Rename Value trait into TryFromExpr ✒

1 files changed, 0 insertions, 197 deletions

diff --git a/src/syntax/value.rs b/src/syntax/value.rs
deleted file mode 100644
index aa5049e0..00000000
--- a/src/syntax/value.rs
+++ /dev/null
@@ -1,197 +0,0 @@
-//! Value types for extracting function arguments.
-
-use fontdock::{FontStyle, FontWeight, FontWidth};
-
-use crate::layout::{Dir, SpecAlign};
-use crate::length::{Length, ScaleLength};
-use crate::paper::Paper;
-use crate::Feedback;
-use super::expr::*;
-use super::span::Spanned;
-use super::tree::SyntaxTree;
-
-/// Value types are used to extract values from functions, tuples and
-/// objects. They represent the value part of an argument.
-///
-/// # Example
-/// ```typst
-/// [func: 12pt, key="these are both values"]
-///        ^^^^      ^^^^^^^^^^^^^^^^^^^^^^^
-/// ```
-pub trait Value: Sized {
-    /// Try to parse this value from an expression.
-    ///
-    /// Returns `None` and generates an appropriate error if the expression is
-    /// not valid for this value type
-    fn parse(expr: Spanned<Expr>, f: &mut Feedback) -> Option<Self>;
-}
-
-impl<V: Value> Value for Spanned<V> {
-    fn parse(expr: Spanned<Expr>, f: &mut Feedback) -> Option<Self> {
-        let span = expr.span;
-        V::parse(expr, f).map(|v| Spanned { v, span })
-    }
-}
-
-macro_rules! match_value {
-    ($type:ty, $name:expr, $($p:pat => $r:expr),* $(,)?) => {
-        impl Value for $type {
-            fn parse(expr: Spanned<Expr>, f: &mut Feedback) -> Option<Self> {
-                #[allow(unreachable_patterns)]
-                match expr.v {
-                    $($p => Some($r)),*,
-                    other => {
-                        error!(
-                            @f, expr.span,
-                            "expected {}, found {}", $name, other.name()
-                        );
-                        None
-                    }
-                }
-            }
-        }
-    };
-}
-
-match_value!(Expr,   "expression", e => e);
-match_value!(Ident,  "identifier", Expr::Ident(i)  => i);
-match_value!(String, "string",     Expr::Str(s)    => s);
-match_value!(bool,   "bool",       Expr::Bool(b)   => b);
-match_value!(f64,    "number",     Expr::Number(n) => n);
-match_value!(Length, "length",     Expr::Length(l) => l);
-match_value!(SyntaxTree, "tree",   Expr::Tree(t)   => t);
-match_value!(Tuple,  "tuple",      Expr::Tuple(t)  => t);
-match_value!(Object, "object",     Expr::Object(o) => o);
-match_value!(ScaleLength, "number or length",
-    Expr::Length(length)    => ScaleLength::Absolute(length),
-    Expr::Number(scale) => ScaleLength::Scaled(scale),
-);
-
-/// A value type that matches identifiers and strings and implements
-/// `Into<String>`.
-pub struct StringLike(pub String);
-
-impl From<StringLike> for String {
-    fn from(like: StringLike) -> String {
-        like.0
-    }
-}
-
-match_value!(StringLike, "identifier or string",
-    Expr::Ident(Ident(s)) => StringLike(s),
-    Expr::Str(s) => StringLike(s),
-);
-
-macro_rules! ident_value {
-    ($type:ty, $name:expr, $parse:expr) => {
-        impl Value for $type {
-            fn parse(expr: Spanned<Expr>, f: &mut Feedback) -> Option<Self> {
-                if let Expr::Ident(ident) = expr.v {
-                    let val = $parse(ident.as_str());
-                    if val.is_none() {
-                        error!(@f, expr.span, "invalid {}", $name);
-                    }
-                    val
-                } else {
-                    error!(
-                        @f, expr.span,
-                        "expected {}, found {}", $name, expr.v.name()
-                    );
-                    None
-                }
-            }
-        }
-    };
-}
-
-ident_value!(Dir, "direction", |s| match s {
-    "ltr" => Some(Self::LTR),
-    "rtl" => Some(Self::RTL),
-    "ttb" => Some(Self::TTB),
-    "btt" => Some(Self::BTT),
-    _ => None,
-});
-
-ident_value!(SpecAlign, "alignment", |s| match s {
-    "left" => Some(Self::Left),
-    "right" => Some(Self::Right),
-    "top" => Some(Self::Top),
-    "bottom" => Some(Self::Bottom),
-    "center" => Some(Self::Center),
-    _ => None,
-});
-
-ident_value!(FontStyle, "font style", FontStyle::from_name);
-ident_value!(Paper, "paper", Paper::from_name);
-
-impl Value for FontWeight {
-    fn parse(expr: Spanned<Expr>, f: &mut Feedback) -> Option<Self> {
-        match expr.v {
-            Expr::Number(weight) => {
-                const MIN: u16 = 100;
-                const MAX: u16 = 900;
-
-                Some(Self(if weight < MIN as f64 {
-                    error!(@f, expr.span, "the minimum font weight is {}", MIN);
-                    MIN
-                } else if weight > MAX as f64 {
-                    error!(@f, expr.span, "the maximum font weight is {}", MAX);
-                    MAX
-                } else {
-                    weight.round() as u16
-                }))
-            }
-            Expr::Ident(ident) => {
-                let weight = Self::from_name(ident.as_str());
-                if weight.is_none() {
-                    error!(@f, expr.span, "invalid font weight");
-                }
-                weight
-            }
-            other => {
-                error!(
-                    @f, expr.span,
-                    "expected font weight (name or number), found {}",
-                    other.name(),
-                );
-                None
-            }
-        }
-    }
-}
-
-impl Value for FontWidth {
-    fn parse(expr: Spanned<Expr>, f: &mut Feedback) -> Option<Self> {
-        match expr.v {
-            Expr::Number(width) => {
-                const MIN: u16 = 1;
-                const MAX: u16 = 9;
-
-                Self::new(if width < MIN as f64 {
-                    error!(@f, expr.span, "the minimum font width is {}", MIN);
-                    MIN
-                } else if width > MAX as f64 {
-                    error!(@f, expr.span, "the maximum font width is {}", MAX);
-                    MAX
-                } else {
-                    width.round() as u16
-                })
-            }
-            Expr::Ident(ident) => {
-                let width = Self::from_name(ident.as_str());
-                if width.is_none() {
-                    error!(@f, expr.span, "invalid font width");
-                }
-                width
-            }
-            other => {
-                error!(
-                    @f, expr.span,
-                    "expected font width (name or number), found {}",
-                    other.name(),
-                );
-                None
-            }
-        }
-    }
-}