1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
//! The syntax tree.
use std::fmt::{self, Debug, Formatter};
use crate::color::RgbaColor;
use crate::compute::table::{SpannedEntry, Table};
use crate::compute::value::{TableValue, Value};
use crate::layout::LayoutContext;
use crate::length::Length;
use crate::{DynFuture, Feedback};
use super::decoration::Decoration;
use super::span::{Spanned, SpanVec};
use super::Ident;
/// A collection of nodes which form a tree together with the nodes' children.
pub type SyntaxTree = SpanVec<SyntaxNode>;
/// A syntax node, which encompasses a single logical entity of parsed source
/// code.
#[derive(Debug, Clone, PartialEq)]
pub enum SyntaxNode {
/// Whitespace containing less than two newlines.
Spacing,
/// A forced line break.
Linebreak,
/// Italics were enabled / disabled.
ToggleItalic,
/// Bolder was enabled / disabled.
ToggleBolder,
/// Plain text.
Text(String),
/// Lines of raw text.
Raw(Vec<String>),
/// A paragraph of child nodes.
Par(SyntaxTree),
/// A function call.
Call(CallExpr),
}
/// An expression.
#[derive(Clone, PartialEq)]
pub enum Expr {
/// An identifier: `ident`.
Ident(Ident),
/// A string: `"string"`.
Str(String),
/// A boolean: `true, false`.
Bool(bool),
/// A number: `1.2, 200%`.
Number(f64),
/// A length: `2cm, 5.2in`.
Length(Length),
/// A color value with alpha channel: `#f79143ff`.
Color(RgbaColor),
/// A table expression: `(false, 12cm, greeting="hi")`.
Table(TableExpr),
/// A syntax tree containing typesetting content.
Tree(SyntaxTree),
/// A function call expression: `cmyk(37.7, 0, 3.9, 1.1)`.
Call(CallExpr),
/// An operation that negates the contained expression.
Neg(Box<Spanned<Expr>>),
/// An operation that adds the contained expressions.
Add(Box<Spanned<Expr>>, Box<Spanned<Expr>>),
/// An operation that subtracts the contained expressions.
Sub(Box<Spanned<Expr>>, Box<Spanned<Expr>>),
/// An operation that multiplies the contained expressions.
Mul(Box<Spanned<Expr>>, Box<Spanned<Expr>>),
/// An operation that divides the contained expressions.
Div(Box<Spanned<Expr>>, Box<Spanned<Expr>>),
}
impl Expr {
/// A natural-language name of the type of this expression, e.g.
/// "identifier".
pub fn name(&self) -> &'static str {
use Expr::*;
match self {
Ident(_) => "identifier",
Str(_) => "string",
Bool(_) => "bool",
Number(_) => "number",
Length(_) => "length",
Color(_) => "color",
Table(_) => "table",
Tree(_) => "syntax tree",
Call(_) => "function call",
Neg(_) => "negation",
Add(_, _) => "addition",
Sub(_, _) => "subtraction",
Mul(_, _) => "multiplication",
Div(_, _) => "division",
}
}
/// Evaluate the expression to a value.
pub async fn eval(
&self,
ctx: &LayoutContext<'_>,
f: &mut Feedback,
) -> Value {
use Expr::*;
match self {
Ident(i) => Value::Ident(i.clone()),
Str(s) => Value::Str(s.clone()),
&Bool(b) => Value::Bool(b),
&Number(n) => Value::Number(n),
&Length(s) => Value::Length(s),
&Color(c) => Value::Color(c),
Table(t) => Value::Table(t.eval(ctx, f).await),
Tree(t) => Value::Tree(t.clone()),
Call(call) => call.eval(ctx, f).await,
Neg(_) => todo!("eval neg"),
Add(_, _) => todo!("eval add"),
Sub(_, _) => todo!("eval sub"),
Mul(_, _) => todo!("eval mul"),
Div(_, _) => todo!("eval div"),
}
}
}
impl Debug for Expr {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
use Expr::*;
match self {
Ident(i) => i.fmt(f),
Str(s) => s.fmt(f),
Bool(b) => b.fmt(f),
Number(n) => n.fmt(f),
Length(s) => s.fmt(f),
Color(c) => c.fmt(f),
Table(t) => t.fmt(f),
Tree(t) => t.fmt(f),
Call(c) => c.fmt(f),
Neg(e) => write!(f, "-{:?}", e),
Add(a, b) => write!(f, "({:?} + {:?})", a, b),
Sub(a, b) => write!(f, "({:?} - {:?})", a, b),
Mul(a, b) => write!(f, "({:?} * {:?})", a, b),
Div(a, b) => write!(f, "({:?} / {:?})", a, b),
}
}
}
/// A table of expressions.
///
/// # Example
/// ```typst
/// (false, 12cm, greeting="hi")
/// ```
pub type TableExpr = Table<SpannedEntry<Expr>>;
impl TableExpr {
/// Evaluate the table expression to a table value.
pub fn eval<'a>(
&'a self,
ctx: &'a LayoutContext<'a>,
f: &'a mut Feedback,
) -> DynFuture<'a, TableValue> {
Box::pin(async move {
let mut table = TableValue::new();
for (key, entry) in self.iter() {
let val = entry.val.v.eval(ctx, f).await;
let spanned = Spanned::new(val, entry.val.span);
let entry = SpannedEntry::new(entry.key, spanned);
table.insert(key, entry);
}
table
})
}
}
/// An invocation of a function.
#[derive(Debug, Clone, PartialEq)]
pub struct CallExpr {
pub name: Spanned<Ident>,
pub args: TableExpr,
}
impl CallExpr {
/// Evaluate the call expression to a value.
pub async fn eval(&self, ctx: &LayoutContext<'_>, f: &mut Feedback) -> Value {
let name = self.name.v.as_str();
let span = self.name.span;
let args = self.args.eval(ctx, f).await;
if let Some(func) = ctx.scope.func(name) {
let pass = func(span, args, ctx.clone()).await;
f.extend(pass.feedback);
f.decorations.push(Spanned::new(Decoration::Resolved, span));
pass.output
} else {
error!(@f, span, "unknown function");
f.decorations.push(Spanned::new(Decoration::Unresolved, span));
Value::Table(args)
}
}
}
|
