add PlusEqual and MinusEqual for variable assignment

This commit is contained in:
Luna 2019-08-27 11:25:04 -03:00
parent c63b42c414
commit 8007f9e860
2 changed files with 49 additions and 7 deletions

View file

@ -55,6 +55,7 @@ fn main(a int) int {
str := 'hello'
len := str.len
str.len = str.len + 1
x += 1
// str.len += 1
}

View file

@ -688,7 +688,7 @@ pub const Parser = struct {
fn parseAssignment(self: *@This()) anyerror!*Expr {
// there can be two assignments coming out of this function:
// - a mutable/immutable variable declaration with :=
// - an assignment to a variable with =
// - an assignment to a variable with =, +=, -=
// one is a statement, other is an expression. since the normal result
// of this is an Expr, we wrap variable assignments in an Expr as well.
@ -701,7 +701,9 @@ pub const Parser = struct {
var expr = try self.parseOr();
if (self.check(.ColonEqual) or self.check(.Equal)) {
if (self.compareAnyOf(&[_]TokenType{
.ColonEqual, .Equal, .PlusEqual, .MinusEqual,
})) {
return try self.finishAssignment(expr, mutable);
}
@ -713,22 +715,61 @@ pub const Parser = struct {
_ = try self.nextToken();
var value = try self.parseAssignment();
// TODO convert binary's op field from Token to
// something else, maybe enum'd
switch (expr.*) {
.Variable => {
switch (op.ttype) {
.ColonEqual => return try self.mkVarDecl(expr.Variable, value, mutable),
.Equal => return try self.mkAssign(expr.Variable, value),
.PlusEqual => {
var plus_op = try self.mkToken(.Plus, "+", op.line);
return try self.mkAssign(
expr.Variable,
try self.mkBinary(expr, plus_op, value),
);
},
.MinusEqual => {
var new_op = try self.mkToken(.Minus, "-", op.line);
return try self.mkAssign(
expr.Variable,
try self.mkBinary(expr, new_op, value),
);
},
else => unreachable,
}
},
.Get => |get| {
if (op.ttype == .ColonEqual) {
switch (op.ttype) {
.ColonEqual => {
self.doError("can not initialize struct field");
return Result.CompileError;
}
},
return try self.mkSet(get.struc, get.name, value);
//.PlusEqual => {
// var plus_op = try self.mkToken(.Plus, "+", op.line);
// return try self.mkAssign(
// expr.Variable,
// try self.mkBinary(expr, plus_op, value),
// );
//},
//.MinusEqual => {
// var new_op = try self.mkToken(.Minus, "-", op.line);
// return try self.mkSet(
// get.struc, get.name,
// try self.mkBinary(expr, new_op, value),
// );
//},
.Equal => return try self.mkSet(get.struc, get.name, value),
else => unreachable,
}
},
else => |expr_typ| {