ok/jj
1
0
Fork 0
forked from mirrors/jj
jj/src/template_builder.rs

766 lines
31 KiB
Rust

// Copyright 2020-2023 The Jujutsu Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::collections::HashMap;
use itertools::Itertools as _;
use jujutsu_lib::backend::{Signature, Timestamp};
use crate::template_parser::{
self, ExpressionKind, ExpressionNode, FunctionCallNode, MethodCallNode, TemplateParseError,
TemplateParseResult,
};
use crate::templater::{
ConcatTemplate, ConditionalTemplate, IntoTemplate, LabelTemplate, ListPropertyTemplate,
ListTemplate, Literal, PlainTextFormattedProperty, PropertyPlaceholder, ReformatTemplate,
SeparateTemplate, Template, TemplateFunction, TemplateProperty, TimestampRange,
};
use crate::{text_util, time_util};
/// Callbacks to build language-specific evaluation objects from AST nodes.
pub trait TemplateLanguage<'a> {
type Context: 'a;
type Property: IntoTemplateProperty<'a, Self::Context>;
fn wrap_string(
&self,
property: impl TemplateProperty<Self::Context, Output = String> + 'a,
) -> Self::Property;
fn wrap_string_list(
&self,
property: impl TemplateProperty<Self::Context, Output = Vec<String>> + 'a,
) -> Self::Property;
fn wrap_boolean(
&self,
property: impl TemplateProperty<Self::Context, Output = bool> + 'a,
) -> Self::Property;
fn wrap_integer(
&self,
property: impl TemplateProperty<Self::Context, Output = i64> + 'a,
) -> Self::Property;
fn wrap_signature(
&self,
property: impl TemplateProperty<Self::Context, Output = Signature> + 'a,
) -> Self::Property;
fn wrap_timestamp(
&self,
property: impl TemplateProperty<Self::Context, Output = Timestamp> + 'a,
) -> Self::Property;
fn wrap_timestamp_range(
&self,
property: impl TemplateProperty<Self::Context, Output = TimestampRange> + 'a,
) -> Self::Property;
fn wrap_template(&self, template: Box<dyn Template<Self::Context> + 'a>) -> Self::Property;
fn wrap_list_template(
&self,
template: Box<dyn ListTemplate<Self::Context> + 'a>,
) -> Self::Property;
fn build_keyword(&self, name: &str, span: pest::Span) -> TemplateParseResult<Self::Property>;
fn build_method(
&self,
build_ctx: &BuildContext<Self::Property>,
property: Self::Property,
function: &FunctionCallNode,
) -> TemplateParseResult<Self::Property>;
}
/// Implements `TemplateLanguage::wrap_<type>()` functions.
///
/// - `impl_core_wrap_property_fns('a)` for `CoreTemplatePropertyKind`,
/// - `impl_core_wrap_property_fns('a, MyKind::Core)` for `MyKind::Core(..)`.
macro_rules! impl_core_wrap_property_fns {
($a:lifetime) => {
$crate::template_builder::impl_core_wrap_property_fns!($a, std::convert::identity);
};
($a:lifetime, $outer:path) => {
$crate::template_builder::impl_wrap_property_fns!(
$a, $crate::template_builder::CoreTemplatePropertyKind, $outer, {
wrap_string(String) => String,
wrap_string_list(Vec<String>) => StringList,
wrap_boolean(bool) => Boolean,
wrap_integer(i64) => Integer,
wrap_signature(jujutsu_lib::backend::Signature) => Signature,
wrap_timestamp(jujutsu_lib::backend::Timestamp) => Timestamp,
wrap_timestamp_range($crate::templater::TimestampRange) => TimestampRange,
}
);
fn wrap_template(
&self,
template: Box<dyn $crate::templater::Template<Self::Context> + $a>,
) -> Self::Property {
use $crate::template_builder::CoreTemplatePropertyKind as Kind;
$outer(Kind::Template(template))
}
fn wrap_list_template(
&self,
template: Box<dyn $crate::templater::ListTemplate<Self::Context> + $a>,
) -> Self::Property {
use $crate::template_builder::CoreTemplatePropertyKind as Kind;
$outer(Kind::ListTemplate(template))
}
};
}
macro_rules! impl_wrap_property_fns {
($a:lifetime, $kind:path, $outer:path, { $( $func:ident($ty:ty) => $var:ident, )+ }) => {
$(
fn $func(
&self,
property: impl $crate::templater::TemplateProperty<
Self::Context, Output = $ty> + $a,
) -> Self::Property {
use $kind as Kind; // https://github.com/rust-lang/rust/issues/48067
$outer(Kind::$var(Box::new(property)))
}
)+
};
}
pub(crate) use {impl_core_wrap_property_fns, impl_wrap_property_fns};
/// Provides access to basic template property types.
pub trait IntoTemplateProperty<'a, C> {
fn try_into_boolean(self) -> Option<Box<dyn TemplateProperty<C, Output = bool> + 'a>>;
fn try_into_integer(self) -> Option<Box<dyn TemplateProperty<C, Output = i64> + 'a>>;
fn try_into_plain_text(self) -> Option<Box<dyn TemplateProperty<C, Output = String> + 'a>>;
fn try_into_template(self) -> Option<Box<dyn Template<C> + 'a>>;
}
pub enum CoreTemplatePropertyKind<'a, I> {
String(Box<dyn TemplateProperty<I, Output = String> + 'a>),
StringList(Box<dyn TemplateProperty<I, Output = Vec<String>> + 'a>),
Boolean(Box<dyn TemplateProperty<I, Output = bool> + 'a>),
Integer(Box<dyn TemplateProperty<I, Output = i64> + 'a>),
Signature(Box<dyn TemplateProperty<I, Output = Signature> + 'a>),
Timestamp(Box<dyn TemplateProperty<I, Output = Timestamp> + 'a>),
TimestampRange(Box<dyn TemplateProperty<I, Output = TimestampRange> + 'a>),
// Similar to `TemplateProperty<I, Output = Box<dyn Template<()> + 'a>`, but doesn't
// capture `I` to produce `Template<()>`. The context `I` would have to be cloned
// to convert `Template<I>` to `Template<()>`.
Template(Box<dyn Template<I> + 'a>),
ListTemplate(Box<dyn ListTemplate<I> + 'a>),
}
impl<'a, I: 'a> IntoTemplateProperty<'a, I> for CoreTemplatePropertyKind<'a, I> {
fn try_into_boolean(self) -> Option<Box<dyn TemplateProperty<I, Output = bool> + 'a>> {
match self {
CoreTemplatePropertyKind::String(property) => {
Some(Box::new(TemplateFunction::new(property, |s| !s.is_empty())))
}
// TODO: should we allow implicit cast of List type?
CoreTemplatePropertyKind::Boolean(property) => Some(property),
_ => None,
}
}
fn try_into_integer(self) -> Option<Box<dyn TemplateProperty<I, Output = i64> + 'a>> {
match self {
CoreTemplatePropertyKind::Integer(property) => Some(property),
_ => None,
}
}
fn try_into_plain_text(self) -> Option<Box<dyn TemplateProperty<I, Output = String> + 'a>> {
match self {
CoreTemplatePropertyKind::String(property) => Some(property),
_ => {
let template = self.try_into_template()?;
Some(Box::new(PlainTextFormattedProperty::new(template)))
}
}
}
fn try_into_template(self) -> Option<Box<dyn Template<I> + 'a>> {
match self {
CoreTemplatePropertyKind::String(property) => Some(property.into_template()),
CoreTemplatePropertyKind::StringList(property) => Some(property.into_template()),
CoreTemplatePropertyKind::Boolean(property) => Some(property.into_template()),
CoreTemplatePropertyKind::Integer(property) => Some(property.into_template()),
CoreTemplatePropertyKind::Signature(property) => Some(property.into_template()),
CoreTemplatePropertyKind::Timestamp(property) => Some(property.into_template()),
CoreTemplatePropertyKind::TimestampRange(property) => Some(property.into_template()),
CoreTemplatePropertyKind::Template(template) => Some(template),
CoreTemplatePropertyKind::ListTemplate(template) => Some(template.into_template()),
}
}
}
/// Opaque struct that represents a template value.
pub struct Expression<P> {
property: P,
labels: Vec<String>,
}
impl<P> Expression<P> {
fn unlabeled(property: P) -> Self {
let labels = vec![];
Expression { property, labels }
}
fn with_label(property: P, label: impl Into<String>) -> Self {
let labels = vec![label.into()];
Expression { property, labels }
}
pub fn try_into_boolean<'a, C: 'a>(
self,
) -> Option<Box<dyn TemplateProperty<C, Output = bool> + 'a>>
where
P: IntoTemplateProperty<'a, C>,
{
self.property.try_into_boolean()
}
pub fn try_into_integer<'a, C: 'a>(
self,
) -> Option<Box<dyn TemplateProperty<C, Output = i64> + 'a>>
where
P: IntoTemplateProperty<'a, C>,
{
self.property.try_into_integer()
}
pub fn try_into_plain_text<'a, C: 'a>(
self,
) -> Option<Box<dyn TemplateProperty<C, Output = String> + 'a>>
where
P: IntoTemplateProperty<'a, C>,
{
self.property.try_into_plain_text()
}
pub fn try_into_template<'a, C: 'a>(self) -> Option<Box<dyn Template<C> + 'a>>
where
P: IntoTemplateProperty<'a, C>,
{
let template = self.property.try_into_template()?;
if self.labels.is_empty() {
Some(template)
} else {
Some(Box::new(LabelTemplate::new(template, Literal(self.labels))))
}
}
}
pub struct BuildContext<'i, P> {
/// Map of functions to create `L::Property`.
local_variables: HashMap<&'i str, &'i (dyn Fn() -> P)>,
}
fn build_method_call<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
method: &MethodCallNode,
) -> TemplateParseResult<Expression<L::Property>> {
let mut expression = build_expression(language, build_ctx, &method.object)?;
expression.property =
language.build_method(build_ctx, expression.property, &method.function)?;
expression.labels.push(method.function.name.to_owned());
Ok(expression)
}
pub fn build_core_method<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
property: CoreTemplatePropertyKind<'a, L::Context>,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
match property {
CoreTemplatePropertyKind::String(property) => {
build_string_method(language, build_ctx, property, function)
}
CoreTemplatePropertyKind::StringList(property) => {
build_formattable_list_method(language, build_ctx, property, function, |item| {
language.wrap_string(item)
})
}
CoreTemplatePropertyKind::Boolean(property) => {
build_boolean_method(language, build_ctx, property, function)
}
CoreTemplatePropertyKind::Integer(property) => {
build_integer_method(language, build_ctx, property, function)
}
CoreTemplatePropertyKind::Signature(property) => {
build_signature_method(language, build_ctx, property, function)
}
CoreTemplatePropertyKind::Timestamp(property) => {
build_timestamp_method(language, build_ctx, property, function)
}
CoreTemplatePropertyKind::TimestampRange(property) => {
build_timestamp_range_method(language, build_ctx, property, function)
}
CoreTemplatePropertyKind::Template(_) => {
Err(TemplateParseError::no_such_method("Template", function))
}
CoreTemplatePropertyKind::ListTemplate(template) => {
build_list_template_method(language, build_ctx, template, function)
}
}
}
fn build_string_method<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
self_property: impl TemplateProperty<L::Context, Output = String> + 'a,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
let property = match function.name {
"contains" => {
let [needle_node] = template_parser::expect_exact_arguments(function)?;
// TODO: or .try_into_string() to disable implicit type cast?
let needle_property = expect_plain_text_expression(language, build_ctx, needle_node)?;
language.wrap_boolean(TemplateFunction::new(
(self_property, needle_property),
|(haystack, needle)| haystack.contains(&needle),
))
}
"first_line" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |s| {
s.lines().next().unwrap_or_default().to_string()
}))
}
"lines" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string_list(TemplateFunction::new(self_property, |s| {
s.lines().map(|l| l.to_owned()).collect()
}))
}
"upper" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |s| s.to_uppercase()))
}
"lower" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |s| s.to_lowercase()))
}
_ => return Err(TemplateParseError::no_such_method("String", function)),
};
Ok(property)
}
fn build_boolean_method<'a, L: TemplateLanguage<'a>>(
_language: &L,
_build_ctx: &BuildContext<L::Property>,
_self_property: impl TemplateProperty<L::Context, Output = bool> + 'a,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
Err(TemplateParseError::no_such_method("Boolean", function))
}
fn build_integer_method<'a, L: TemplateLanguage<'a>>(
_language: &L,
_build_ctx: &BuildContext<L::Property>,
_self_property: impl TemplateProperty<L::Context, Output = i64> + 'a,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
Err(TemplateParseError::no_such_method("Integer", function))
}
fn build_signature_method<'a, L: TemplateLanguage<'a>>(
language: &L,
_build_ctx: &BuildContext<L::Property>,
self_property: impl TemplateProperty<L::Context, Output = Signature> + 'a,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
let property = match function.name {
"name" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |signature| {
signature.name
}))
}
"email" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |signature| {
signature.email
}))
}
"username" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |signature| {
let (username, _) = text_util::split_email(&signature.email);
username.to_owned()
}))
}
"timestamp" => {
template_parser::expect_no_arguments(function)?;
language.wrap_timestamp(TemplateFunction::new(self_property, |signature| {
signature.timestamp
}))
}
_ => return Err(TemplateParseError::no_such_method("Signature", function)),
};
Ok(property)
}
fn build_timestamp_method<'a, L: TemplateLanguage<'a>>(
language: &L,
_build_ctx: &BuildContext<L::Property>,
self_property: impl TemplateProperty<L::Context, Output = Timestamp> + 'a,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
let property = match function.name {
"ago" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |timestamp| {
time_util::format_timestamp_relative_to_now(&timestamp)
}))
}
"format" => {
// No dynamic string is allowed as the templater has no runtime error type.
let [format_node] = template_parser::expect_exact_arguments(function)?;
let format =
template_parser::expect_string_literal_with(format_node, |format, span| {
time_util::FormattingItems::parse(format).ok_or_else(|| {
TemplateParseError::unexpected_expression("Invalid time format", span)
})
})?
.into_owned();
language.wrap_string(TemplateFunction::new(self_property, move |timestamp| {
time_util::format_absolute_timestamp_with(&timestamp, &format)
}))
}
_ => return Err(TemplateParseError::no_such_method("Timestamp", function)),
};
Ok(property)
}
fn build_timestamp_range_method<'a, L: TemplateLanguage<'a>>(
language: &L,
_build_ctx: &BuildContext<L::Property>,
self_property: impl TemplateProperty<L::Context, Output = TimestampRange> + 'a,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
let property = match function.name {
"start" => {
template_parser::expect_no_arguments(function)?;
language.wrap_timestamp(TemplateFunction::new(self_property, |time_range| {
time_range.start
}))
}
"end" => {
template_parser::expect_no_arguments(function)?;
language.wrap_timestamp(TemplateFunction::new(self_property, |time_range| {
time_range.end
}))
}
"duration" => {
template_parser::expect_no_arguments(function)?;
language.wrap_string(TemplateFunction::new(self_property, |time_range| {
time_range.duration()
}))
}
_ => {
return Err(TemplateParseError::no_such_method(
"TimestampRange",
function,
))
}
};
Ok(property)
}
fn build_list_template_method<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
self_template: Box<dyn ListTemplate<L::Context> + 'a>,
function: &FunctionCallNode,
) -> TemplateParseResult<L::Property> {
let property = match function.name {
"join" => {
let [separator_node] = template_parser::expect_exact_arguments(function)?;
let separator = expect_template_expression(language, build_ctx, separator_node)?;
language.wrap_template(self_template.join(separator))
}
_ => return Err(TemplateParseError::no_such_method("ListTemplate", function)),
};
Ok(property)
}
/// Builds method call expression for printable list property.
pub fn build_formattable_list_method<'a, L, O>(
language: &L,
build_ctx: &BuildContext<L::Property>,
self_property: impl TemplateProperty<L::Context, Output = Vec<O>> + 'a,
function: &FunctionCallNode,
// TODO: Generic L: WrapProperty<L::Context, O> trait might be needed to support more
// list operations such as first()/slice(). For .map(), a simple callback works.
wrap_item: impl Fn(PropertyPlaceholder<O>) -> L::Property,
) -> TemplateParseResult<L::Property>
where
L: TemplateLanguage<'a>,
O: Template<()> + Clone + 'a,
{
let property = match function.name {
"join" => {
let [separator_node] = template_parser::expect_exact_arguments(function)?;
let separator = expect_template_expression(language, build_ctx, separator_node)?;
let template =
ListPropertyTemplate::new(self_property, separator, |_, formatter, item| {
item.format(&(), formatter)
});
language.wrap_template(Box::new(template))
}
"map" => build_map_operation(language, build_ctx, self_property, function, wrap_item)?,
_ => return Err(TemplateParseError::no_such_method("List", function)),
};
Ok(property)
}
pub fn build_unformattable_list_method<'a, L, O>(
language: &L,
build_ctx: &BuildContext<L::Property>,
self_property: impl TemplateProperty<L::Context, Output = Vec<O>> + 'a,
function: &FunctionCallNode,
wrap_item: impl Fn(PropertyPlaceholder<O>) -> L::Property,
) -> TemplateParseResult<L::Property>
where
L: TemplateLanguage<'a>,
O: Clone + 'a,
{
let property = match function.name {
// No "join"
"map" => build_map_operation(language, build_ctx, self_property, function, wrap_item)?,
_ => return Err(TemplateParseError::no_such_method("List", function)),
};
Ok(property)
}
/// Builds expression that extracts iterable property and applies template to
/// each item.
///
/// `wrap_item()` is the function to wrap a list item of type `O` as a property.
fn build_map_operation<'a, L, O, P>(
language: &L,
build_ctx: &BuildContext<L::Property>,
self_property: P,
function: &FunctionCallNode,
wrap_item: impl Fn(PropertyPlaceholder<O>) -> L::Property,
) -> TemplateParseResult<L::Property>
where
L: TemplateLanguage<'a>,
P: TemplateProperty<L::Context> + 'a,
P::Output: IntoIterator<Item = O>,
O: Clone + 'a,
{
// Build an item template with placeholder property, then evaluate it
// for each item.
//
// It would be nice if we could build a template of (L::Context, O)
// input, but doing that for a generic item type wouldn't be easy. It's
// also invalid to convert &C to &(C, _).
let [lambda_node] = template_parser::expect_exact_arguments(function)?;
let item_placeholder = PropertyPlaceholder::new();
let item_template = template_parser::expect_lambda_with(lambda_node, |lambda, _span| {
let item_fn = || wrap_item(item_placeholder.clone());
let mut local_variables = build_ctx.local_variables.clone();
if let [name] = lambda.params.as_slice() {
local_variables.insert(name, &item_fn);
} else {
return Err(TemplateParseError::unexpected_expression(
"Expected 1 lambda parameters",
lambda.params_span,
));
}
let build_ctx = BuildContext { local_variables };
expect_template_expression(language, &build_ctx, &lambda.body)
})?;
let list_template = ListPropertyTemplate::new(
self_property,
Literal(" "), // separator
move |context, formatter, item| {
item_placeholder.with_value(item, || item_template.format(context, formatter))
},
);
Ok(language.wrap_list_template(Box::new(list_template)))
}
fn build_global_function<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
function: &FunctionCallNode,
) -> TemplateParseResult<Expression<L::Property>> {
let property = match function.name {
"fill" => {
let [width_node, content_node] = template_parser::expect_exact_arguments(function)?;
let width = expect_integer_expression(language, build_ctx, width_node)?;
let content = expect_template_expression(language, build_ctx, content_node)?;
let template = ReformatTemplate::new(content, move |context, formatter, recorded| {
let width = width.extract(context).try_into().unwrap_or(0);
text_util::write_wrapped(formatter, recorded, width)
});
language.wrap_template(Box::new(template))
}
"indent" => {
let [prefix_node, content_node] = template_parser::expect_exact_arguments(function)?;
let prefix = expect_template_expression(language, build_ctx, prefix_node)?;
let content = expect_template_expression(language, build_ctx, content_node)?;
let template = ReformatTemplate::new(content, move |context, formatter, recorded| {
text_util::write_indented(formatter, recorded, |formatter| {
// If Template::format() returned a custom error type, we would need to
// handle template evaluation error out of this closure:
// prefix.format(context, &mut prefix_recorder)?;
// write_indented(formatter, recorded, |formatter| {
// prefix_recorder.replay(formatter)
// })
prefix.format(context, formatter)
})
});
language.wrap_template(Box::new(template))
}
"label" => {
let [label_node, content_node] = template_parser::expect_exact_arguments(function)?;
let label_property = expect_plain_text_expression(language, build_ctx, label_node)?;
let content = expect_template_expression(language, build_ctx, content_node)?;
let labels = TemplateFunction::new(label_property, |s| {
s.split_whitespace().map(ToString::to_string).collect()
});
language.wrap_template(Box::new(LabelTemplate::new(content, labels)))
}
"if" => {
let ([condition_node, true_node], [false_node]) =
template_parser::expect_arguments(function)?;
let condition = expect_boolean_expression(language, build_ctx, condition_node)?;
let true_template = expect_template_expression(language, build_ctx, true_node)?;
let false_template = false_node
.map(|node| expect_template_expression(language, build_ctx, node))
.transpose()?;
let template = ConditionalTemplate::new(condition, true_template, false_template);
language.wrap_template(Box::new(template))
}
"concat" => {
let contents = function
.args
.iter()
.map(|node| expect_template_expression(language, build_ctx, node))
.try_collect()?;
language.wrap_template(Box::new(ConcatTemplate(contents)))
}
"separate" => {
let ([separator_node], content_nodes) =
template_parser::expect_some_arguments(function)?;
let separator = expect_template_expression(language, build_ctx, separator_node)?;
let contents = content_nodes
.iter()
.map(|node| expect_template_expression(language, build_ctx, node))
.try_collect()?;
language.wrap_template(Box::new(SeparateTemplate::new(separator, contents)))
}
_ => return Err(TemplateParseError::no_such_function(function)),
};
Ok(Expression::unlabeled(property))
}
/// Builds intermediate expression tree from AST nodes.
pub fn build_expression<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
node: &ExpressionNode,
) -> TemplateParseResult<Expression<L::Property>> {
match &node.kind {
ExpressionKind::Identifier(name) => {
if let Some(make) = build_ctx.local_variables.get(name) {
// Don't label a local variable with its name
Ok(Expression::unlabeled(make()))
} else {
let property = language.build_keyword(name, node.span)?;
Ok(Expression::with_label(property, *name))
}
}
ExpressionKind::Integer(value) => {
let property = language.wrap_integer(Literal(*value));
Ok(Expression::unlabeled(property))
}
ExpressionKind::String(value) => {
let property = language.wrap_string(Literal(value.clone()));
Ok(Expression::unlabeled(property))
}
ExpressionKind::Concat(nodes) => {
let templates = nodes
.iter()
.map(|node| expect_template_expression(language, build_ctx, node))
.try_collect()?;
let property = language.wrap_template(Box::new(ConcatTemplate(templates)));
Ok(Expression::unlabeled(property))
}
ExpressionKind::FunctionCall(function) => {
build_global_function(language, build_ctx, function)
}
ExpressionKind::MethodCall(method) => build_method_call(language, build_ctx, method),
ExpressionKind::Lambda(_) => Err(TemplateParseError::unexpected_expression(
"Lambda cannot be defined here",
node.span,
)),
ExpressionKind::AliasExpanded(id, subst) => build_expression(language, build_ctx, subst)
.map_err(|e| e.within_alias_expansion(*id, node.span)),
}
}
/// Builds template evaluation tree from AST nodes, with fresh build context.
pub fn build<'a, L: TemplateLanguage<'a>>(
language: &L,
node: &ExpressionNode,
) -> TemplateParseResult<Box<dyn Template<L::Context> + 'a>> {
let build_ctx = BuildContext {
local_variables: HashMap::new(),
};
expect_template_expression(language, &build_ctx, node)
}
pub fn expect_boolean_expression<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
node: &ExpressionNode,
) -> TemplateParseResult<Box<dyn TemplateProperty<L::Context, Output = bool> + 'a>> {
build_expression(language, build_ctx, node)?
.try_into_boolean()
.ok_or_else(|| TemplateParseError::expected_type("Boolean", node.span))
}
pub fn expect_integer_expression<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
node: &ExpressionNode,
) -> TemplateParseResult<Box<dyn TemplateProperty<L::Context, Output = i64> + 'a>> {
build_expression(language, build_ctx, node)?
.try_into_integer()
.ok_or_else(|| TemplateParseError::expected_type("Integer", node.span))
}
pub fn expect_plain_text_expression<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
node: &ExpressionNode,
) -> TemplateParseResult<Box<dyn TemplateProperty<L::Context, Output = String> + 'a>> {
// Since any formattable type can be converted to a string property,
// the expected type is not a String, but a Template.
build_expression(language, build_ctx, node)?
.try_into_plain_text()
.ok_or_else(|| TemplateParseError::expected_type("Template", node.span))
}
pub fn expect_template_expression<'a, L: TemplateLanguage<'a>>(
language: &L,
build_ctx: &BuildContext<L::Property>,
node: &ExpressionNode,
) -> TemplateParseResult<Box<dyn Template<L::Context> + 'a>> {
build_expression(language, build_ctx, node)?
.try_into_template()
.ok_or_else(|| TemplateParseError::expected_type("Template", node.span))
}