1 files changed, 68 insertions, 0 deletions
diff --git a/prism/internal/integer.h b/prism/internal/integer.h
new file mode 100644
index 0000000000..7c9767e323
--- /dev/null
+++ b/prism/internal/integer.h
@@ -0,0 +1,68 @@
+/*
+ * This module provides functions for working with arbitrary-sized integers.
+ */
+#ifndef PRISM_INTERNAL_INTEGER_H
+#define PRISM_INTERNAL_INTEGER_H
+
+#include "prism/buffer.h"
+#include "prism/integer.h"
+
+#include <stdint.h>
+
+/*
+ * An enum controlling the base of an integer. It is expected that the base is
+ * already known before parsing the integer, even though it could be derived
+ * from the string itself.
+ */
+typedef enum {
+    /* The default decimal base, with no prefix. Leading 0s will be ignored. */
+    PM_INTEGER_BASE_DEFAULT,
+
+    /* The binary base, indicated by a 0b or 0B prefix. */
+    PM_INTEGER_BASE_BINARY,
+
+    /* The octal base, indicated by a 0, 0o, or 0O prefix. */
+    PM_INTEGER_BASE_OCTAL,
+
+    /* The decimal base, indicated by a 0d, 0D, or empty prefix. */
+    PM_INTEGER_BASE_DECIMAL,
+
+    /* The hexadecimal base, indicated by a 0x or 0X prefix. */
+    PM_INTEGER_BASE_HEXADECIMAL,
+
+    /*
+     * An unknown base, in which case pm_integer_parse will derive it based on
+     * the content of the string. This is less efficient and does more
+     * comparisons, so if callers know the base ahead of time, they should use
+     * that instead.
+     */
+    PM_INTEGER_BASE_UNKNOWN
+} pm_integer_base_t;
+
+/*
+ * Parse an integer from a string. This assumes that the format of the integer
+ * has already been validated, as internal validation checks are not performed
+ * here.
+ */
+void pm_integer_parse(pm_integer_t *integer, pm_integer_base_t base, const uint8_t *start, const uint8_t *end);
+
+/*
+ * Compare two integers. This function returns -1 if the left integer is less
+ * than the right integer, 0 if they are equal, and 1 if the left integer is
+ * greater than the right integer.
+ */
+int pm_integer_compare(const pm_integer_t *left, const pm_integer_t *right);
+
+/*
+ * Reduce a ratio of integers to its simplest form.
+ *
+ * If either the numerator or denominator do not fit into a 32-bit integer, then
+ * this function is a no-op. In the future, we may consider reducing even the
+ * larger numbers, but for now we're going to keep it simple.
+ */
+void pm_integers_reduce(pm_integer_t *numerator, pm_integer_t *denominator);
+
+/* Convert an integer to a decimal string. */
+void pm_integer_string(pm_buffer_t *buffer, const pm_integer_t *integer);
+
+#endif