samples: fix sample parsers and align their documented grammars

samples/CalcExpr/ExpressionParser.cs

@@ -35,12 +35,12 @@ private static Parser<double> CreateExpressionParser()
             ).Do((u, _, d) => u.HasValue ? -d : d);
 
         var mul_expr =
-            unary_expr.Fold(
+            unary_expr.FoldL(
                 OneOf("*/").ThenIgnore(S),
                 (l, r, o) => o == '*' ? l * r : l / r);
 
         sum_expr.Parser =
-            mul_expr.Fold(
+            mul_expr.FoldL(
                 OneOf("+-").ThenIgnore(S),
                 (l, r, o) => o == '+' ? l + r : l - r);
 

samples/CalcExpr/README.md

@@ -4,37 +4,41 @@ This project implements a simple mathematical expression parser.
 
 ## Simple Expression Grammar
 
-```sh
+```text
 start
   = S sum_expr EOF
   ;
 
 sum_expr
-  = mul_expr (S [+-] mul_expr)*
+  = mul_expr ([+-] S mul_expr)*
   ;
 
 mul_expr
-  = unary_expr (S [*/] unary_expr)*
+  = unary_expr ([*/] S unary_expr)*
   ;
 
 unary_expr
-  = S "-"? primary_expr
+  = "-"? S primary_expr
   ;
 
 primary_expr
   = parenthesis_expr / number_expr
   ;
 
 parenthesis_expr
-  = S "(" Sum S ")"
+  = "(" S sum_expr ")" S
   ;
 
 number_expr
-  =  S [0-9]+
+  = number S
+  ;
+
+number
+  = [+-]? [0-9]+ ("." [0-9]+)? ([eE] [+-]? [0-9]+)?
   ;
 
 S
-  = [ \t\r\n]*
+  = [\s]*
   ;
 
 EOF

samples/Json/JsonParser.cs

@@ -55,6 +55,6 @@ public static class JsonParser
                 @object
                 ).ThenIgnore(S);
 
-        return S.Then(value);
+        return value.Between(S, Eof);
     }
 }

samples/Json/README.md

@@ -2,11 +2,9 @@
 
 This project implements a simple JSON parser.
 
-## JSON Grammar
-
-```sh
+```text
 start
-  = value $
+  = S value $
   ;
 
 value
@@ -18,14 +16,14 @@ object
   ;
 
 member
-  = string ":" S value
+  = string S ":" S value
   ;
 
 array
   = "[" S (value ("," S value)*)? "]" S
   ;
 
 S
-  = [ \t\r\n]*
+  = [\s]*
   ;
 ```

samples/TinyC/Node.cs

@@ -14,6 +14,7 @@ public abstract record Node
     public static Node Unary(char op, Node operand) => new UnaryNode(op, operand);
     public static Node Binary(string op, Node left, Node right) => new BinaryNode(op, left, right);
     public static Node Assign(Node variable, Node value) => Binary("=", variable, value);
+    public static Node ExpressionStatement(Node expression) => new ExpressionStatementNode(expression);
     public static Node Block(IReadOnlyList<Node> statements) => new BlockNode(statements);
     public static Node Block(Node statement) => statement is BlockNode ? statement : new BlockNode([statement]);
 
@@ -57,6 +58,7 @@ static void Print(Node node, IndentedStringBuilder sb)
                     break;
 
                 case TernaryNode c:
+                    sb.Append('(');
                     Print(c.Test, sb);
                     sb.IncrementIndent();
                     sb
@@ -68,6 +70,7 @@ static void Print(Node node, IndentedStringBuilder sb)
                         .AppendLine()
                         .Append(": ");
                     Print(c.IfFalse, sb);
+                    sb.Append(')');
                     sb.DecrementIndent();
                     break;
 
@@ -95,8 +98,9 @@ static void Print(Node node, IndentedStringBuilder sb)
                     break;
 
                 case BinaryNode(Operator: "=", var variable, var expr):
+                    sb.Append('(');
                     Print(variable, sb);
-                    sb.Append(" = (");
+                    sb.Append(" = ");
                     Print(expr, sb);
                     sb.Append(')');
                     break;
@@ -109,16 +113,17 @@ static void Print(Node node, IndentedStringBuilder sb)
                     sb.Append(')');
                     break;
 
+                case ExpressionStatementNode statement:
+                    Print(statement.Expression, sb);
+                    sb.AppendLine(";");
+                    break;
+
                 case BlockNode block:
                     sb.AppendLine("{");
                     sb.IncrementIndent();
 
                     foreach (var stmt in block.Statements)
-                    {
                         Print(stmt, sb);
-                        if (stmt is NumberNode or VariableNode or UnaryNode or BinaryNode)
-                            sb.AppendLine(";");
-                    }
 
                     sb.DecrementIndent();
                     sb.AppendLine("}");
@@ -135,5 +140,6 @@ public sealed record WhileLoopNode(Node Test, Node Body) : Node;
     public sealed record DoWhileLoopNode(Node Test, Node Body) : Node;
     public sealed record UnaryNode(char Operator, Node Operand) : Node;
     public sealed record BinaryNode(string Operator, Node Left, Node Right) : Node;
+    public sealed record ExpressionStatementNode(Node Expression) : Node;
     public sealed record BlockNode(IReadOnlyList<Node> Statements) : Node;
 }

samples/TinyC/README.md

@@ -1,34 +1,66 @@
 # Tiny-C
 
-This project implements a parser for the [Tiny-C](http://www.iro.umontreal.ca/~felipe/IFT2030-Automne2002/Complements/tinyc.c) language, a highly simplified version of `C` designed as an educational tool for learning about compilers.
-
-All variables are predefined, of integer type, and initialized to zero.
+This project implements a parser for the [Tiny-C](http://www.iro.umontreal.ca/~felipe/IFT2030-Automne2002/Complements/tinyc.c) language,
+a highly simplified version of `C` designed as an educational tool for learning about compilers.
 
 The main differences from the original `Tiny-C` are:
 - Variable names are not limited to single letters.
 - Additional operators are supported.
+- Line comments (`// ...`) and block comments (`/* ... */`) are supported.
 
 ## Tiny-C Grammar
 
-```sh
+```
 start
   = S statement EOF
   ;
 
 keyword
-  = ("while" / "do" / "if" / "else") ![\w]
+  = while_keyword / do_keyword / if_keyword / else_keyword
+  ;
+
+identifier_part
+  = [a-zA-Z_0-9]
+  ;
+
+while_keyword
+  = "while" !identifier_part
+  ;
+
+do_keyword
+  = "do" !identifier_part
+  ;
+
+if_keyword
+  = "if" !identifier_part
+  ;
+
+else_keyword
+  = "else" !identifier_part
   ;
 
 number
   = [0-9]+
   ;
 
 variable
-  = !keyword [a-zA-Z_][a-zA-Z0-9_]*
+  = !keyword [a-z] identifier_part*
   ;
 
 S
-  = [ \t\n\r]*
+  = (single_comment / multiline_comment / [\s])*
+  ;
+
+single_comment
+  = "//" (!EOL .)* EOL
+  ;
+
+multiline_comment
+  = "/*" (!"*/" .)* "*/"
+  ;
+
+EOL
+  = "\r\n" / [\r\n\u0085\u2028\u2029] / EOF
   ;
 
 EOF
@@ -44,11 +76,11 @@ number_expr
   ;
 
 expr
-  = assigment_expr
+  = assignment_expr
   / ternary_expr
   ;
 
-assigment_expr
+assignment_expr
   = var_expr "=" S expr
   ;
 
@@ -81,7 +113,7 @@ eq_expr
   ;
 
 relational_expr
-  = shift_expr (("<" / "<=" / ">" / ">=") S shift_expr)*
+  = shift_expr (("<=" / "<" / ">=" / ">") S shift_expr)*
   ;
 
 shift_expr
@@ -120,15 +152,15 @@ statement
   ;
 
 if_statement
-  = "if" S "(" S expr ")" S statement ("else" S statement)?
+  = if_keyword S "(" S expr ")" S statement (else_keyword S statement)?
   ;
 
 while_statement
-  = "while" S "(" S expr ")" S statement
+  = while_keyword S "(" S expr ")" S statement
   ;
 
 do_while_statement
-  = "do" S statement "while" S "(" S expr ")" S ";" S
+  = do_keyword S statement while_keyword S "(" S expr ")" S ";" S
   ;
 
 block_statement