This commit is contained in:
Mattia Giambirtone 2022-06-22 11:44:03 +02:00
commit d61e9882b3
3 changed files with 96 additions and 86 deletions

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@ -73,7 +73,6 @@ proc `$`*(self: AstNode): string =
result = &"Identifier({self.name})"
proc initNodeVisitor*(): NodeVisitor =
## Initializes a node visitor
new(result)
@ -97,7 +96,8 @@ template ensureNonZero(node: AstNode) =
of NodeKind.Float, NodeKind.Integer:
raise newException(MathError, "value can't be zero")
else:
raise newException(CatchableError, &"invalid node kind '{node.kind}' for ensureNonZero")
raise newException(CatchableError,
&"invalid node kind '{node.kind}' for ensureNonZero")
template ensurePositive(node: AstNode) =
@ -107,7 +107,8 @@ template ensurePositive(node: AstNode) =
of NodeKind.Float, NodeKind.Integer:
raise newException(MathError, "value must be positive")
else:
raise newException(CatchableError, &"invalid node kind '{node.kind}' for ensureNonZero")
raise newException(CatchableError,
&"invalid node kind '{node.kind}' for ensureNonZero")
template ensureIntegers(left, right: AstNode) =
@ -126,11 +127,11 @@ template callFunction(fun: untyped, args: varargs[untyped]) =
# Forward declarations
proc visit_literal(self: NodeVisitor, node: AstNode): AstNode
proc visit_unary(self: NodeVisitor, node: AstNode): AstNode
proc visit_binary(self: NodeVisitor, node: AstNode): AstNode
proc visit_grouping(self: NodeVisitor, node: AstNode): AstNode
proc visit_call(self: NodeVisitor, node: AstNode): AstNode
proc visitLiteral(self: NodeVisitor, node: AstNode): AstNode
proc visitUnary(self: NodeVisitor, node: AstNode): AstNode
proc visitBinary(self: NodeVisitor, node: AstNode): AstNode
proc visitGrouping(self: NodeVisitor, node: AstNode): AstNode
proc visitCall(self: NodeVisitor, node: AstNode): AstNode
proc accept(self: AstNode, visitor: NodeVisitor): AstNode =
@ -138,15 +139,15 @@ proc accept(self: AstNode, visitor: NodeVisitor): AstNode =
## for our AST visitor
case self.kind:
of NodeKind.Integer, NodeKind.Float, NodeKind.Ident:
result = visitor.visit_literal(self)
result = visitor.visitLiteral(self)
of NodeKind.Binary:
result = visitor.visit_binary(self)
result = visitor.visitBinary(self)
of NodeKind.Unary:
result = visitor.visit_unary(self)
result = visitor.visitUnary(self)
of NodeKind.Grouping:
result = visitor.visit_grouping(self)
result = visitor.visitGrouping(self)
of NodeKind.Call:
result = visitor.visit_call(self)
result = visitor.visitCall(self)
proc eval*(self: NodeVisitor, node: AstNode): AstNode =
@ -154,12 +155,12 @@ proc eval*(self: NodeVisitor, node: AstNode): AstNode =
result = node.accept(self)
proc visit_literal(self: NodeVisitor, node: AstNode): AstNode =
proc visitLiteral(self: NodeVisitor, node: AstNode): AstNode =
## Visits a literal AST node (such as integers)
result = node # Not that we can do anything else after all, lol
proc visit_call(self: NodeVisitor, node: AstNode): AstNode =
proc visitCall(self: NodeVisitor, node: AstNode): AstNode =
## Visits function call expressions
case node.function.name:
of "sin":
@ -175,7 +176,8 @@ proc visit_call(self: NodeVisitor, node: AstNode): AstNode =
of "log":
let arg = self.eval(node.arguments[0])
ensureNonZero(arg)
callFunction(log, self.eval(node.arguments[0]).value, self.eval(node.arguments[1]).value)
callFunction(log, self.eval(node.arguments[0]).value, self.eval(
node.arguments[1]).value)
of "ln":
let arg = self.eval(node.arguments[0])
ensureNonZero(arg)
@ -209,10 +211,11 @@ proc visit_call(self: NodeVisitor, node: AstNode): AstNode =
of "arccosh":
callFunction(arccosh, self.eval(node.arguments[0]).value)
of "hypot":
callFunction(hypot, self.eval(node.arguments[0]).value, self.eval(node.arguments[1]).value)
callFunction(hypot, self.eval(node.arguments[0]).value, self.eval(
node.arguments[1]).value)
proc visit_grouping(self: NodeVisitor, node: AstNode): AstNode =
proc visitGrouping(self: NodeVisitor, node: AstNode): AstNode =
## Visits grouping (i.e. parenthesized) expressions. Parentheses
## have no other meaning than to allow a lower-precedence expression
## where a higher-precedence one is expected so that 2 * (3 + 1) is
@ -220,7 +223,7 @@ proc visit_grouping(self: NodeVisitor, node: AstNode): AstNode =
return self.eval(node.expr)
proc visit_binary(self: NodeVisitor, node: AstNode): AstNode =
proc visitBinary(self: NodeVisitor, node: AstNode): AstNode =
## Visits a binary AST node and evaluates it
let right = self.eval(node.right)
let left = self.eval(node.left)
@ -236,7 +239,8 @@ proc visit_binary(self: NodeVisitor, node: AstNode): AstNode =
# Modulo is a bit special since we must have integers
ensureIntegers(left, right)
ensureNonZero(right)
result = AstNode(kind: NodeKind.Integer, value: float(int(left.value) mod int(right.value)))
result = AstNode(kind: NodeKind.Integer, value: float(int(
left.value) mod int(right.value)))
of TokenType.Exp:
result = handleBinary(left, right, pow)
of TokenType.Mul:
@ -245,7 +249,7 @@ proc visit_binary(self: NodeVisitor, node: AstNode): AstNode =
discard # Unreachable
proc visit_unary(self: NodeVisitor, node: AstNode): AstNode =
proc visitUnary(self: NodeVisitor, node: AstNode): AstNode =
## Visits unary expressions and evaluates them
let expr = self.eval(node.operand)
case node.unOp.kind:

View File

@ -29,9 +29,9 @@ const tokens = to_table({
'*': TokenType.Mul, '/': TokenType.Div,
'%': TokenType.Modulo, '^': TokenType.Exp,
',': TokenType.Comma})
# All the identifiers and constants (such as PI)
# Since they're constant we don't even need to bother adding another
# AST node kind, we can just map the name to a float literal ;)
# All the identifiers and constants (such as PI)
# Since they're constant we don't even need to bother adding another
# AST node kind, we can just map the name to a float literal ;)
const constants = to_table({
"pi": Token(kind: TokenType.Float, lexeme: "3.141592653589793"),
"e": Token(kind: TokenType.Float, lexeme: "2.718281828459045"),

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@ -35,7 +35,8 @@ type
const arities = to_table({"sin": 1, "cos": 1, "tan": 1, "cosh": 1,
"tanh": 1, "sinh": 1, "arccos": 1, "arcsin": 1,
"arctan": 1, "log": 2, "log10": 1, "ln": 1, "log2": 1,
"hypot": 2, "sqrt": 1, "cbrt": 2, "arctanh": 1, "arcsinh": 1,
"hypot": 2, "sqrt": 1, "cbrt": 2, "arctanh": 1,
"arcsinh": 1,
"arccosh": 1
})
@ -160,7 +161,8 @@ proc call(self: Parser): AstNode =
arguments.add(self.binary())
while self.match(TokenType.Comma):
arguments.add(self.binary())
result = AstNode(kind: NodeKind.Call, arguments: arguments, function: expression)
result = AstNode(kind: NodeKind.Call, arguments: arguments,
function: expression)
if expression.kind != NodeKind.Ident:
self.error(&"can't call object of type {expression.kind}")
if len(arguments) != arities[expression.name]:
@ -175,7 +177,8 @@ proc unary(self: Parser): AstNode =
## Parses unary expressions such as -1
case self.step().kind:
of TokenType.Minus, TokenType.Plus:
result = AstNode(kind: NodeKind.Unary, unOp: self.previous(), operand: self.unary())
result = AstNode(kind: NodeKind.Unary, unOp: self.previous(),
operand: self.unary())
else:
result = self.call()
@ -186,7 +189,8 @@ proc pow(self: Parser): AstNode =
var operator: Token
while self.match(TokenType.Exp):
operator = self.previous()
result = AstNode(kind: NodeKind.Binary, left: result, right: self.unary(), binOp: operator)
result = AstNode(kind: NodeKind.Binary, left: result, right: self.unary(),
binOp: operator)
proc mul(self: Parser): AstNode =
@ -196,7 +200,8 @@ proc mul(self: Parser): AstNode =
var operator: Token
while self.match(TokenType.Div, TokenType.Modulo, TokenType.Mul):
operator = self.previous()
result = AstNode(kind: NodeKind.Binary, left: result, right: self.pow(), binOp: operator)
result = AstNode(kind: NodeKind.Binary, left: result, right: self.pow(),
binOp: operator)
proc addition(self: Parser): AstNode =
@ -205,7 +210,8 @@ proc addition(self: Parser): AstNode =
var operator: Token
while self.match(TokenType.Plus, TokenType.Minus):
operator = self.previous()
result = AstNode(kind: NodeKind.Binary, left: result, right: self.mul(), binOp: operator)
result = AstNode(kind: NodeKind.Binary, left: result, right: self.mul(),
binOp: operator)
proc binary(self: Parser): AstNode =