Struct type (#25)

eventjet · Sep 2, 2024 · 5e2405f · 5e2405f
1 parent b6fba9e
commit 5e2405f
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Showing 20 changed files with 944 additions and 34 deletions.
diff --git a/composer.json b/composer.json
@@ -12,7 +12,7 @@
         "infection/infection": "^0.27.0",
         "maglnet/composer-require-checker": "^4.6",
         "phpstan/extension-installer": "^1.3",
-        "phpstan/phpstan": "^1.10.34",
+        "phpstan/phpstan": "^1.12",
         "phpstan/phpstan-phpunit": "^1.3",
         "phpstan/phpstan-strict-rules": "^1.5",
         "phpunit/phpunit": "^10.2",

diff --git a/src/Eq.php b/src/Eq.php
@@ -6,6 +6,10 @@
 
 use Eventjet\Ausdruck\Parser\Span;
 
+use function array_key_exists;
+use function count;
+use function get_object_vars;
+use function is_object;
 use function sprintf;
 
 /**
@@ -18,14 +22,41 @@ public function __construct(public readonly Expression $left, public readonly Ex
     {
     }
 
+    private static function compareStructs(object $left, object $right): bool
+    {
+        $leftVars = get_object_vars($left);
+        $rightVars = get_object_vars($right);
+        if (count($leftVars) !== count($rightVars)) {
+            return false;
+        }
+        /** @var mixed $value */
+        foreach ($leftVars as $key => $value) {
+            if (!array_key_exists($key, $rightVars)) {
+                return false;
+            }
+            if (!self::compareValues($value, $rightVars[$key])) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static function compareValues(mixed $left, mixed $right): bool
+    {
+        if (is_object($left) && is_object($right)) {
+            return self::compareStructs($left, $right);
+        }
+        return $left === $right;
+    }
+
     public function __toString(): string
     {
         return sprintf('%s === %s', $this->left, $this->right);
     }
 
     public function evaluate(Scope $scope): bool
     {
-        return $this->left->evaluate($scope) === $this->right->evaluate($scope);
+        return self::compareValues($this->left->evaluate($scope), $this->right->evaluate($scope));
     }
 
     public function equals(Expression $other): bool

diff --git a/src/Expr.php b/src/Expr.php
@@ -46,6 +46,14 @@ public static function listLiteral(array $elements, Span $location): ListLiteral
         return new ListLiteral($elements, $location);
     }
 
+    /**
+     * @param array<string, Expression> $fields
+     */
+    public static function structLiteral(array $fields, Span $location): StructLiteral
+    {
+        return new StructLiteral($fields, $location);
+    }
+
     /**
      * @param list<Expression> $arguments
      */
@@ -89,6 +97,11 @@ public static function negative(Expression $expression, Span|null $location = nu
         return new Negative($expression, $location ?? self::dummySpan());
     }
 
+    public static function fieldAccess(Expression $struct, string $field, Span $location): FieldAccess
+    {
+        return new FieldAccess($struct, $field, $location);
+    }
+
     private static function dummySpan(): Span
     {
         /** @infection-ignore-all These dummy spans are just there to fill parameter lists */

diff --git a/src/FieldAccess.php b/src/FieldAccess.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Eventjet\Ausdruck;
+
+use Eventjet\Ausdruck\Parser\Span;
+
+use function get_debug_type;
+use function is_object;
+use function property_exists;
+use function sprintf;
+
+/**
+ * @internal
+ * @psalm-internal Eventjet\Ausdruck
+ */
+final class FieldAccess extends Expression
+{
+    public function __construct(
+        public readonly Expression $struct,
+        public readonly string $field,
+        private readonly Span $location,
+    ) {
+    }
+
+    public function __toString(): string
+    {
+        return sprintf('%s.%s', $this->struct, $this->field);
+    }
+
+    public function location(): Span
+    {
+        return $this->location;
+    }
+
+    public function evaluate(Scope $scope): mixed
+    {
+        $struct = $this->struct->evaluate($scope);
+        if (!is_object($struct)) {
+            throw new EvaluationError(sprintf('Expected object, got %s', get_debug_type($struct)));
+        }
+        if (!property_exists($struct, $this->field)) {
+            throw new EvaluationError(sprintf('Unknown field "%s"', $this->field));
+        }
+        /** @phpstan-ignore-next-line property.dynamicName */
+        return $struct->{$this->field};
+    }
+
+    public function equals(Expression $other): bool
+    {
+        return $other instanceof self
+            && $this->struct->equals($other->struct)
+            && $this->field === $other->field;
+    }
+
+    public function getType(): Type
+    {
+        return $this->struct->getType()->fields[$this->field];
+    }
+}
diff --git a/src/Parser/Delimiters.php b/src/Parser/Delimiters.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Eventjet\Ausdruck\Parser;
+
+/**
+ * @psalm-internal Eventjet\Ausdruck\Parser
+ */
+enum Delimiters
+{
+    case CurlyBraces;
+    case AngleBrackets;
+
+    public function start(): string
+    {
+        return match ($this) {
+            self::CurlyBraces => '{ ',
+            self::AngleBrackets => '<',
+        };
+    }
+
+    public function end(): string
+    {
+        return match ($this) {
+            self::CurlyBraces => ' }',
+            self::AngleBrackets => '>',
+        };
+    }
+}
diff --git a/src/Parser/ExpressionParser.php b/src/Parser/ExpressionParser.php
@@ -7,10 +7,13 @@
 use Eventjet\Ausdruck\Call;
 use Eventjet\Ausdruck\Expr;
 use Eventjet\Ausdruck\Expression;
+use Eventjet\Ausdruck\FieldAccess;
 use Eventjet\Ausdruck\Get;
 use Eventjet\Ausdruck\ListLiteral;
+use Eventjet\Ausdruck\StructLiteral;
 use Eventjet\Ausdruck\Type;
 
+use function array_key_exists;
 use function array_shift;
 use function assert;
 use function count;
@@ -93,7 +96,7 @@ private static function parseLazy(Expression|null $left, Peekable $tokens, Decla
             if ($left === null) {
                 self::unexpectedToken($parsedToken);
             }
-            return self::call($left, $tokens, $declarations);
+            return self::dot($left, $tokens, $declarations);
         }
         if (is_string($token)) {
             if ($left !== null) {
@@ -184,6 +187,9 @@ private static function parseLazy(Expression|null $left, Peekable $tokens, Decla
         if ($token === Token::OpenBracket) {
             return self::parseListLiteral($tokens, $declarations);
         }
+        if ($token === Token::OpenBrace) {
+            return self::parseStructLiteral($tokens, $declarations);
+        }
         return null;
     }
 
@@ -367,18 +373,32 @@ private static function unexpectedToken(ParsedToken $token): never
         throw SyntaxError::create(sprintf('Unexpected %s', Token::print($token->token)), $token->location());
     }
 
+    /**
+     * @param Peekable<ParsedToken> $tokens
+     */
+    private static function dot(Expression $target, Peekable $tokens, Declarations $declarations): Call|FieldAccess
+    {
+        $dot = self::expect($tokens, Token::Dot);
+        [$name, $nameLocation] = self::expectIdentifier($tokens, $dot, 'function name');
+        $token = $tokens->peek()?->token;
+        return match ($token) {
+            Token::Colon, Token::OpenParen => self::call($name, $nameLocation, $target, $tokens, $declarations),
+            default => self::fieldAccess($target, $name, $target->location()->to($nameLocation)),
+        };
+    }
+
     /**
      * list<string>.some:bool(|item| item:string === needle:string)
      *             ================================================
      *
      * @param Peekable<ParsedToken> $tokens
      */
-    private static function call(Expression $target, Peekable $tokens, Declarations $declarations): Call
+    private static function call(string $name, Span $nameLocation, Expression $target, Peekable $tokens, Declarations $declarations): Call
     {
-        $dot = self::expect($tokens, Token::Dot);
-        [$name, $nameLocation] = self::expectIdentifier($tokens, $dot, 'function name');
         $fnType = $declarations->functions[$name] ?? null;
-        if ($tokens->peek()?->token === Token::Colon) {
+        $colonOrOpenParen = $tokens->peek();
+        assert($colonOrOpenParen !== null);
+        if ($colonOrOpenParen->token === Token::Colon) {
             $tokens->next();
             $typeNode = TypeParser::parse($tokens);
             if ($typeNode === null) {
@@ -463,6 +483,18 @@ private static function call(Expression $target, Peekable $tokens, Declarations
         return $target->call($name, $returnType, $args, $target->location()->to($closeParen->location()));
     }
 
+    private static function fieldAccess(Expression $target, string $name, Span $location): FieldAccess
+    {
+        $targetType = $target->getType();
+        if (!$targetType->isStruct()) {
+            throw TypeError::create(sprintf('Can\'t access field "%s" on non-struct type %s', $name, $targetType), $location);
+        }
+        if (!array_key_exists($name, $targetType->fields)) {
+            throw TypeError::create(sprintf('Unknown field "%s" on type %s', $name, $targetType), $location);
+        }
+        return Expr::fieldAccess($target, $name, $location);
+    }
+
     /**
      * @param Peekable<ParsedToken> $tokens
      * @return array{string, Span}
@@ -522,4 +554,49 @@ private static function parseListLiteral(Peekable $tokens, Declarations $declara
         $close = self::expect($tokens, Token::CloseBracket);
         return Expr::listLiteral($items, $start->location()->to($close->location()));
     }
+
+    /**
+     * @param Peekable<ParsedToken> $tokens
+     */
+    private static function parseStructLiteral(Peekable $tokens, Declarations $declarations): StructLiteral
+    {
+        $start = self::expect($tokens, Token::OpenBrace);
+        $fields = [];
+        while (true) {
+            $field = self::parseStructField($tokens, $declarations);
+            if ($field === null) {
+                break;
+            }
+            $fields[$field[0]] = $field[1];
+            $comma = $tokens->peek();
+            if ($comma?->token !== Token::Comma) {
+                break;
+            }
+            $tokens->next();
+        }
+        $close = self::expect($tokens, Token::CloseBrace);
+        return Expr::structLiteral($fields, $start->location()->to($close->location()));
+    }
+
+    /**
+     * @param Peekable<ParsedToken> $tokens
+     * @return array{string, Expression} | null
+     */
+    private static function parseStructField(Peekable $tokens, Declarations $declarations): array|null
+    {
+        $name = $tokens->peek();
+        if ($name === null) {
+            return null;
+        }
+        if (!is_string($name->token)) {
+            return null;
+        }
+        $tokens->next();
+        self::expect($tokens, Token::Colon);
+        $value = self::parseLazy(null, $tokens, $declarations);
+        if ($value === null) {
+            throw SyntaxError::create('Expected value after colon', self::nextSpan($tokens));
+        }
+        return [$name->token, $value];
+    }
 }
diff --git a/src/Parser/Token.php b/src/Parser/Token.php
@@ -19,6 +19,8 @@ enum Token: string
     case CloseBracket = ']';
     case OpenAngle = '<';
     case CloseAngle = '>';
+    case OpenBrace = '{';
+    case CloseBrace = '}';
     case Or = '||';
     case And = '&&';
     case Pipe = '|';

diff --git a/src/Parser/Tokenizer.php b/src/Parser/Tokenizer.php
@@ -7,6 +7,7 @@
 use function assert;
 use function ctype_space;
 use function is_numeric;
+use function ord;
 use function sprintf;
 use function str_contains;
 use function substr;
@@ -17,7 +18,13 @@
  */
 final class Tokenizer
 {
-    public const NON_IDENTIFIER_CHARS = '.[]()"=|<>{}:, -';
+    private const LOWER_A = 97;
+    private const LOWER_Z = 122;
+    private const UPPER_A = 65;
+    private const UPPER_Z = 90;
+    private const ZERO = 48;
+    private const NINE = 57;
+    private const UNDERSCORE = 95;
 
     /**
      * @param iterable<mixed, string> $chars
@@ -45,6 +52,8 @@ public static function tokenize(iterable $chars): iterable
                 ',' => Token::Comma,
                 '[' => Token::OpenBracket,
                 ']' => Token::CloseBracket,
+                '{' => Token::OpenBrace,
+                '}' => Token::CloseBrace,
                 default => null,
             };
             if ($singleCharToken !== null) {
@@ -107,7 +116,7 @@ public static function tokenize(iterable $chars): iterable
                 }
                 continue;
             }
-            if (!str_contains(self::NON_IDENTIFIER_CHARS, $char)) {
+            if (self::isIdentifierChar($char, first: true)) {
                 $startCol = $column;
                 yield new ParsedToken(self::identifier($chars, $line, $column), $line, $startCol);
                 continue;
@@ -132,7 +141,9 @@ private static function identifier(Peekable $chars, int $line, int &$column): st
                 break;
             }
 
-            if (ctype_space($char) || str_contains(self::NON_IDENTIFIER_CHARS, $char)) {
+            // No idea why it works if "first" is always false, but it
+            // does, The error is probably caught somewhere else.
+            if (ctype_space($char) || !self::isIdentifierChar($char, first: false)) {
                 break;
             }
 
@@ -244,4 +255,16 @@ private static function string(Peekable $chars, int $line, int &$column): Litera
         }
         return new Literal($string);
     }
+
+    private static function isIdentifierChar(string $char, bool $first): bool
+    {
+        $byte = ord($char);
+        $isChar = ($byte >= self::LOWER_A && $byte <= self::LOWER_Z) || ($byte >= self::UPPER_A && $byte <= self::UPPER_Z);
+        if ($first) {
+            return $isChar;
+        }
+        return $isChar
+            || ($byte >= self::ZERO && $byte <= self::NINE)
+            || $byte === self::UNDERSCORE;
+    }
 }