable.h
new file mode 100644
index 0000000..fd84a6e
--- /dev/null
+++ b/old/variable.h
@@ -0,0 +1,24 @@
+#ifndef TOKEN_H_
+#define TOKEN_H_
+
+#include <stdint.h>
+
+typedef struct {
+	uint16_t nameidx;
+	uint8_t type;
+	uint8_t info;
+	uint32_t value;
+} variable;
+
+#define INFO_ARGS(x)	((x) & 0x07)
+#define INFO_RET	(1 << 3)
+
+enum vartype {
+	VALUE = 0,
+	VARIABLE,
+	OPERATOR,
+	FUNCTION,
+	CFUNCTION
+};
+
+#endif // TOKEN_H_