better typing for tokens (#49)

wcho21 · Jan 24, 2024 · 1e0b789 · 1e0b789
1 parent d035838
commit 1e0b789
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Showing 17 changed files with 691 additions and 287 deletions.
diff --git a/src/lexer/char-buffer/char-reader/index.ts b/src/lexer/char-buffer/char-reader/index.ts
@@ -20,33 +20,7 @@ export default class CharReader {
     this.col = 0;
   }
 
-  private peekNewLine(): string | null {
-    // return if end of input
-    if (this.index === this.chars.length) {
-      return null;
-    }
-
-    // return if no new line
-    const char = this.chars[this.index];
-    if (char !== "\r" && char !== "\n") {
-      return null;
-    }
-
-    // return if the last character
-    if (this.index+1 === this.chars.length) {
-      return char;
-    }
-
-    // return if single-character new line
-    const nextChar = this.chars[this.index+1];
-    if (nextChar !== "\r" && nextChar !== "\n") {
-      return char;
-    }
-
-    // return two-character new line
-    return char + nextChar;
-  }
-
+  /** return character at current position */
   readChar(): SourceChar {
     // return fallback character if end of input
     if (this.index === this.chars.length) {
@@ -85,6 +59,7 @@ export default class CharReader {
     return sourceChar;
   }
 
+  /** advance to next character */
   advance(): void {
     if (this.index === this.chars.length) {
       return;
@@ -104,6 +79,33 @@ export default class CharReader {
     ++this.col;
   }
 
+  private peekNewLine(): string | null {
+    // return if end of input
+    if (this.index === this.chars.length) {
+      return null;
+    }
+
+    // return if no new line
+    const char = this.chars[this.index];
+    if (char !== "\r" && char !== "\n") {
+      return null;
+    }
+
+    // return if the last character
+    if (this.index+1 === this.chars.length) {
+      return char;
+    }
+
+    // return if single-character new line
+    const nextChar = this.chars[this.index+1];
+    if (nextChar !== "\r" && nextChar !== "\n") {
+      return char;
+    }
+
+    // return two-character new line
+    return char + nextChar;
+  }
+
   /** @deprecated Returns current character; if end of input, return fallback character */
   read(): string {
     if (this.index === this.chars.length) {