3
namespace VQDR.Expression {
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public string to_string () {
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// We add one as we have an invalid case.
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static_assert (CharType._NUM_VAL == 10 + 1);
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assert_not_reached ();
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* Determine character type.
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* @param ch Character to be checked.
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* @return The character type.
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public static CharType from_char (char ch) {
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if ((ch >= 'a' && ch <= 'z') || (ch>= 'A' && ch <= 'Z' )) {
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private static string[] EMPTY_VAR_KEYS = new string[0];
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private Context context = null;
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/** Contains the used variable names. */
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private string[] variable_keys;
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/** contains the used variables and their last value. */
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private HashTable<string, Variable?> variable_cache;
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/** Will contain the Root of the token tree.
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* Asumes that there it has no parents.*/
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private Token root_token;
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private bool parsed = false;
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private bool evaluated_once;
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private string internal_experisson;
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public string expression {
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get {return internal_experisson;}
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set {internal_experisson = value;
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expression_size = value.length;
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private size_t expression_size = 0;
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private char cur_char = 0;
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private int32 index = -1;
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private FastNumber result_value;
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private FastNumber result_max_value;
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private FastNumber result_min_value;
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private string result_string;
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private Error? error;
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public Parser (string expression) {
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this.expression = expression;
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this.expression_size = expression.length;
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this.cur_char = expression[0];
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public Parser.empty () {
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public void reset () {
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evaluated_once = false;
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result_value = FastNumber (0);
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result_min_value = FastNumber (0);
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result_max_value = FastNumber (0);
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variable_cache.remove_all ();
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variable_keys = EMPTY_VAR_KEYS;
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* Parse the expersson string.
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public void parse () throws ParseError {
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throw new ParseError.ALLREADY_PARSED
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("Data has allparsed been parsed.");
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while (this.index <= this.expression_size) {
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switch (CharType.from_char (this.cur_char)) {
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this.parse_advance ();
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assert_not_reached ();
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* advance the parser.
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private void parse_advance () {
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if (this.index < this.expression_size && this.cur_char != '\0') {
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this.cur_char = this.expression[this.index];
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protected bool valid_bounds () {
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if (!evaluated_once) {
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if (context != null) {
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foreach (var key in variable_keys) {
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if (!context.has_name (key) ||
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!variable_cache.get (key).equals (context.get_variable (key))) {
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err_print_ln ("Something went wrong: (%: %)", e.domain, e.message);
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assert_not_reached ();
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protected void set_variable_cach_values () {
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if (context != null) {
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foreach (var key in variable_keys) {
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variable_cache.insert (key, Variable.copy
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(context.get_variable (key)));
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err_print_ln ("Something went wrong: (%: %)", e.domain, e.message);
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assert_not_reached ();
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protected void set_error (Error e) {
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result_string = "Error";
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set_variable_cach_values ();
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protected void set_result (Token root_token) {
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evaluated_once = true;
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result_value = root_token.result_value;
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result_max_value = root_token.result_max_value;
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result_min_value = root_token.result_min_value;
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result_string = root_token.result_string;
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set_variable_cach_values ();
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protected void evaluate () throws Error {
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if (root_token == null) {
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root_token = new RootToken (root);
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root_token.evaluate (context);
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set_result (root_token);
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* Add a note (operator) to the stack after popping it's parameters.
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* @param operand_stack stack
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* @param operator operator.
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protected void add_node (Stack<Token> operand_stack,
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Token operator) throws Error {
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if (operator is FunctionToken) {
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FunctionToken funk = (FunctionToken) operator;
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int32 param_num = funk.next_child_num;
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for (var i = 0; i < param_num; i++) {
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Token param_child = operand_stack.pop ();
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funk.set_child (param_num - 1, param_child);
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operand_stack.push (funk);
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} else if (operator is UnaryOperator &&
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((UnaryOperator) operator).is_unary) {
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if (operand_stack.elements < 1) {
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throw new OperandError.MISSING_OPERAND
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(@"Missing operand. Position: $(operator.position)");
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if (operand_stack.elements < 2) {
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throw new OperandError.MISSING_OPERAND
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(@"Missing operand. Position: $(operator.position)");
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operator.set_right_child (operand_stack.pop ());
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operator.set_left_child (operand_stack.pop ());
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operand_stack.push (operator);
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} // end of Parser class
added
removed
src/libvqdr/parser.vala
