infix notation parser almost done; preparing the evaluator and variables lookup

[netdata.git] / profile / test-eval.c

diff --git a/profile/test-eval.c b/profile/test-eval.c
new file mode 100644 (file)
index 0000000..509eab5
--- /dev/null
+++ b/profile/test-eval.c
@@ -0,0 +1,165 @@
+
+/*
+ * 1. build netdata (as normally)
+ * 2. cd profile/
+ * 3. compile with:
+ *    gcc -O1 -ggdb -Wall -Wextra -I ../src/ -I ../ -o test-eval test-eval.c ../src/log.o ../src/eval.o ../src/common.o -pthread
+ *
+ */
+
+#include "common.h"
+
+void netdata_cleanup_and_exit(int ret) { exit(ret); }
+
+void indent(int level, int show) {
+       int i = level;
+       while(i--) printf(" |  ");
+       if(show) printf(" \\_ ");
+       else printf(" \\_  ");
+}
+
+void print_operand(EVAL_OPERAND *op, int level);
+
+void print_value(EVAL_VALUE *v, int level) {
+       indent(level, 0);
+
+       switch(v->type) {
+               case EVAL_VALUE_INVALID:
+                       printf("VALUE (NOP)\n");
+                       break;
+
+               case EVAL_VALUE_NUMBER:
+                       printf("VALUE %Lf (NUMBER)\n", v->number);
+                       break;
+
+               case EVAL_VALUE_EXPRESSION:
+                       printf("VALUE (SUB-EXPRESSION)\n");
+                       print_operand(v->expression, level+1);
+                       break;
+
+               default:
+                       printf("VALUE (INVALID type %d)\n", v->type);
+                       break;
+
+       }
+}
+
+void print_operand(EVAL_OPERAND *op, int level) {
+
+//     if(op->operator != EVAL_OPERATOR_NOP) {
+               indent(level, 1);
+               if(op->operator) printf("%c (OPERATOR %d, prec: %d)\n", op->operator, op->id, op->precedence);
+               else printf("NOP (OPERATOR %d, prec: %d)\n", op->id, op->precedence);
+//     }
+
+       int i = op->count;
+       while(i--) print_value(&op->ops[i], level + 1);
+}
+
+calculated_number evaluate(EVAL_OPERAND *op);
+
+calculated_number evaluate_value(EVAL_VALUE *v) {
+       switch(v->type) {
+               case EVAL_VALUE_NUMBER:
+                       return v->number;
+
+               case EVAL_VALUE_EXPRESSION:
+                       return evaluate(v->expression);
+
+               default:
+                       fatal("I don't know how to handle EVAL_VALUE type %d", v->type);
+       }
+}
+
+calculated_number evaluate(EVAL_OPERAND *op) {
+       calculated_number n1, n2, r;
+
+       switch(op->operator) {
+               case EVAL_OPERATOR_SIGN_PLUS:
+                       r = evaluate_value(&op->ops[0]);
+                       break;
+
+               case EVAL_OPERATOR_SIGN_MINUS:
+                       r = -evaluate_value(&op->ops[0]);
+                       break;
+
+               case EVAL_OPERATOR_PLUS:
+                       if(op->count != 2)
+                               fatal("Operator '%c' requires 2 values, but we have %d", op->operator, op->count);
+                       n1 = evaluate_value(&op->ops[0]);
+                       n2 = evaluate_value(&op->ops[1]);
+                       r = n1 + n2;
+                       printf("%Lf = %Lf %c %Lf\n", r, n1, op->operator, n2);
+                       break;
+
+               case EVAL_OPERATOR_MINUS:
+                       if(op->count != 2)
+                               fatal("Operator '%c' requires 2 values, but we have %d", op->operator, op->count);
+                       n1 = evaluate_value(&op->ops[0]);
+                       n2 = evaluate_value(&op->ops[1]);
+                       r = n1 - n2;
+                       printf("%Lf = %Lf %c %Lf\n", r, n1, op->operator, n2);
+                       break;
+
+               case EVAL_OPERATOR_MULTIPLY:
+                       if(op->count != 2)
+                               fatal("Operator '%c' requires 2 values, but we have %d", op->operator, op->count);
+                       n1 = evaluate_value(&op->ops[0]);
+                       n2 = evaluate_value(&op->ops[1]);
+                       r = n1 * n2;
+                       printf("%Lf = %Lf %c %Lf\n", r, n1, op->operator, n2);
+                       break;
+
+               case EVAL_OPERATOR_DIVIDE:
+                       if(op->count != 2)
+                               fatal("Operator '%c' requires 2 values, but we have %d", op->operator, op->count);
+                       n1 = evaluate_value(&op->ops[0]);
+                       n2 = evaluate_value(&op->ops[1]);
+                       r = n1 / n2;
+                       printf("%Lf = %Lf %c %Lf\n", r, n1, op->operator, n2);
+                       break;
+
+               case EVAL_OPERATOR_EXPRESSION_OPEN:
+                       printf("BEGIN SUB-EXPRESSION\n");
+                       r = evaluate_value(&op->ops[0]);
+                       printf("END SUB-EXPRESSION\n");
+                       break;
+
+               case EVAL_OPERATOR_NOP:
+               case EVAL_OPERATOR_VALUE:
+                       r = evaluate_value(&op->ops[0]);
+                       break;
+
+               default:
+                       fatal("I don't know how to handle operator '%c'", op->operator);
+                       break;
+       }
+
+       return r;
+}
+
+void print_expression(EVAL_OPERAND *op, const char *failed_at, int error) {
+       if(op) {
+               printf("<expression root>\n");
+               print_operand(op, 0);
+               evaluate(op);
+               free_expression(op);
+       }
+       else {
+               printf("error: %d, failed_at: '%s'\n", error, (failed_at)?failed_at:"<NONE>");
+       }
+}
+
+
+int main(int argc, char **argv) {
+       if(argc != 2) {
+               fprintf(stderr, "I need an epxression\n");
+               exit(1);
+       }
+
+       const char *failed_at = NULL;
+       int error;
+       EVAL_OPERAND *op = parse_expression(argv[1], &failed_at, &error);
+       print_expression(op, failed_at, error);
+       return 0;
+}