Fixes in code

compiler/chapter_3.md

@@ -365,7 +365,7 @@ class Parser {
             if (this.test("[")) {
                 this.step();
                 const value = this.parseExpr();
-                if (!this.test("]") {
+                if (!this.test("]")) {
                     this.report("expected ']'");
                     return this.expr({ type: "error" }, pos);
                 }
@@ -405,7 +405,7 @@ class Parser {
             if (this.test("(")) {
                 this.step();
                 let args: Expr[] = [];
-                if (!this.test(")") {
+                if (!this.test(")")) {
                     args.push(this.parseExpr());
                     while (this.test(",")) {
                         this.step();
@@ -414,7 +414,6 @@ class Parser {
                         args.push(this.parseExpr());
                     }
                 }
-                const value = this.parseExpr();
                 if (!this.test(")") {
                     this.report("expected ')'");
                     return this.expr({ type: "error" }, pos);
@@ -642,7 +641,7 @@ class Parser {
     public parseBreak(): Stmt {
         const pos = this.pos();
         this.step();
-        if (!this.test(";")) {
+        if (this.test(";")) {
             return this.stmt({ type: "break" }, pos);
         }
         const expr = this.parseExpr();
@@ -672,7 +671,7 @@ class Parser {
     public parseReturn(): Stmt {
         const pos = this.pos();
         this.step();
-        if (!this.test(";")) {
+        if (this.test(";")) {
             return this.stmt({ type: "return" }, pos);
         }
         const expr = this.parseExpr();
@@ -781,7 +780,7 @@ class Parser {
     public parseParam(): { ok: true, value: Param } | { ok: false } {
         const pos = this.pos();
         if (this.test("ident")) {
-            const ident = this.current().value;
+            const ident = this.current().identValue!;
             this.step();
             return { ok: true, value: { ident, pos } };
         }
@@ -913,6 +912,7 @@ class Parser {
         // ...
         while (!this.done()) {
             if (this.test("}")) {
+                this.step();
                 return this.expr({ type: "block", stmts }, pos);
             // ...
             }
@@ -1042,8 +1042,10 @@ class Parser {
                     this.eatSemicolon();
                     stmts.push(this.stmt({ type: "assign", subject: expr, value }, pos));
                 } else if (this.test(";")) {
+                    this.step();
                     stmts.push(this.stmt({ type: "expr", expr }, expr.pos));
                 } else if (this.test("}")) {
+                    this.step();
                     return this.expr({ type: "block", stmts, expr }, pos);
                 } else {
                     this.report("expected ';' or '}'");
@@ -1129,7 +1131,7 @@ class Parser {
             if (this.test("fn")) {
             // ...
             } else if (this.test("{") || this.test("if") || this.test("loop")) {
-                let expr = this.parseMultiLineBlockExpr();
+                const expr = this.parseMultiLineBlockExpr();
                 stmts.push(this.stmt({ type: "expr", expr }, expr.pos));
             // ...
             }
@@ -1152,6 +1154,7 @@ class Parser {
             // ...
             } else  {
                 stmts.push(this.parseAssign());
+                this.eatSemicolon();
             }
         }
         return stmts;

compiler/chapter_4.md

@@ -290,7 +290,7 @@ Let's make a function `evalExpr` for evaluating expressions.
 ```ts
 class Evaluator {
     // ...
-    public evalExpr(expr: Expr, syms: Expr): Flow {
+    public evalExpr(expr: Expr, syms: Syms): Flow {
         if (expr.kind.type === "error") {
             throw new Error("error in AST");
         }
@@ -785,7 +785,7 @@ class Evaluator {
                 sym.value = value;
                 return flowValue({ type: "null" });
             }
-            if (stmt.kind.subject.type === "field") {
+            if (stmt.kind.subject.kind.type === "field") {
                 const [subject, subjectFlow] = expectValue(this.evalExpr(stmt.kind.subject.kind.subject, syms));
                 if (!subject)
                     return subjectFlow;
@@ -906,8 +906,8 @@ We'll want a function for evaluating the top-level statements.
 ```ts
 class Evaluator {
     // ...
-    public evalStmts(stmts: Stmt[], syms: Syms) {
+    public evalStmts(stmts: Stmt[]) {
-        let scopeSyms = new Syms(syms);
+        let scopeSyms = new Syms(this.root);
         for (const stmt of stmts) {
             const flow = this.evalStmt(stmt, scopeSyms);
             if (flow.type !== "value")

compiler/chapter_5.md

@@ -77,15 +77,15 @@ Exactly like in chapter 1, we need a function for evaluating the expression stru
 
 ```rs
 fn eval_expr(node) {
-    if (node.type == "int") {
+    if == node.type "int" {
         return node.value;
     }
-    if (node.type == "add") {
+    if == node.type "add" {
         let left = eval_expr(node.left);
         let right = eval_expr(node.right);
         return + left right;
     }
-    if (node.type == "multiply") {
+    if == node.type "multiply" {
         let left = eval_expr(node.left);
         let right = eval_expr(node.right);
         return * left right;
@@ -150,12 +150,12 @@ fn lex(text) {
         } else if == text[i] "+"[0] {
             i = + i 1;
             let token = struct();
-            token["type"] = "+"[0];
+            token["type"] = "+";
             array_push(token);
         } else if == text[i] "*"[0] {
             i = + i 1;
             let token = struct();
-            token["type"] = "*"[0];
+            token["type"] = "*";
             array_push(token);
         } else {
             println("illegal character");