ooh okay diva

next/core/lexer.c

@@ -0,0 +1,155 @@
+#include <ctype.h>
+#include <growl.h>
+#include <stdlib.h>
+
+static int lexer_getc(GrowlLexer *lx) {
+  int c = getc(lx->file);
+  if (c == '\n') {
+    lx->current_row++;
+    lx->current_col = 0;
+  } else if (c != EOF) {
+    lx->current_col++;
+  }
+  return c;
+}
+
+static void lexer_ungetc(GrowlLexer *lx, int c) {
+  ungetc(c, lx->file);
+  if (c == '\n') {
+    lx->current_row--;
+  } else if (c != EOF) {
+    lx->current_col--;
+  }
+}
+
+static int getc_ws(GrowlLexer *lx) {
+  if (feof(lx->file))
+    return EOF;
+  for (;;) {
+    int ch = lexer_getc(lx);
+    if (isspace(ch))
+      continue;
+    return ch;
+  }
+}
+
+static int is_delimiter(int i) {
+  return i == '(' || i == ')' || i == '[' || i == ']' || i == '{' || i == '}' ||
+         i == ';' || i == '\\' || i == '"';
+}
+
+static void append(GrowlLexer *lexer, int ch) {
+  if (lexer->cursor >= GROWL_LEXER_BUFSIZE) {
+    fprintf(stderr, "lexer: buffer overflow\n");
+    abort();
+  }
+  lexer->buffer[lexer->cursor++] = (char)(ch & 0xff);
+}
+
+static int scan_word(GrowlLexer *lx) {
+  int next = lexer_getc(lx);
+  for (;;) {
+    if (next == -1) {
+      if (lx->cursor == 0)
+        lx->kind = GTOK_EOF;
+      append(lx, 0);
+      return lx->kind;
+    }
+    if (is_delimiter(next) || isspace(next)) {
+      lexer_ungetc(lx, next);
+      append(lx, 0);
+      return lx->kind;
+    }
+    append(lx, next);
+    next = lexer_getc(lx);
+  }
+}
+
+static int scan_string(GrowlLexer *lexer) {
+  int next;
+  for (;;) {
+    next = lexer_getc(lexer);
+    switch (next) {
+    case EOF:
+      goto eof;
+    case '\\':
+      // TODO: \x escape sequences
+      next = lexer_getc(lexer);
+      if (next == -1)
+        goto eof;
+      switch (next) {
+      case 't':
+        append(lexer, '\t');
+        break;
+      case 'n':
+        append(lexer, '\n');
+        break;
+      case 'r':
+        append(lexer, '\r');
+        break;
+      case 'b':
+        append(lexer, '\b');
+        break;
+      case 'v':
+        append(lexer, '\v');
+        break;
+      case 'f':
+        append(lexer, '\f');
+        break;
+      case '0':
+        append(lexer, '\0');
+        break;
+      case 'e':
+        append(lexer, '\x1b');
+        break;
+      case '\\':
+      case '"':
+        append(lexer, next);
+        break;
+      default:
+        return lexer->kind = GTOK_INVALID;
+      }
+      break;
+    case '"':
+      append(lexer, 0);
+      return lexer->kind = GTOK_STRING;
+    default:
+      append(lexer, next);
+    }
+  }
+
+eof:
+  return lexer->kind = GTOK_INVALID;
+}
+
+int growl_lexer_next(GrowlLexer *lexer) {
+  lexer->cursor = 0;
+  if (feof(lexer->file)) {
+    return lexer->kind = GTOK_EOF;
+  }
+
+  int next = getc_ws(lexer);
+  lexer->start_row = lexer->current_row;
+  lexer->start_col = lexer->current_col ? lexer->current_col - 1 : 0;
+
+  switch (next) {
+  case '\\':
+    for (; next != '\n'; next = getc_ws(lexer))
+      ;
+    return growl_lexer_next(lexer);
+  case '(':
+  case ')':
+  case '[':
+  case ']':
+  case '{':
+  case '}':
+  case ';':
+    return lexer->kind = next;
+  case '"':
+    return scan_string(lexer);
+  default:
+    lexer_ungetc(lexer, next);
+    lexer->kind = GTOK_WORD;
+    return scan_word(lexer);
+  }
+}