Initial commit: daemon, clients, docs, Docker deploy pipelinev0.1.0

1 files changed, 43 insertions, 0 deletions

diff --git a/src/formula.h b/src/formula.h
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--- /dev/null
+++ b/src/formula.h
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+#ifndef BOKF_FORMULA_H
+#define BOKF_FORMULA_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/* Tiny, deterministic expression evaluator for voucher templates.
+   Grammar:  expr := term (('+'|'-') term)*
+             term := factor (('*'|'/') factor)*
+             factor := ('+'|'-') factor | primary
+             primary := number | 'x' | '(' expr ')'
+   Values are kronor as double; x is the template variable in kronor. */
+
+struct template_row {
+    const char *account;     /* account number */
+    const char *formula;
+    const char *description; /* optional */
+};
+
+struct resolved_row {
+    char account[16];
+    int64_t debit_ore;
+    int64_t credit_ore;
+    char description[128];
+};
+
+/* Returns 0 on success and stores the value in *out_kr. On error returns
+   -1 and writes a message to errbuf. */
+int formula_eval(const char *formula, double x, double *out_kr, char *errbuf,
+                 size_t errlen);
+
+/* Evaluates all rows with x, rounds to whole öre, drops zero rows, and
+   assigns the rounding remainder to the largest row so debit equals credit.
+   Returns 0 on success and sets *out_n. Errors (bad formula, too few
+   rows) are reported in errbuf. */
+int formula_resolve_rows(const struct template_row *rows, size_t nrows,
+                         double x, struct resolved_row *out, size_t *out_n,
+                         char *errbuf, size_t errlen);
+
+/* True when the formula parses (evaluated with x = 1). */
+int formula_valid(const char *formula);
+
+#endif