Split out number parsing

1 files changed, 83 insertions, 0 deletions

diff --git a/src/parse/numbers.c b/src/parse/numbers.c
new file mode 100644
index 00000000..a0db1273
--- /dev/null
+++ b/src/parse/numbers.c
@@ -0,0 +1,83 @@
+
+#include <ctype.h>
+#include <gc.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <unictype.h>
+#include <uniname.h>
+
+#include "../ast.h"
+#include "../stdlib/util.h"
+#include "context.h"
+#include "errors.h"
+#include "utils.h"
+
+static const double RADIANS_PER_DEGREE = 0.0174532925199432957692369076848861271344287188854172545609719144;
+
+public
+ast_t *parse_int(parse_ctx_t *ctx, const char *pos) {
+    const char *start = pos;
+    (void)match(&pos, "-");
+    if (!isdigit(*pos)) return NULL;
+    if (match(&pos, "0x")) { // Hex
+        pos += strspn(pos, "0123456789abcdefABCDEF_");
+    } else if (match(&pos, "0b")) { // Binary
+        pos += strspn(pos, "01_");
+    } else if (match(&pos, "0o")) { // Octal
+        pos += strspn(pos, "01234567_");
+    } else { // Decimal
+        pos += strspn(pos, "0123456789_");
+    }
+    char *str = GC_MALLOC_ATOMIC((size_t)(pos - start) + 1);
+    memset(str, 0, (size_t)(pos - start) + 1);
+    for (char *src = (char *)start, *dest = str; src < pos; ++src) {
+        if (*src != '_') *(dest++) = *src;
+    }
+
+    if (match(&pos, "e") || match(&pos, "f")) // floating point literal
+        return NULL;
+
+    if (match(&pos, "%")) {
+        double n = strtod(str, NULL) / 100.;
+        return NewAST(ctx->file, start, pos, Num, .n = n);
+    } else if (match(&pos, "deg")) {
+        double n = strtod(str, NULL) * RADIANS_PER_DEGREE;
+        return NewAST(ctx->file, start, pos, Num, .n = n);
+    }
+
+    return NewAST(ctx->file, start, pos, Int, .str = str);
+}
+
+public
+ast_t *parse_num(parse_ctx_t *ctx, const char *pos) {
+    const char *start = pos;
+    bool negative = match(&pos, "-");
+    if (!isdigit(*pos) && *pos != '.') return NULL;
+    else if (*pos == '.' && !isdigit(pos[1])) return NULL;
+
+    size_t len = strspn(pos, "0123456789_");
+    if (strncmp(pos + len, "..", 2) == 0) return NULL;
+    else if (pos[len] == '.') len += 1 + strspn(pos + len + 1, "0123456789");
+    else if (pos[len] != 'e' && pos[len] != 'f' && pos[len] != '%') return NULL;
+    if (pos[len] == 'e') {
+        len += 1;
+        if (pos[len] == '-') len += 1;
+        len += strspn(pos + len, "0123456789_");
+    }
+    char *buf = GC_MALLOC_ATOMIC(len + 1);
+    memset(buf, 0, len + 1);
+    for (char *src = (char *)pos, *dest = buf; src < pos + len; ++src) {
+        if (*src != '_') *(dest++) = *src;
+    }
+    double d = strtod(buf, NULL);
+    pos += len;
+
+    if (negative) d *= -1;
+
+    if (match(&pos, "%")) d /= 100.;
+    else if (match(&pos, "deg")) d *= RADIANS_PER_DEGREE;
+
+    return NewAST(ctx->file, start, pos, Num, .n = d);
+}