Add indentation engine and other fixes

include/editor/indents.h

@@ -0,0 +1,152 @@
+#ifndef EDITOR_INDENTS_H
+#define EDITOR_INDENTS_H
+
+#include "utils/utils.h"
+
+static const std::unordered_map<std::string, uint8_t> kLangtoIndent = {
+    {"make", 1}, {"yaml", 2}};
+
+// this indents the newline one level when the line (on the curser before \n  is
+// inserted) matches this at its end (stripped of whitespace)
+static const std::unordered_map<std::string, const std::vector<std::string>>
+    kLangtoBlockStartsEnd = {
+        {"bash", {"then", "do", "in", "{", "(", "\\", "&&", "||", "|"}},
+        {"c", {"{", "(", ":"}},
+        {"cpp", {"{", "(", ":"}},
+        {"h", {"{", "(", ":"}},
+        {"css", {"{", "("}},
+        {"fish", {"{", "(", "^", "&&", "||", "|"}},
+        {"go", {"{", "(", ":"}},
+        {"gomod", {"{", "(", ":"}},
+        {"haskell", {"do", "where", "then", "else", "of"}},
+        {"javascript", {"{", "(", "[", ":"}},
+        {"typescript", {"{", "(", "[", ":"}},
+        {"json", {"{", "[", ":"}},
+        {"jsonc", {"{", "[", ":"}},
+        {"ruby", {"then", "else", "begin", "{", "(", "["}},
+        {"lua", {"then", "do", "else", "repeat", "{", "(", "["}},
+        {"python", {":", "(", "[", "{"}},
+        {"rust", {"{", "(", "[", ":"}},
+        {"php", {"{", "(", "[", ":"}},
+        {"nginx", {"{"}},
+        {"yaml", {":"}},
+        {"sql", {"("}},
+        {"make", {":"}},
+        {"gdscript", {":", "(", "[", "{"}},
+};
+
+// this indents the newline one level when the line (on the curser before \n is
+// inserted) matches this at its start (stripped of whitespace)
+static const std::unordered_map<std::string, const std::vector<std::string>>
+    kLangtoBlockStartsStart = {
+        {"c", {"if", "for", "while"}},
+        {"cpp", {"if", "for", "while"}},
+        {"h", {"if", "for", "while"}},
+        {"fish", {"if", "else", "for", "while", "switch", "case", "function"}},
+        {"javascript", {"if", "for", "while"}},
+        {"typescript", {"if", "for", "while"}},
+        {"ruby",
+         {"if", "do", "when", "rescue", "class", "module", "def", "unless",
+          "until", "elsif", "ensure"}},
+        {"lua", {"function"}},
+        {"nginx", {"{"}},
+};
+
+// This dedents the line (under the cursor before \n is inserted) when the line
+// matches this fully (stripped of whitespace)
+static const std::unordered_map<std::string, const std::vector<std::string>>
+    kLangtoBlockEndsFull = {
+        {"bash", {"fi", "done", "esac", "}", ")"}},
+        {"c", {"}", ")"}},
+        {"cpp", {"}", ")"}},
+        {"h", {"}", ")"}},
+        {"css", {"}", ")"}},
+        {"fish", {"end"}},
+        {"go", {"}", ")"}},
+        {"gomod", {"}", ")"}},
+        {"javascript", {"}", ")", "]"}},
+        {"typescript", {"}", ")", "]"}},
+        {"json", {"}", "]"}},
+        {"jsonc", {"}", "]"}},
+        {"ruby", {"end", "else", "}", ")", "]"}},
+        {"lua", {"else", "}", ")", "]"}},
+        {"python", {"}", ")", "]", "else:"}},
+        {"rust", {"}", ")", "]"}},
+        {"php",
+         {"}", ")", "]", "else:", "endif;", "endfor;", "endwhile;",
+          "endswitch;", "endcase;", "endfunction;"}},
+        {"nginx", {"}"}},
+        {"sql", {")"}},
+        {"gdscript", {"}", ")", "]"}},
+};
+
+// This dedents the line (under the cursor before \n is inserted) when the line
+// matches this at its start (stripped of whitespace)
+static const std::unordered_map<std::string, const std::vector<std::string>>
+    kLangtoBlockEndsStart = {
+        {"c", {"case", "default:", "} else"}},
+        {"cpp", {"case", "default:", "} else"}},
+        {"h", {"case", "default:", "} else"}},
+        {"fish", {"else if"}},
+        {"go", {"case", "default:", "} else"}},
+        {"gomod", {"}", ")"}},
+        {"javascript", {"case", "default:"}},
+        {"typescript", {"case", "default:"}},
+        {"json", {"}", "]"}},
+        {"python", {"elif"}},
+        {"jsonc", {"}", "]"}},
+        {"ruby", {"when", "elsif", "rescue", "ensure"}},
+        {"lua", {"end", "elseif", "until"}},
+        {"rust", {"case", "default:", "} else"}},
+        {"php", {"case", "default:", "} else"}},
+};
+
+struct IndentationEngine {
+  // tabs = 1, spaces = 2+
+  uint8_t indent = 0;
+  struct Editor *editor = nullptr;
+
+  void compute_indent(Editor *n_editor);
+  void insert_new_line(Coord cursor);
+  void insert_tab(Coord cursor);
+  uint32_t set_indent(uint32_t row, int64_t indent_level);
+  uint32_t indent_line(uint32_t row);
+  uint32_t dedent_line(uint32_t row);
+  void indent_block(uint32_t start, uint32_t end);
+  void dedent_block(uint32_t start, uint32_t end);
+  // fixes a autocomplete block's indentation
+  char *block_to_asis(Coord cursor, std::string source, uint32_t *out_len);
+
+private:
+  // TODO: Ignore comments/strings too
+  // returns the indent level of the line itself or of the previous non-empty
+  uint32_t indent_expected(uint32_t row);
+  // returns the indent level of the line
+  uint32_t indent_real(char *line, uint32_t len);
+};
+
+inline static bool ends_with(const std::string &str,
+                             const std::string &suffix) {
+  const size_t str_len = str.size();
+  const size_t suf_len = suffix.size();
+  if (suf_len > str_len)
+    return false;
+  for (size_t i = 0; i < suf_len; i++)
+    if (str[str_len - suf_len + i] != suffix[i])
+      return false;
+  return true;
+}
+
+inline static bool starts_with(const std::string &str,
+                               const std::string &prefix) {
+  const size_t str_len = str.size();
+  const size_t pre_len = prefix.size();
+  if (pre_len > str_len)
+    return false;
+  for (size_t i = 0; i < pre_len; i++)
+    if (str[i] != prefix[i])
+      return false;
+  return true;
+}
+
+#endif