Improve tvf! macro for negative numerical values

prosa_macros/Cargo.toml

@@ -20,6 +20,8 @@ syn = { version = "3", features = ["full"] }
 quote = "1"
 proc-macro2 = "1"
 chrono.workspace = true
+thiserror.workspace = true
+num-traits = "0.2"
 
 [dev-dependencies]
 bytes.workspace = true

prosa_macros/src/tvf.rs

@@ -1,46 +1,70 @@
-mod buffer;
-mod literal;
-mod value;
+/// Structures to properly identify the TVF fields to generate
+pub(crate) mod expr;
 
-use buffer::{generate_list, generate_map};
+/// Consume tvf! macro tokens and generate corresponding tree structure of expressions
+pub(crate) mod parser;
+
+/// Convert the expressions into tokens to be passed to the compiler
+pub(crate) mod tokens;
+
+use crate::tvf::{parser::TvfParser, tokens::buffer_to_tokens};
 use proc_macro2::{Delimiter, TokenStream, TokenTree};
-use syn::Error;
+use quote::quote;
+use syn::spanned::Spanned;
 
-pub(crate) fn gen_tvf_impl(input: TokenStream) -> Result<TokenStream, Error> {
+pub(crate) fn gen_tvf_impl(input: TokenStream) -> Result<TokenStream, syn::Error> {
     // Process the token tree
+    let span = input.span();
     let mut tokens = input.into_iter();
 
     // The first token must be the buffer type used
     let buffer_type = if let Some(TokenTree::Ident(buffer_type)) = tokens.next() {
         buffer_type
     } else {
-        return Err(Error::new_spanned(
-            TokenStream::new(),
+        return Err(syn::Error::new(
+            span,
             "First argument must be a type identifier",
         ));
     };
 
     // The second token must be the content enclosed in {} or []
-    let result = if let Some(TokenTree::Group(content)) = tokens.next() {
-        match content.delimiter() {
-            Delimiter::Brace => generate_map(&buffer_type, &content),
-            Delimiter::Bracket => generate_list(&buffer_type, &content),
-            _ => Err(Error::new_spanned(
-                content,
-                "Invalid delimiter, expected {} or []",
-            )),
+    let output = if let Some(TokenTree::Group(group)) = tokens.next() {
+        match group.delimiter() {
+            Delimiter::Brace => {
+                let mut parser = TvfParser::new(group.stream(), true);
+                let exprs = parser.collect_expr()?;
+                buffer_to_tokens(&buffer_type, &exprs)?
+            }
+            Delimiter::Bracket => {
+                let mut parser = TvfParser::new(group.stream(), false);
+                let exprs = parser.collect_expr()?;
+                buffer_to_tokens(&buffer_type, &exprs)?
+            }
+            _ => {
+                return Err(syn::Error::new(
+                    span,
+                    "Invalid delimiter, expected {} or []",
+                ));
+            }
         }
     } else {
-        Err(Error::new_spanned(
-            TokenStream::new(),
+        return Err(syn::Error::new(
+            span,
             "Second argument must be the content enclosed in {} or []",
-        ))
+        ));
     };
 
     // Raise an error on any extra tokens
     if let Some(token) = tokens.next() {
-        return Err(Error::new_spanned(token, "Unexpected token"));
+        return Err(syn::Error::new_spanned(token, "Unexpected token"));
     }
 
-    result
+    Ok(quote![
+        {
+            use ::prosa_utils::msg::tvf as __tvf;
+            use ::prosa_utils::msg::bytes as __bytes;
+            use ::prosa_utils::msg::chrono as __chrono;
+            #output
+        }
+    ])
 }

prosa_macros/src/tvf/expr.rs

@@ -0,0 +1,137 @@
+use chrono::{NaiveDate, NaiveDateTime};
+use proc_macro2::{Span, TokenStream};
+use syn::spanned::Spanned;
+
+/// Define a field expression which includes the following elements
+/// - a target field identifier
+/// - a modifier (unary operator)
+/// - a literal / variable / rust-expression
+/// - a implicit or explicit target type
+pub(crate) struct TvfExpr {
+    /// Field identifier to use
+    pub id: TvfId,
+
+    /// Modifier for the value
+    pub modifier: Modifier,
+
+    /// Value to use for the field
+    pub value: TvfValue,
+
+    /// Output type to insert the field in the buffer
+    pub explicit_type: Option<TvfType>,
+}
+
+/// Identifier of a field
+pub(crate) enum TvfId {
+    /// We directly have an integer value
+    Int(usize),
+
+    /// Identifier of a variable
+    Ident(syn::Ident),
+
+    /// Rust expression (surrounded by parenthesis)
+    Expr(TokenStream),
+}
+
+/// Define a value to insert into the buffer
+pub(crate) enum TvfValue {
+    /// Simple literal which can be used to implicitely identify the type of the value
+    Lit(syn::Lit),
+
+    /// Identifier of a variable
+    Ident(syn::Ident),
+
+    /// Rust expression (surrounded by parenthesis)
+    Expr(TokenStream),
+
+    /// Sub-buffer
+    Buffer(Vec<TvfExpr>, Span),
+}
+
+impl TvfValue {
+    pub(crate) fn span(&self) -> Span {
+        match self {
+            TvfValue::Lit(lit) => lit.span(),
+            TvfValue::Ident(ident) => ident.span(),
+            TvfValue::Expr(stream) => stream.span(),
+            TvfValue::Buffer(_, span) => *span,
+        }
+    }
+}
+
+/// The types that can be added to a TVF buffer
+#[repr(u8)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum TvfType {
+    Byte,
+    Signed,
+    Unsigned,
+    Float,
+    String,
+    Bytes,
+    Date,
+    DateTime,
+    Buffer,
+}
+
+/// Modifier for a value
+/// Usually a not for boolean or a minus sign for numbers, etc..
+#[repr(u8)]
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum Modifier {
+    /// No operator
+    #[default]
+    None,
+
+    /// + sign, results in no operator being added
+    Positive,
+
+    /// - sign, negate the following value
+    Negative,
+
+    /// logical not for boolean values
+    LogicalNot,
+
+    /// * dereference
+    Dereference,
+
+    /// & borrow
+    Borrow,
+}
+
+/// Simple sequence of bytes to serialize
+#[derive(Debug, Default, Clone)]
+pub(crate) struct Bytes(pub Vec<u8>);
+
+/// Values that have been identified
+pub(crate) enum Value<'e> {
+    Bool(bool),
+    Byte(u8),
+    Signed(i64),
+    Unsigned(u64),
+    Float(f64),
+    String(String),
+    Bytes(Bytes),
+    Date(NaiveDate),
+    DateTime(NaiveDateTime),
+    Buffer(&'e [TvfExpr]),
+}
+
+impl<'e> Value<'e> {
+    /// Process the TvfValue to identify its type
+    #[rustfmt::skip]
+    pub(crate) fn identify(&self) -> TvfType {
+        match self {
+            Self::Bool     (_) => TvfType::Byte,
+            Self::Byte     (_) => TvfType::Byte,
+            Self::Signed   (_) => TvfType::Signed,
+            Self::Unsigned (_) => TvfType::Unsigned,
+            Self::Float    (_) => TvfType::Float,
+            Self::String   (_) => TvfType::String,
+            Self::Bytes    (_) => TvfType::Bytes,
+            Self::Date     (_) => TvfType::Date,
+            Self::DateTime (_) => TvfType::DateTime,
+            Self::Buffer   (_) => TvfType::Buffer,
+        }
+    }
+}