Rename ast to parser

Signed-off-by: Marcel Müller <neikos@neikos.email>

benches/asting.rs

@@ -19,8 +19,8 @@ fn asting_benchmark(c: &mut Criterion) {
         parsing.throughput(criterion::Throughput::Bytes(input.len() as u64));
         parsing.bench_with_input(BenchmarkId::from_parameter(size), &input, |b, input| {
             b.iter(|| {
-                let tokens = nomo::parser::parse(input.clone()).unwrap();
-                let _ast = nomo::ast::parse(tokens.tokens()).unwrap();
+                let tokens = nomo::lexer::parse(input.clone()).unwrap();
+                let _ast = nomo::parser::parse(tokens.tokens()).unwrap();
             });
         });
     }
@@ -43,8 +43,8 @@ fn asting_nested(c: &mut Criterion) {
         parsing.throughput(criterion::Throughput::Bytes(input.len() as u64));
         parsing.bench_with_input(BenchmarkId::from_parameter(size), &input, |b, input| {
             b.iter(|| {
-                let tokens = nomo::parser::parse(input.clone()).unwrap();
-                let _ast = nomo::ast::parse(tokens.tokens()).unwrap();
+                let tokens = nomo::lexer::parse(input.clone()).unwrap();
+                let _ast = nomo::parser::parse(tokens.tokens()).unwrap();
             });
         });
     }

benches/parsing.rs

@@ -18,7 +18,7 @@ fn parsing_benchmark(c: &mut Criterion) {
 
         parsing.throughput(criterion::Throughput::Bytes(input.len() as u64));
         parsing.bench_with_input(BenchmarkId::from_parameter(size), &input, |b, input| {
-            b.iter(|| nomo::parser::parse(input.clone()).unwrap());
+            b.iter(|| nomo::lexer::parse(input.clone()).unwrap());
         });
     }
 }
@@ -39,7 +39,7 @@ fn parsing_nested(c: &mut Criterion) {
 
         parsing.throughput(criterion::Throughput::Bytes(input.len() as u64));
         parsing.bench_with_input(BenchmarkId::from_parameter(size), &input, |b, input| {
-            b.iter(|| nomo::parser::parse(input.clone()).unwrap());
+            b.iter(|| nomo::lexer::parse(input.clone()).unwrap());
         });
     }
 }

fuzz/fuzz_targets/fuzz_target_1.rs

@@ -4,11 +4,11 @@ use libfuzzer_sys::Corpus;
 use libfuzzer_sys::fuzz_target;
 
 fuzz_target!(|data: String| -> Corpus {
-    let Ok(parsed) = nomo::parser::parse(data.into()) else {
+    let Ok(parsed) = nomo::lexer::parse(data.into()) else {
         return Corpus::Reject;
     };
 
-    let Ok(ast) = nomo::ast::parse(parsed.tokens()) else {
+    let Ok(ast) = nomo::parser::parse(parsed.tokens()) else {
         return Corpus::Keep;
     };
 

src/emit/mod.rs

@@ -1,9 +1,9 @@
 use std::collections::BTreeMap;
 
-use crate::ast::TemplateAstExpr;
+use crate::parser::TemplateAstExpr;
 use crate::input::NomoInput;
-use crate::parser::TemplateToken;
-use crate::parser::TokenOperator;
+use crate::lexer::TemplateToken;
+use crate::lexer::TokenOperator;
 use crate::value::NomoValue;
 
 pub struct EmitMachine {
@@ -102,6 +102,11 @@ pub enum Instruction {
         right_slot: VariableSlot,
         result_slot: VariableSlot,
     },
+    FunctionCall {
+        name: NomoInput,
+        args: Vec<VariableSlot>,
+        slot: VariableSlot,
+    },
 }
 
 #[derive(Debug, Clone)]
@@ -110,7 +115,7 @@ pub struct VMInstructions {
     pub instructions: Vec<Instruction>,
 }
 
-pub fn emit_machine(input: crate::ast::TemplateAst<'_>) -> VMInstructions {
+pub fn emit_machine(input: crate::parser::TemplateAst<'_>) -> VMInstructions {
     let mut eval = vec![];
 
     let mut machine = EmitMachine {
@@ -166,7 +171,7 @@ fn emit_ast_expr(
             let end_label = machine.reserve_label();
             let mut end_indices = vec![];
 
-            let mut previous_post_whitespace_content: &Option<crate::parser::TemplateToken> = &None;
+            let mut previous_post_whitespace_content: &Option<TemplateToken> = &None;
             let mut previous_jump: Option<LabelSlot> = None;
 
             loop {
@@ -417,6 +422,7 @@ fn emit_ast_expr(
         | TemplateAstExpr::ForElse
         | TemplateAstExpr::Invalid { .. }
         | TemplateAstExpr::Literal { .. }
+        | TemplateAstExpr::FunctionCall { .. }
         | TemplateAstExpr::Operation { .. }
         | TemplateAstExpr::VariableAccess { .. } => eval.push(Instruction::Abort),
     }
@@ -455,6 +461,20 @@ fn emit_expr_load(
                 result_slot: emit_slot,
             });
         }
+        TemplateAstExpr::FunctionCall { name, args } => {
+            let mut arg_slots = vec![];
+            for arg in args {
+                let slot = machine.reserve_slot();
+                emit_expr_load(machine, eval, slot, arg);
+                arg_slots.push(slot);
+            }
+
+            eval.push(Instruction::FunctionCall {
+                name: name.source(),
+                args: arg_slots,
+                slot: emit_slot,
+            });
+        }
         TemplateAstExpr::Invalid { .. } => eval.push(Instruction::Abort),
         TemplateAstExpr::StaticContent { .. } | TemplateAstExpr::Interpolation { .. } => {
             unreachable!("Invalid AST here")
@@ -480,9 +500,9 @@ mod tests {
     fn check_simple_variable_interpolation() {
         let input = "Hello {{= world }}";
 
-        let parsed = crate::parser::parse(input.into()).unwrap();
+        let parsed = crate::lexer::parse(input.into()).unwrap();
 
-        let ast = crate::ast::parse(parsed.tokens()).unwrap();
+        let ast = crate::parser::parse(parsed.tokens()).unwrap();
 
         let emit = emit_machine(ast);
 
@@ -516,9 +536,22 @@ mod tests {
     fn check_if_else_if() {
         let input = "{{ if foo }} foo {{ else if bar }} bar {{ else }} foobar {{ end }}";
 
-        let parsed = crate::parser::parse(input.into()).unwrap();
+        let parsed = crate::lexer::parse(input.into()).unwrap();
 
-        let ast = crate::ast::parse(parsed.tokens()).unwrap();
+        let ast = crate::parser::parse(parsed.tokens()).unwrap();
+
+        let emit = emit_machine(ast);
+
+        insta::assert_debug_snapshot!(emit);
+    }
+
+    #[test]
+    fn check_function_call() {
+        let input = "{{ if foo(23) }} bar {{ else }} foobar {{ end }}";
+
+        let parsed = crate::lexer::parse(input.into()).unwrap();
+
+        let ast = crate::parser::parse(parsed.tokens()).unwrap();
 
         let emit = emit_machine(ast);
 

src/emit/snapshots/nomo__emit__tests__check_function_call.snap

@@ -0,0 +1,79 @@
+---
+source: src/emit/mod.rs
+expression: emit
+---
+VMInstructions {
+    labels: {
+        LabelSlot {
+            index: 0,
+        }: 13,
+        LabelSlot {
+            index: 3,
+        }: 8,
+    },
+    instructions: [
+        LoadLiteralToSlot {
+            source: [Literal(Integer(23))]"23" (10..12),
+            value: Integer {
+                value: 23,
+            },
+            slot: VariableSlot {
+                index: 2,
+            },
+        },
+        FunctionCall {
+            name: "foo" (6..9),
+            args: [
+                VariableSlot {
+                    index: 2,
+                },
+            ],
+            slot: VariableSlot {
+                index: 1,
+            },
+        },
+        JumpIfNotTrue {
+            emit_slot: VariableSlot {
+                index: 1,
+            },
+            jump: LabelSlot {
+                index: 3,
+            },
+        },
+        AppendContent {
+            content: " " (16..17),
+        },
+        AppendContent {
+            content: "bar" (17..20),
+        },
+        AppendContent {
+            content: " " (20..21),
+        },
+        Jump {
+            jump: LabelSlot {
+                index: 0,
+            },
+        },
+        AppendContent {
+            content: " " (16..17),
+        },
+        AppendContent {
+            content: " " (31..32),
+        },
+        AppendContent {
+            content: "foobar" (32..38),
+        },
+        AppendContent {
+            content: " " (38..39),
+        },
+        Jump {
+            jump: LabelSlot {
+                index: 0,
+            },
+        },
+        AppendContent {
+            content: " " (31..32),
+        },
+        NoOp,
+    ],
+}

src/eval/mod.rs

@@ -7,6 +7,7 @@ use crate::Context;
 use crate::emit::Instruction;
 use crate::emit::VMInstructions;
 use crate::emit::VariableSlot;
+use crate::functions::FunctionMap;
 use crate::input::NomoInput;
 use crate::value::NomoValue;
 
@@ -69,7 +70,11 @@ impl Scope {
     clippy::unnecessary_to_owned,
     reason = "We cannot do the suggested way as the lifetimes would not match up"
 )]
-pub fn execute(vm: &VMInstructions, global_context: &Context) -> Result<String, EvaluationError> {
+pub fn execute(
+    available_functions: &FunctionMap,
+    vm: &VMInstructions,
+    global_context: &Context,
+) -> Result<String, EvaluationError> {
     let mut output = String::new();
 
     let mut scopes = Scope {
@@ -197,17 +202,28 @@ pub fn execute(vm: &VMInstructions, global_context: &Context) -> Result<String,
                 let right_value = scopes.get(right_slot);
 
                 let result = match op {
-                    crate::parser::TokenOperator::Plus => left_value.try_add(right_value),
-                    crate::parser::TokenOperator::Minus => left_value.try_sub(right_value),
-                    crate::parser::TokenOperator::Times => left_value.try_mul(right_value),
-                    crate::parser::TokenOperator::Divide => left_value.try_div(right_value),
-                    crate::parser::TokenOperator::And => left_value.try_and(right_value),
-                    crate::parser::TokenOperator::Or => left_value.try_or(right_value),
+                    crate::lexer::TokenOperator::Plus => left_value.try_add(right_value),
+                    crate::lexer::TokenOperator::Minus => left_value.try_sub(right_value),
+                    crate::lexer::TokenOperator::Times => left_value.try_mul(right_value),
+                    crate::lexer::TokenOperator::Divide => left_value.try_div(right_value),
+                    crate::lexer::TokenOperator::And => left_value.try_and(right_value),
+                    crate::lexer::TokenOperator::Or => left_value.try_or(right_value),
                     _ => todo!(),
                 };
 
                 scopes.insert_into_slot(*result_slot, result.unwrap());
             }
+            Instruction::FunctionCall { name, args, slot } => {
+                let args = args.iter().map(|slot| scopes.get(slot)).cloned().collect();
+
+                let value = available_functions
+                    .get(name.as_str())
+                    .unwrap()
+                    .call(args)
+                    .unwrap();
+
+                scopes.insert_into_slot(*slot, value);
+            }
         }
 
         ip += 1;
@@ -220,20 +236,22 @@ pub fn execute(vm: &VMInstructions, global_context: &Context) -> Result<String,
 mod tests {
     use crate::Context;
     use crate::eval::execute;
+    use crate::functions::FunctionMap;
+    use crate::functions::NomoFunctionError;
 
     #[test]
     fn check_simple_variable_interpolation() {
         let input = "Hello {{= world }}";
 
-        let parsed = crate::parser::parse(input.into()).unwrap();
+        let parsed = crate::lexer::parse(input.into()).unwrap();
 
-        let ast = crate::ast::parse(parsed.tokens()).unwrap();
+        let ast = crate::parser::parse(parsed.tokens()).unwrap();
 
         let emit = crate::emit::emit_machine(ast);
 
         let mut context = Context::new();
         context.insert("world", "World");
-        let output = execute(&emit, &context);
+        let output = execute(&FunctionMap::default(), &emit, &context);
 
         insta::assert_debug_snapshot!(output, @r#"
         Ok(
@@ -241,4 +259,31 @@ mod tests {
         )
         "#);
     }
+
+    #[test]
+    fn check_method_call() {
+        let input = "Hello {{= foo(world) }}";
+
+        let parsed = crate::lexer::parse(input.into()).unwrap();
+
+        let ast = crate::parser::parse(parsed.tokens()).unwrap();
+
+        let emit = crate::emit::emit_machine(ast);
+
+        let mut context = Context::new();
+        context.insert("world", "World");
+        let mut function_map = FunctionMap::default();
+
+        function_map.register("foo", |arg: String| -> Result<String, NomoFunctionError> {
+            Ok(arg.to_uppercase())
+        });
+
+        let output = execute(&function_map, &emit, &context);
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            "Hello WORLD",
+        )
+        "#);
+    }
 }

src/functions.rs

@@ -0,0 +1,175 @@
+use std::any::Any;
+use std::collections::HashMap;
+
+use displaydoc::Display;
+use thiserror::Error;
+
+use crate::NomoValueError;
+use crate::value::NomoValue;
+
+#[derive(Debug, Error, Display)]
+pub enum NomoFunctionError {
+    /// Received {received} arguments, but this function only takes {expected}
+    WrongArgumentCount { received: usize, expected: usize },
+
+    /// The argument at this position is of the wrong type
+    InvalidArgumentType { index: usize },
+
+    /// A user-provided error
+    #[error(transparent)]
+    CustomError {
+        custom: Box<dyn std::error::Error + Send + Sync>,
+    },
+}
+
+pub trait NomoFunction<T>: 'static + Send + Sync {
+    fn call(&self, args: Vec<NomoValue>) -> Result<NomoValue, NomoFunctionError>;
+}
+
+#[derive(Default)]
+pub struct FunctionMap {
+    funcs: HashMap<String, ErasedNomoFunction>,
+}
+
+impl FunctionMap {
+    pub fn register<NF: NomoFunction<T>, T>(&mut self, name: impl Into<String>, func: NF) {
+        self.funcs
+            .insert(name.into(), ErasedNomoFunction::erase(func));
+    }
+
+    pub fn get(&self, name: impl AsRef<str>) -> Option<&ErasedNomoFunction> {
+        self.funcs.get(name.as_ref())
+    }
+}
+
+pub struct ErasedNomoFunction {
+    func: Box<dyn Any + Send + Sync>,
+    call_fn: fn(&dyn Any, Vec<NomoValue>) -> Result<NomoValue, NomoFunctionError>,
+}
+
+impl ErasedNomoFunction {
+    pub fn call(&self, args: Vec<NomoValue>) -> Result<NomoValue, NomoFunctionError> {
+        (self.call_fn)(&*self.func, args)
+    }
+
+    pub fn erase<NF, T>(f: NF) -> ErasedNomoFunction
+    where
+        NF: NomoFunction<T>,
+    {
+        ErasedNomoFunction {
+            func: Box::new(f),
+            call_fn: |nf, args| {
+                let nf: &NF = nf.downcast_ref().unwrap();
+
+                nf.call(args)
+            },
+        }
+    }
+}
+
+#[rustfmt::skip]
+macro_rules! for_all_tuples {
+    ($name:ident) => {
+        $name!([], T1);
+        $name!([T1], T2);
+        $name!([T1, T2], T3);
+        $name!([T1, T2, T3], T4);
+        $name!([T1, T2, T3, T4], T5);
+        $name!([T1, T2, T3, T4, T5], T6);
+        $name!([T1, T2, T3, T4, T5, T6], T7);
+        $name!([T1, T2, T3, T4, T5, T6, T7], T8);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8], T9);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8, T9], T10);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8, T9, T10], T11);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11], T12);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12], T13);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13], T14);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14], T15);
+        $name!([T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15], T16);
+    };
+}
+
+macro_rules! impl_nomo_function {
+    ([$($ty:ident),*], $last:ident) => {
+        impl<F, Res, Error, $($ty,)* $last> NomoFunction<($($ty,)* $last,)> for F
+        where
+            F: Fn($($ty,)* $last,) -> Result<Res, Error>,
+            F: Send + Sync + 'static,
+            Res: Into<NomoValue>,
+            Error: Into<NomoFunctionError>,
+            $( $ty: TryFrom<NomoValue, Error = NomoValueError>, )*
+            $last: TryFrom<NomoValue, Error = NomoValueError>,
+        {
+            fn call(&self, args: Vec<NomoValue>) -> Result<NomoValue, NomoFunctionError> {
+                let arg_count = args.len();
+
+                let total_count = 1 $(+ impl_nomo_function!(count $ty))*;
+
+                if arg_count != total_count {
+                    return Err(NomoFunctionError::WrongArgumentCount {
+                        expected: total_count,
+                        received: arg_count,
+                    });
+                }
+
+                let mut args = args.into_iter();
+
+                #[allow(unused_mut)]
+                let mut idx = 0;
+
+                let val = (self)(
+                        $({
+                            let val = $ty::try_from(args.next().unwrap()).map_err(|_| NomoFunctionError::InvalidArgumentType { index: idx })?;
+                            idx += 1;
+                            val
+                        },)*
+                        $last::try_from(args.next().unwrap()).map_err(|_| NomoFunctionError::InvalidArgumentType { index: idx })?,
+                    );
+
+                val.map(Into::into).map_err(Into::into)
+            }
+        }
+    };
+
+    (count $ty:ident) => {
+        1
+    }
+}
+
+for_all_tuples!(impl_nomo_function);
+
+impl<F, Res, Error> NomoFunction<()> for F
+where
+    F: Fn() -> Result<Res, Error> + Send + Sync + 'static,
+    Res: Into<NomoValue>,
+    Error: Into<NomoFunctionError>,
+{
+    fn call(&self, args: Vec<NomoValue>) -> Result<NomoValue, NomoFunctionError> {
+        let arg_count = args.len();
+
+        if arg_count != 0 {
+            return Err(NomoFunctionError::WrongArgumentCount {
+                received: arg_count,
+                expected: 0,
+            });
+        }
+
+        let val = (self)();
+
+        val.map(Into::into).map_err(Into::into)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::functions::ErasedNomoFunction;
+    use crate::functions::NomoFunctionError;
+
+    #[expect(dead_code, reason = "This is a compile test")]
+    fn check_various_methods() {
+        ErasedNomoFunction::erase(|name: String| -> Result<String, NomoFunctionError> { Ok(name) });
+        ErasedNomoFunction::erase(|left: u64, right: u64| -> Result<u64, NomoFunctionError> {
+            Ok(left + right)
+        });
+    }
+}

src/lexer/mod.rs

@@ -0,0 +1,908 @@
+use std::sync::Arc;
+
+use annotate_snippets::AnnotationKind;
+use annotate_snippets::Level;
+use annotate_snippets::Renderer;
+use annotate_snippets::Snippet;
+use thiserror::Error;
+use winnow::LocatingSlice;
+use winnow::Parser;
+use winnow::RecoverableParser;
+use winnow::ascii::alpha1;
+use winnow::ascii::digit1;
+use winnow::ascii::multispace0;
+use winnow::ascii::multispace1;
+use winnow::combinator::alt;
+use winnow::combinator::cut_err;
+use winnow::combinator::dispatch;
+use winnow::combinator::empty;
+use winnow::combinator::eof;
+use winnow::combinator::fail;
+use winnow::combinator::not;
+use winnow::combinator::opt;
+use winnow::combinator::peek;
+use winnow::combinator::preceded;
+use winnow::combinator::repeat_till;
+use winnow::combinator::terminated;
+use winnow::combinator::trace;
+use winnow::error::AddContext;
+use winnow::error::FromRecoverableError;
+use winnow::error::ModalError;
+use winnow::error::ParserError;
+use winnow::stream::Location;
+use winnow::stream::Recoverable;
+use winnow::stream::Stream;
+use winnow::token::any;
+use winnow::token::one_of;
+use winnow::token::rest;
+use winnow::token::take_until;
+use winnow::token::take_while;
+
+use crate::SourceSpan;
+use crate::input::NomoInput;
+use crate::resume_after_cut;
+
+type Input<'input> = Recoverable<LocatingSlice<NomoInput>, ParseError>;
+type PResult<'input, T> = Result<T, ParseError>;
+
+#[derive(Debug, Error)]
+pub struct ParseFailure {
+    input: Arc<str>,
+    errors: Vec<ParseError>,
+}
+
+impl std::fmt::Display for ParseFailure {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(&self.to_report())
+    }
+}
+
+impl ParseFailure {
+    fn from_errors(errors: Vec<ParseError>, input: NomoInput) -> ParseFailure {
+        ParseFailure {
+            input: Arc::from(input.to_string()),
+            errors,
+        }
+    }
+
+    pub fn to_report(&self) -> String {
+        let reports = self
+            .errors
+            .iter()
+            .map(|error| {
+                Level::ERROR
+                    .primary_title(
+                        error
+                            .message
+                            .as_deref()
+                            .unwrap_or("An error occurred while parsing"),
+                    )
+                    .element(
+                        Snippet::source(self.input.as_ref()).annotation(
+                            AnnotationKind::Primary
+                                .span(error.span.clone().map(|s| s.range).unwrap_or_else(|| 0..0)),
+                        ),
+                    )
+                    .elements(error.help.as_ref().map(|help| Level::HELP.message(help)))
+            })
+            .collect::<Vec<_>>();
+
+        let renderer =
+            Renderer::styled().decor_style(annotate_snippets::renderer::DecorStyle::Unicode);
+        renderer.render(&reports)
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ParseError {
+    pub(crate) message: Option<String>,
+    pub(crate) help: Option<String>,
+    pub(crate) span: Option<crate::SourceSpan>,
+
+    is_fatal: bool,
+}
+
+impl ParseError {
+    fn ctx() -> Self {
+        ParseError {
+            message: None,
+            help: None,
+            span: None,
+
+            is_fatal: false,
+        }
+    }
+
+    fn msg(mut self, message: &str) -> Self {
+        self.message = Some(message.to_string());
+        self
+    }
+
+    fn help(mut self, help: &str) -> Self {
+        self.help = Some(help.to_string());
+        self
+    }
+}
+
+impl ModalError for ParseError {
+    fn cut(mut self) -> Self {
+        self.is_fatal = true;
+        self
+    }
+
+    fn backtrack(mut self) -> Self {
+        self.is_fatal = false;
+        self
+    }
+}
+
+impl<'input> FromRecoverableError<Input<'input>, ParseError> for ParseError {
+    fn from_recoverable_error(
+        token_start: &<Input<'input> as winnow::stream::Stream>::Checkpoint,
+        _err_start: &<Input<'input> as winnow::stream::Stream>::Checkpoint,
+        input: &Input<'input>,
+        mut e: ParseError,
+    ) -> Self {
+        e.span = e
+            .span
+            .or_else(|| Some(span_from_checkpoint(input, token_start)));
+
+        e
+    }
+}
+
+impl<'input> AddContext<Input<'input>, ParseError> for ParseError {
+    fn add_context(
+        mut self,
+        _input: &Input<'input>,
+        _token_start: &<Input<'input> as Stream>::Checkpoint,
+        context: ParseError,
+    ) -> Self {
+        self.message = context.message.or(self.message);
+        self.help = context.help.or(self.help);
+        self
+    }
+}
+
+fn span_from_checkpoint<I: Stream + Location>(
+    input: &I,
+    token_start: &<I as Stream>::Checkpoint,
+) -> SourceSpan {
+    let offset = input.offset_from(token_start);
+
+    SourceSpan {
+        range: (input.current_token_start() - offset)..input.current_token_start(),
+    }
+}
+
+impl<'input> ParserError<Input<'input>> for ParseError {
+    type Inner = ParseError;
+
+    fn from_input(_input: &Input<'input>) -> Self {
+        ParseError::ctx()
+    }
+
+    fn into_inner(self) -> winnow::Result<Self::Inner, Self> {
+        Ok(self)
+    }
+
+    fn is_backtrack(&self) -> bool {
+        !self.is_fatal
+    }
+}
+
+#[derive(Debug)]
+pub struct ParsedTemplate {
+    tokens: Vec<TemplateToken>,
+}
+
+impl ParsedTemplate {
+    pub fn tokens(&self) -> &[TemplateToken] {
+        &self.tokens
+    }
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum TokenKind {
+    Content,
+    LeftDelim,
+    RightDelim,
+    TrimWhitespace,
+    WantsOutput,
+    Ident,
+    LeftArgList,
+    RightArgList,
+    ArgSeperator,
+    Whitespace,
+    Invalid,
+    ConditionalIf,
+    ConditionalElse,
+    For,
+    In,
+    End,
+    Literal(TokenLiteral),
+    Operator(TokenOperator),
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum TokenOperator {
+    Plus,
+    Minus,
+    Times,
+    Divide,
+    And,
+    Or,
+    Equal,
+    NotEqual,
+    Greater,
+    GreaterOrEqual,
+    Lesser,
+    LesserOrEqual,
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum TokenLiteral {
+    Bool(bool),
+    Integer(u64),
+}
+
+impl PartialEq<TokenKind> for TemplateToken {
+    fn eq(&self, other: &TokenKind) -> bool {
+        self.kind == *other
+    }
+}
+
+impl winnow::stream::ContainsToken<&'_ TemplateToken> for TokenKind {
+    fn contains_token(&self, token: &'_ TemplateToken) -> bool {
+        *self == token.kind
+    }
+}
+
+impl winnow::stream::ContainsToken<&'_ TemplateToken> for &'_ [TokenKind] {
+    fn contains_token(&self, token: &'_ TemplateToken) -> bool {
+        self.contains(&token.kind)
+    }
+}
+
+impl<const LEN: usize> winnow::stream::ContainsToken<&'_ TemplateToken> for &'_ [TokenKind; LEN] {
+    fn contains_token(&self, token: &'_ TemplateToken) -> bool {
+        self.contains(&token.kind)
+    }
+}
+
+impl<const LEN: usize> winnow::stream::ContainsToken<&'_ TemplateToken> for [TokenKind; LEN] {
+    fn contains_token(&self, token: &'_ TemplateToken) -> bool {
+        self.contains(&token.kind)
+    }
+}
+
+#[derive(Clone, PartialEq, Eq)]
+pub struct TemplateToken {
+    kind: TokenKind,
+    source: NomoInput,
+}
+
+impl std::fmt::Debug for TemplateToken {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "[{:?}]{:?}", self.kind(), self.source())
+    }
+}
+
+impl Location for TemplateToken {
+    fn previous_token_end(&self) -> usize {
+        NomoInput::get_range(&self.source).start
+    }
+
+    fn current_token_start(&self) -> usize {
+        NomoInput::get_range(&self.source).start
+    }
+}
+
+macro_rules! impl_token_kind_builders {
+    ($($name:ident => $kind:expr),+ $(,)?) => {
+        $(
+            fn $name(source: NomoInput) -> Self {
+                TemplateToken {
+                    kind: $kind,
+                    source,
+                }
+            }
+        )+
+    };
+}
+
+impl TemplateToken {
+    impl_token_kind_builders! {
+        content => TokenKind::Content,
+        left_delim => TokenKind::LeftDelim,
+        right_delim => TokenKind::RightDelim,
+        trim_whitespace => TokenKind::TrimWhitespace,
+        wants_output => TokenKind::WantsOutput,
+        ident => TokenKind::Ident,
+        left_arg_list => TokenKind::LeftArgList,
+        right_arg_list => TokenKind::RightArgList,
+        arg_seperator => TokenKind::ArgSeperator,
+        whitespace => TokenKind::Whitespace,
+        invalid => TokenKind::Invalid,
+        conditional_if => TokenKind::ConditionalIf,
+        conditional_else => TokenKind::ConditionalElse,
+        keyword_for => TokenKind::For,
+        keyword_in => TokenKind::In,
+        end => TokenKind::End,
+    }
+
+    pub fn literal(literal: TokenLiteral, source: NomoInput) -> Self {
+        TemplateToken {
+            kind: TokenKind::Literal(literal),
+            source,
+        }
+    }
+
+    pub fn operator(operator: TokenOperator, source: NomoInput) -> Self {
+        TemplateToken {
+            kind: TokenKind::Operator(operator),
+            source,
+        }
+    }
+
+    pub fn kind(&self) -> TokenKind {
+        self.kind
+    }
+
+    pub fn source(&self) -> NomoInput {
+        self.source.clone()
+    }
+}
+
+pub fn parse(input: NomoInput) -> Result<ParsedTemplate, ParseFailure> {
+    let (_remaining, val, errors) =
+        parse_tokens.recoverable_parse(LocatingSlice::new(input.clone()));
+
+    if errors.is_empty()
+        && let Some(val) = val
+    {
+        Ok(ParsedTemplate { tokens: val })
+    } else {
+        Err(ParseFailure::from_errors(errors, input))
+    }
+}
+
+fn parse_tokens<'input>(input: &mut Input<'input>) -> PResult<'input, Vec<TemplateToken>> {
+    repeat_till(0.., alt((parse_interpolate, parse_content)), eof)
+        .map(|(v, _): (Vec<_>, _)| v.into_iter().flatten().collect())
+        .parse_next(input)
+}
+
+fn parse_content<'input>(input: &mut Input<'input>) -> PResult<'input, Vec<TemplateToken>> {
+    alt((
+        repeat_till(1.., any, peek((multispace0, "{{"))).map(|((), _)| ()),
+        rest.void(),
+    ))
+    .take()
+    .map(TemplateToken::content)
+    .map(|v| vec![v])
+    .parse_next(input)
+}
+
+fn parse_interpolate<'input>(input: &mut Input<'input>) -> PResult<'input, Vec<TemplateToken>> {
+    let prev_whitespace = opt(parse_whitespace).parse_next(input)?;
+    let left_delim = "{{".map(TemplateToken::left_delim).parse_next(input)?;
+    let left_trim = opt("-".map(TemplateToken::trim_whitespace)).parse_next(input)?;
+    let wants_output = opt("=".map(TemplateToken::wants_output)).parse_next(input)?;
+
+    let get_tokens = repeat_till(1.., parse_block_token, peek(preceded(opt("-"), "}}")));
+    let recover = take_until(0.., "}}").void();
+
+    let (inside_tokens, _): (Vec<_>, _) = get_tokens
+        .resume_after(recover)
+        .with_taken()
+        .map(|(val, taken)| {
+            val.unwrap_or_else(|| (vec![TemplateToken::invalid(taken)], NomoInput::from("")))
+        })
+        .parse_next(input)?;
+
+    let right_trim = opt("-".map(TemplateToken::trim_whitespace)).parse_next(input)?;
+    let right_delim = "}}".map(TemplateToken::right_delim).parse_next(input)?;
+    let post_whitespace = opt(parse_whitespace).parse_next(input)?;
+
+    let mut tokens = vec![];
+    tokens.extend(prev_whitespace);
+    tokens.push(left_delim);
+    tokens.extend(left_trim);
+    tokens.extend(wants_output);
+    tokens.extend(inside_tokens);
+    tokens.extend(right_trim);
+    tokens.push(right_delim);
+    tokens.extend(post_whitespace);
+
+    Ok(tokens)
+}
+
+fn parse_block_token<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace(
+        "parse_block_token",
+        alt((
+            parse_ident,
+            parse_function,
+            parse_keyword,
+            parse_whitespace,
+            parse_operator,
+        )),
+    )
+    .parse_next(input)
+}
+
+fn parse_literal<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace(
+        "parse_literal",
+        alt((parse_boolean, parse_number))
+            .with_taken()
+            .map(|(lit, span)| TemplateToken::literal(lit, span)),
+    )
+    .parse_next(input)
+}
+
+fn parse_number<'input>(input: &mut Input<'input>) -> PResult<'input, TokenLiteral> {
+    digit1
+        .verify_map(|digits: NomoInput| digits.parse::<u64>().ok())
+        .map(TokenLiteral::Integer)
+        .parse_next(input)
+}
+
+fn parse_boolean<'input>(input: &mut Input<'input>) -> PResult<'input, TokenLiteral> {
+    alt((
+        "true".value(TokenLiteral::Bool(true)),
+        "false".value(TokenLiteral::Bool(false)),
+    ))
+    .parse_next(input)
+}
+
+fn parse_condition_if<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace(
+        "parse_condition_if",
+        "if".map(TemplateToken::conditional_if),
+    )
+    .parse_next(input)
+}
+
+fn parse_condition_else<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace(
+        "parse_condition_else",
+        "else".map(TemplateToken::conditional_else),
+    )
+    .parse_next(input)
+}
+
+fn parse_end<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace("parse_end", "end".map(TemplateToken::end)).parse_next(input)
+}
+
+fn parse_for<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace("parse_for", "for".map(TemplateToken::keyword_for)).parse_next(input)
+}
+
+fn parse_in<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace("parse_in", "in".map(TemplateToken::keyword_in)).parse_next(input)
+}
+
+fn parse_keyword<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    alt((
+        terminated(parse_literal, ident_terminator_check),
+        terminated(parse_condition_if, ident_terminator_check),
+        terminated(parse_condition_else, ident_terminator_check),
+        terminated(parse_for, ident_terminator_check),
+        terminated(parse_in, ident_terminator_check),
+        terminated(parse_end, ident_terminator_check),
+    ))
+    .parse_next(input)
+}
+
+fn parse_whitespace<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace(
+        "parse_whitespace",
+        multispace1.map(TemplateToken::whitespace),
+    )
+    .parse_next(input)
+}
+
+fn parse_function<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace(
+        "parse_function",
+        alt((
+            "(".map(TemplateToken::left_arg_list),
+            ")".map(TemplateToken::right_arg_list),
+            ",".map(TemplateToken::arg_seperator),
+        )),
+    )
+    .parse_next(input)
+}
+
+fn parse_ident<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    resume_after_cut(
+        terminated(
+            ident.map(TemplateToken::ident),
+            cut_err(ident_terminator_check),
+        )
+        .context(
+            ParseError::ctx()
+                .msg("Invalid variable identifier")
+                .help("valid variable identifiers are alphanumeric"),
+        ),
+        bad_ident,
+    )
+    .with_taken()
+    .map(|(val, taken)| val.unwrap_or(TemplateToken::invalid(taken)))
+    .parse_next(input)
+}
+
+fn parse_operator<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    let (operator, source) = trace(
+        "operator",
+        dispatch! {any;
+            '+' => empty.value(TokenOperator::Plus),
+            '-' => empty.value(TokenOperator::Minus),
+            '*' => empty.value(TokenOperator::Times),
+            '/' => empty.value(TokenOperator::Divide),
+            '&' => alt((
+                "&".value(TokenOperator::And),
+                cut_err(fail),
+            )),
+            '|' => alt((
+                "|".value(TokenOperator::Or),
+                cut_err(fail),
+            )),
+            '<' => alt((
+                "=".value(TokenOperator::LesserOrEqual),
+                empty.value(TokenOperator::Lesser),
+            )),
+            '>' => alt((
+                "=".value(TokenOperator::GreaterOrEqual),
+                empty.value(TokenOperator::Greater),
+            )),
+            '!' => alt((
+                "=".value(TokenOperator::NotEqual),
+                cut_err(fail),
+            )),
+            '=' => alt((
+                "=".value(TokenOperator::Equal),
+                cut_err(fail),
+            )),
+            _ => fail,
+        },
+    )
+    .with_taken()
+    .parse_next(input)?;
+
+    Ok(TemplateToken::operator(operator, source))
+}
+
+fn ident<'input>(input: &mut Input<'input>) -> PResult<'input, NomoInput> {
+    peek(not(parse_keyword))
+        .context(ParseError::ctx().msg("Expected an ident, but found a literal instead"))
+        .parse_next(input)?;
+
+    let literal_start = alt((alpha1, "_"));
+
+    (
+        literal_start,
+        take_while(0.., |c: char| c.is_alphanumeric() || "_".contains(c)),
+    )
+        .take()
+        .parse_next(input)
+}
+
+fn bad_ident<'input>(input: &mut Input<'input>) -> PResult<'input, ()> {
+    repeat_till(1.., any, ident_terminator_check)
+        .map(|((), _)| ())
+        .parse_next(input)
+}
+
+fn ident_terminator_check<'input>(input: &mut Input<'input>) -> PResult<'input, ()> {
+    peek(ident_terminator).parse_next(input)
+}
+
+fn ident_terminator<'input>(input: &mut Input<'input>) -> PResult<'input, ()> {
+    alt((
+        eof.void(),
+        one_of(('{', '}')).void(),
+        one_of(('(', ',', ')')).void(),
+        one_of((' ', '\t', '\r', '\n')).void(),
+    ))
+    .parse_next(input)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::lexer::parse;
+
+    #[test]
+    fn parse_simple() {
+        let input = "Hello There";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [Content]"Hello There" (0..11),
+                ],
+            },
+        )
+        "#);
+    }
+
+    #[test]
+    fn parse_interpolate() {
+        let input = "Hello {{ there }}";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [Content]"Hello" (0..5),
+                    [Whitespace]" " (5..6),
+                    [LeftDelim]"{{" (6..8),
+                    [Whitespace]" " (8..9),
+                    [Ident]"there" (9..14),
+                    [Whitespace]" " (14..15),
+                    [RightDelim]"}}" (15..17),
+                ],
+            },
+        )
+        "#);
+    }
+
+    #[test]
+    fn parse_interpolate_bad() {
+        let input = "Hello {{ the2re }} {{ the@re }}";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Err(
+            ParseFailure {
+                input: "Hello {{ the2re }} {{ the@re }}",
+                errors: [
+                    ParseError {
+                        message: Some(
+                            "Invalid variable identifier",
+                        ),
+                        help: Some(
+                            "valid variable identifiers are alphanumeric",
+                        ),
+                        span: Some(
+                            SourceSpan {
+                                range: 22..28,
+                            },
+                        ),
+                        is_fatal: true,
+                    },
+                ],
+            },
+        )
+        "#);
+
+        let error = output.unwrap_err();
+
+        insta::assert_snapshot!(error.to_report());
+    }
+
+    #[test]
+    fn parse_simple_condition() {
+        let input = "{{ if true }} Hello! {{ else }} Bye {{ end }}";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [LeftDelim]"{{" (0..2),
+                    [Whitespace]" " (2..3),
+                    [ConditionalIf]"if" (3..5),
+                    [Whitespace]" " (5..6),
+                    [Literal(Bool(true))]"true" (6..10),
+                    [Whitespace]" " (10..11),
+                    [RightDelim]"}}" (11..13),
+                    [Whitespace]" " (13..14),
+                    [Content]"Hello!" (14..20),
+                    [Whitespace]" " (20..21),
+                    [LeftDelim]"{{" (21..23),
+                    [Whitespace]" " (23..24),
+                    [ConditionalElse]"else" (24..28),
+                    [Whitespace]" " (28..29),
+                    [RightDelim]"}}" (29..31),
+                    [Whitespace]" " (31..32),
+                    [Content]"Bye" (32..35),
+                    [Whitespace]" " (35..36),
+                    [LeftDelim]"{{" (36..38),
+                    [Whitespace]" " (38..39),
+                    [End]"end" (39..42),
+                    [Whitespace]" " (42..43),
+                    [RightDelim]"}}" (43..45),
+                ],
+            },
+        )
+        "#);
+    }
+
+    #[test]
+    fn parse_trim_whitespace() {
+        let input = "\n\n{{-= hello -}} \n\n";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [Whitespace]"\n\n" (0..2),
+                    [LeftDelim]"{{" (2..4),
+                    [TrimWhitespace]"-" (4..5),
+                    [WantsOutput]"=" (5..6),
+                    [Whitespace]" " (6..7),
+                    [Ident]"hello" (7..12),
+                    [Whitespace]" " (12..13),
+                    [TrimWhitespace]"-" (13..14),
+                    [RightDelim]"}}" (14..16),
+                    [Whitespace]" \n\n" (16..19),
+                ],
+            },
+        )
+        "#);
+    }
+
+    #[test]
+    fn parse_for_loop() {
+        let input = "{{ for value in array }} Hi: {{= value }} {{ end }}";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [LeftDelim]"{{" (0..2),
+                    [Whitespace]" " (2..3),
+                    [For]"for" (3..6),
+                    [Whitespace]" " (6..7),
+                    [Ident]"value" (7..12),
+                    [Whitespace]" " (12..13),
+                    [In]"in" (13..15),
+                    [Whitespace]" " (15..16),
+                    [Ident]"array" (16..21),
+                    [Whitespace]" " (21..22),
+                    [RightDelim]"}}" (22..24),
+                    [Whitespace]" " (24..25),
+                    [Content]"Hi:" (25..28),
+                    [Whitespace]" " (28..29),
+                    [LeftDelim]"{{" (29..31),
+                    [WantsOutput]"=" (31..32),
+                    [Whitespace]" " (32..33),
+                    [Ident]"value" (33..38),
+                    [Whitespace]" " (38..39),
+                    [RightDelim]"}}" (39..41),
+                    [Whitespace]" " (41..42),
+                    [LeftDelim]"{{" (42..44),
+                    [Whitespace]" " (44..45),
+                    [End]"end" (45..48),
+                    [Whitespace]" " (48..49),
+                    [RightDelim]"}}" (49..51),
+                ],
+            },
+        )
+        "#);
+    }
+
+    #[test]
+    fn parse_operations() {
+        let input = "{{= 5 * 14 + 3 / 2 - 1 }}{{ if foo && bar || baz && 2 != 3 || 4 > 2 || 43 <= 5 }}{{ end }}";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [LeftDelim]"{{" (0..2),
+                    [WantsOutput]"=" (2..3),
+                    [Whitespace]" " (3..4),
+                    [Literal(Integer(5))]"5" (4..5),
+                    [Whitespace]" " (5..6),
+                    [Operator(Times)]"*" (6..7),
+                    [Whitespace]" " (7..8),
+                    [Literal(Integer(14))]"14" (8..10),
+                    [Whitespace]" " (10..11),
+                    [Operator(Plus)]"+" (11..12),
+                    [Whitespace]" " (12..13),
+                    [Literal(Integer(3))]"3" (13..14),
+                    [Whitespace]" " (14..15),
+                    [Operator(Divide)]"/" (15..16),
+                    [Whitespace]" " (16..17),
+                    [Literal(Integer(2))]"2" (17..18),
+                    [Whitespace]" " (18..19),
+                    [Operator(Minus)]"-" (19..20),
+                    [Whitespace]" " (20..21),
+                    [Literal(Integer(1))]"1" (21..22),
+                    [Whitespace]" " (22..23),
+                    [RightDelim]"}}" (23..25),
+                    [LeftDelim]"{{" (25..27),
+                    [Whitespace]" " (27..28),
+                    [ConditionalIf]"if" (28..30),
+                    [Whitespace]" " (30..31),
+                    [Ident]"foo" (31..34),
+                    [Whitespace]" " (34..35),
+                    [Operator(And)]"&&" (35..37),
+                    [Whitespace]" " (37..38),
+                    [Ident]"bar" (38..41),
+                    [Whitespace]" " (41..42),
+                    [Operator(Or)]"||" (42..44),
+                    [Whitespace]" " (44..45),
+                    [Ident]"baz" (45..48),
+                    [Whitespace]" " (48..49),
+                    [Operator(And)]"&&" (49..51),
+                    [Whitespace]" " (51..52),
+                    [Literal(Integer(2))]"2" (52..53),
+                    [Whitespace]" " (53..54),
+                    [Operator(NotEqual)]"!=" (54..56),
+                    [Whitespace]" " (56..57),
+                    [Literal(Integer(3))]"3" (57..58),
+                    [Whitespace]" " (58..59),
+                    [Operator(Or)]"||" (59..61),
+                    [Whitespace]" " (61..62),
+                    [Literal(Integer(4))]"4" (62..63),
+                    [Whitespace]" " (63..64),
+                    [Operator(Greater)]">" (64..65),
+                    [Whitespace]" " (65..66),
+                    [Literal(Integer(2))]"2" (66..67),
+                    [Whitespace]" " (67..68),
+                    [Operator(Or)]"||" (68..70),
+                    [Whitespace]" " (70..71),
+                    [Literal(Integer(43))]"43" (71..73),
+                    [Whitespace]" " (73..74),
+                    [Operator(LesserOrEqual)]"<=" (74..76),
+                    [Whitespace]" " (76..77),
+                    [Literal(Integer(5))]"5" (77..78),
+                    [Whitespace]" " (78..79),
+                    [RightDelim]"}}" (79..81),
+                    [LeftDelim]"{{" (81..83),
+                    [Whitespace]" " (83..84),
+                    [End]"end" (84..87),
+                    [Whitespace]" " (87..88),
+                    [RightDelim]"}}" (88..90),
+                ],
+            },
+        )
+        "#);
+    }
+
+    #[test]
+    fn parse_function() {
+        let input = "{{= foo(23, 4, 3 * 5) }}";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [LeftDelim]"{{" (0..2),
+                    [WantsOutput]"=" (2..3),
+                    [Whitespace]" " (3..4),
+                    [Ident]"foo" (4..7),
+                    [LeftArgList]"(" (7..8),
+                    [Literal(Integer(23))]"23" (8..10),
+                    [ArgSeperator]"," (10..11),
+                    [Whitespace]" " (11..12),
+                    [Literal(Integer(4))]"4" (12..13),
+                    [ArgSeperator]"," (13..14),
+                    [Whitespace]" " (14..15),
+                    [Literal(Integer(3))]"3" (15..16),
+                    [Whitespace]" " (16..17),
+                    [Operator(Times)]"*" (17..18),
+                    [Whitespace]" " (18..19),
+                    [Literal(Integer(5))]"5" (19..20),
+                    [RightArgList]")" (20..21),
+                    [Whitespace]" " (21..22),
+                    [RightDelim]"}}" (22..24),
+                ],
+            },
+        )
+        "#);
+    }
+}

src/lexer/snapshots/nomo__lexer__tests__parse_interpolate_bad-2.snap

@@ -1,5 +1,5 @@
 ---
-source: src/parser/mod.rs
+source: src/lexer/mod.rs
 expression: error.to_report()
 ---
 error: Invalid variable identifier

src/lib.rs

@@ -4,15 +4,17 @@ use displaydoc::Display;
 use thiserror::Error;
 
 use crate::emit::VMInstructions;
+use crate::functions::FunctionMap;
 use crate::input::NomoInput;
 use crate::value::NomoValue;
 use crate::value::NomoValueError;
 
-pub mod ast;
+pub mod parser;
 pub mod emit;
 pub mod eval;
+pub mod functions;
 pub mod input;
-pub mod parser;
+pub mod lexer;
 pub mod value;
 
 #[derive(Debug, Error, Display)]
@@ -20,12 +22,12 @@ pub enum NomoError {
     /// Could not parse the given template
     ParseError {
         #[from]
-        source: parser::ParseFailure,
+        source: lexer::ParseFailure,
     },
     /// Invalid Template
     AstError {
         #[from]
-        source: ast::AstFailure,
+        source: parser::AstFailure,
     },
 
     /// An error occurred while evaluating
@@ -40,6 +42,7 @@ pub enum NomoError {
 
 pub struct Nomo {
     templates: HashMap<String, Template>,
+    function_map: FunctionMap,
 }
 
 impl Default for Nomo {
@@ -52,6 +55,7 @@ impl Nomo {
     pub fn new() -> Nomo {
         Nomo {
             templates: HashMap::new(),
+            function_map: FunctionMap::default(),
         }
     }
 
@@ -61,8 +65,8 @@ impl Nomo {
         value: impl Into<NomoInput>,
     ) -> Result<(), NomoError> {
         let source = value.into();
-        let parse = parser::parse(source.clone())?;
-        let ast = ast::parse(parse.tokens())?;
+        let parse = lexer::parse(source.clone())?;
+        let ast = parser::parse(parse.tokens())?;
 
         let instructions = emit::emit_machine(ast);
 
@@ -78,7 +82,7 @@ impl Nomo {
             .get(name)
             .ok_or_else(|| NomoError::UnknownTemplate(name.to_string()))?;
 
-        let res = eval::execute(&template.instructions, ctx)?;
+        let res = eval::execute(&self.function_map, &template.instructions, ctx)?;
 
         Ok(res)
     }

src/parser/snapshots/nomo__parser__tests__check_for_loop.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast
 ---
 TemplateAst {

src/parser/snapshots/nomo__parser__tests__check_function_call.snap

@@ -0,0 +1,49 @@
+---
+source: src/parser/mod.rs
+expression: ast
+---
+TemplateAst {
+    root: [
+        Interpolation {
+            prev_whitespace_content: None,
+            expression: FunctionCall {
+                name: [Ident]"foo" (4..7),
+                args: [
+                    Operation {
+                        op: Times,
+                        lhs: Literal {
+                            source: [Literal(Integer(2))]"2" (8..9),
+                            value: Integer {
+                                value: 2,
+                            },
+                        },
+                        rhs: Literal {
+                            source: [Literal(Integer(3))]"3" (12..13),
+                            value: Integer {
+                                value: 3,
+                            },
+                        },
+                    },
+                    FunctionCall {
+                        name: [Ident]"bar" (15..18),
+                        args: [
+                            Operation {
+                                op: Plus,
+                                lhs: Literal {
+                                    source: [Literal(Integer(2))]"2" (19..20),
+                                    value: Integer {
+                                        value: 2,
+                                    },
+                                },
+                                rhs: VariableAccess(
+                                    [Ident]"baz" (23..26),
+                                ),
+                            },
+                        ],
+                    },
+                ],
+            },
+            post_whitespace_content: None,
+        },
+    ],
+}

src/parser/snapshots/nomo__parser__tests__check_if_else.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast
 ---
 TemplateAst {

src/parser/snapshots/nomo__parser__tests__check_if_else_if.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast
 ---
 TemplateAst {

src/parser/snapshots/nomo__parser__tests__check_invalid_action.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast.to_report(input)
 ---
 error: Standlone action block

src/parser/snapshots/nomo__parser__tests__check_logical_expression.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast
 ---
 TemplateAst {

src/parser/snapshots/nomo__parser__tests__check_math_expression.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast
 ---
 TemplateAst {

src/parser/snapshots/nomo__parser__tests__check_trim_whitespace.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast
 ---
 TemplateAst {

src/parser/snapshots/nomo__parser__tests__simple_if_ast.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: ast
 ---
 TemplateAst {

src/parser/snapshots/nomo__parser__tests__simple_if_tokens.snap

@@ -1,5 +1,5 @@
 ---
-source: src/ast/mod.rs
+source: src/parser/mod.rs
 expression: parsed
 ---
 ParsedTemplate {

src/value.rs

@@ -5,8 +5,6 @@ use std::collections::BTreeMap;
 use displaydoc::Display;
 use thiserror::Error;
 
-use crate::Nomo;
-
 #[derive(Clone)]
 pub enum NomoValue {
     String {
@@ -312,6 +310,18 @@ impl From<&'static str> for NomoValue {
     }
 }
 
+impl From<u64> for NomoValue {
+    fn from(val: u64) -> Self {
+        NomoValue::Integer { value: val }
+    }
+}
+
+impl From<i64> for NomoValue {
+    fn from(val: i64) -> Self {
+        NomoValue::SignedInteger { value: val }
+    }
+}
+
 impl<V> From<Vec<V>> for NomoValue
 where
     V: Into<NomoValue>,
@@ -357,11 +367,43 @@ where
     }
 }
 
-#[cfg(feature = "serde_json")]
 #[derive(Debug, Error, Display)]
-/// Could not transform value to [`NomoValue`]
+/// Could not transform value to/from [`NomoValue`]
 pub struct NomoValueError;
 
+impl TryFrom<NomoValue> for String {
+    type Error = NomoValueError;
+
+    fn try_from(value: NomoValue) -> Result<Self, Self::Error> {
+        match value {
+            NomoValue::String { value } => Ok(value.to_string()),
+            _ => Err(NomoValueError),
+        }
+    }
+}
+
+impl TryFrom<NomoValue> for i64 {
+    type Error = NomoValueError;
+
+    fn try_from(value: NomoValue) -> Result<Self, Self::Error> {
+        match value {
+            NomoValue::SignedInteger { value } => Ok(value),
+            _ => Err(NomoValueError),
+        }
+    }
+}
+
+impl TryFrom<NomoValue> for u64 {
+    type Error = NomoValueError;
+
+    fn try_from(value: NomoValue) -> Result<Self, Self::Error> {
+        match value {
+            NomoValue::Integer { value } => Ok(value),
+            _ => Err(NomoValueError),
+        }
+    }
+}
+
 #[cfg(feature = "serde_json")]
 impl TryFrom<serde_json::Value> for NomoValue {
     type Error = NomoValueError;

tests/checks.rs

@@ -5,11 +5,11 @@ fn check_files() {
     for file in files {
         let input = std::fs::read_to_string(file.unwrap().path()).unwrap();
 
-        let Ok(parsed) = nomo::parser::parse(input.into()) else {
+        let Ok(parsed) = nomo::lexer::parse(input.into()) else {
             continue;
         };
 
-        let Ok(ast) = nomo::ast::parse(parsed.tokens()) else {
+        let Ok(ast) = nomo::parser::parse(parsed.tokens()) else {
             continue;
         };
 

tests/file_tests.rs

@@ -2,6 +2,7 @@ use std::collections::HashMap;
 use std::path::Path;
 
 use nomo::Context;
+use nomo::functions::FunctionMap;
 
 test_each_file::test_each_path! { for ["nomo"] in "./tests/cases/" as cases => check_for_input }
 
@@ -38,13 +39,13 @@ fn check_for_input([path]: [&Path; 1]) {
         context.try_insert(k, v).unwrap();
     }
 
-    let parsed = nomo::parser::parse(input.into()).unwrap();
+    let parsed = nomo::lexer::parse(input.into()).unwrap();
 
     let _guard = settings.bind_to_scope();
 
     insta::assert_debug_snapshot!(format!("{basename}.1-parsed"), parsed);
 
-    let ast = match nomo::ast::parse(parsed.tokens()) {
+    let ast = match nomo::parser::parse(parsed.tokens()) {
         Ok(ast) => ast,
         Err(err) => {
             eprintln!("{}", err.to_report(input));
@@ -58,7 +59,7 @@ fn check_for_input([path]: [&Path; 1]) {
 
     insta::assert_debug_snapshot!(format!("{basename}.3-instructions"), emit);
 
-    let output = nomo::eval::execute(&emit, &context).unwrap();
+    let output = nomo::eval::execute(&FunctionMap::default(), &emit, &context).unwrap();
 
     insta::assert_debug_snapshot!(format!("{basename}.4-output"), output);
 }