implement string escapes

src/index.ts

@@ -11,10 +11,8 @@ import { exec } from "child_process";
 
 const input = `
 function main() = (
-  print("uwu
+  print("\\3AAA\\n");
-");
+  print("meow\\n");
-  print("owo
-");
 );
 `;
 

src/lexer.ts

@@ -134,6 +134,7 @@ export function tokenize(input: string): Token[] {
           break;
         }
         case '"': {
+          const result = [];
           while (true) {
             const next = input[i + 1];
             span.end++;
@@ -141,11 +142,48 @@ export function tokenize(input: string): Token[] {
             if (next === '"') {
               break;
             }
+
+            if (next === "\\") {
+              span.end++;
+              i++;
+              switch (input[i]) {
+                case "\\":
+                  result.push("\\");
+                  break;
+                case '"':
+                  result.push('"');
+                  break;
+                case "n":
+                  result.push("\n");
+                  break;
+                case "r":
+                  result.push("\r");
+                  break;
+                case "t":
+                  result.push("\t");
+                  break;
+                case "a":
+                  result.push("\x07");
+                  break;
+                case "3":
+                  // device control 3 for callie's big project
+                  result.push("\x13");
+                  break;
+                default:
+                  throw new CompilerError(
+                    `invalid escape character: ${input[i]}`,
+                    { start: span.end - 1, end: span.end }
+                  );
+              }
+              continue;
+            }
+
+            result.push(next);
             if (next === undefined) {
               throw new CompilerError(`Unterminated string literal`, span);
             }
           }
-          const value = input.slice(span.start + 1, span.end - 1);
+          const value = result.join("");
           tokens.push({ kind: "lit_string", span, value });
           break;
         }

src/lower.ts

@@ -112,7 +112,9 @@ export function lower(ast: Ast): wasm.Module {
     }
   });
 
-  cx.reservedHeapMemoryStart = (mod.datas[0].init.length & ~0x8) + 0x8;
+  const HEAP_ALIGN = 0x08;
+  cx.reservedHeapMemoryStart =
+    (mod.datas[0].init.length + (HEAP_ALIGN - 1)) & ~(HEAP_ALIGN - 1);
 
   addRt(cx, ast);
 

src/wasm/wat.ts

@@ -138,8 +138,14 @@ function printString(s: string, f: Formatter) {
 function printBinaryString(buf: Uint8Array, f: Formatter) {
   const parts: string[] = [];
   for (let i = 0; i < buf.length; i++) {
-    const idx = buf[i];
+    const byte = buf[i];
-    parts.push(`\\${idx.toString(16).padStart(2, "0")}`);
+    const noEscape =
+      (byte > 0x30 && byte <= 0x5a) || (byte > 0x61 && byte <= 0x71);
+    if (noEscape) {
+      parts.push(`${String.fromCharCode(byte)}`);
+    } else {
+      parts.push(`\\${byte.toString(16).padStart(2, "0")}`);
+    }
   }
 
   f.word(`"${parts.join("")}"`);