From b3318e5f246f5a382ca87b9f98e536d8248b3f12 Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Fri, 6 May 2022 00:26:20 -0400
Subject: [PATCH] feat: most of the constants and better space skipping

---
 Cargo.lock          |  7 ++++
 Cargo.toml          |  1 +
 example/plutus-core |  2 +-
 src/parser.rs       | 87 ++++++++++++++++++++++++++++++++++-----------
 4 files changed, 75 insertions(+), 22 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 12d30458..b70139f7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -107,6 +107,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
 [[package]]
 name = "indexmap"
 version = "1.8.1"
@@ -142,6 +148,7 @@ dependencies = [
  "anyhow",
  "clap",
  "combine",
+ "hex",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 5793c20b..3118c9ee 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,3 +9,4 @@ edition = "2021"
 anyhow = "1.0.57"
 clap = { version = "3.1.14", features = ["derive"] }
 combine = "4.6.4"
+hex = "0.4.3"
diff --git a/example/plutus-core b/example/plutus-core
index 53a1833e..f060918b 100644
--- a/example/plutus-core
+++ b/example/plutus-core
@@ -1,3 +1,3 @@
 (program 1.0.0
-    (con integer 4)
+    (con bool False)
 )
\ No newline at end of file
diff --git a/src/parser.rs b/src/parser.rs
index 23327212..10523e34 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,14 +1,14 @@
 use combine::{
-    between, many1,
-    parser::char::{digit, spaces, string},
-    token, ParseError, Parser, Stream,
+    attempt, between, choice, many1,
+    parser::char::{alpha_num, digit, hex_digit, space, spaces, string},
+    skip_many1, token, EasyParser, ParseError, Parser, Stream,
 };
 
 use crate::ast::{Constant, Program, Term};
 
 pub fn program(src: &str) -> anyhow::Result<Program> {
     let mut parser = program_();
-    let result = parser.parse(src);
+    let result = parser.easy_parse(src);
 
     match result {
         Ok((program, _)) => Ok(program),
@@ -52,7 +52,12 @@ where
     Input: Stream<Token = char>,
     Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
 {
-    between(token('('), token(')'), constant().or(delay())).skip(spaces())
+    between(
+        token('('),
+        token(')'),
+        choice((attempt(constant()), attempt(delay()), attempt(force()))),
+    )
+    .skip(spaces())
 }
 
 parser! {
@@ -69,19 +74,36 @@ where
     Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
 {
     string("delay")
-        .skip(spaces())
+        .with(skip_many1(space()))
         .with(term_())
         .map(|term| Term::Delay(Box::new(term)))
 }
 
+pub fn force<Input>() -> impl Parser<Input, Output = Term>
+where
+    Input: Stream<Token = char>,
+    Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
+{
+    string("force")
+        .with(skip_many1(space()))
+        .with(term_())
+        .map(|term| Term::Force(Box::new(term)))
+}
+
 pub fn constant<Input>() -> impl Parser<Input, Output = Term>
 where
     Input: Stream<Token = char>,
     Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
 {
     string("con")
-        .skip(spaces())
-        .with(constant_integer().or(unit()).or(constant_bool()))
+        .with(skip_many1(space()))
+        .with(choice((
+            attempt(constant_integer()),
+            attempt(constant_bytestring()),
+            attempt(constant_string()),
+            attempt(constant_unit()),
+            attempt(constant_bool()),
+        )))
         .map(Term::Constant)
 }
 
@@ -91,33 +113,56 @@ where
     Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
 {
     string("integer")
-        .skip(spaces())
+        .with(skip_many1(space()))
         .with(many1(digit()))
         .map(|d: String| Constant::Integer(d.parse::<i64>().unwrap()))
 }
 
+pub fn constant_bytestring<Input>() -> impl Parser<Input, Output = Constant>
+where
+    Input: Stream<Token = char>,
+    Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
+{
+    string("bytestring")
+        .with(skip_many1(space()))
+        .with(token('#'))
+        .with(many1(hex_digit()))
+        .map(|b: String| Constant::ByteString(hex::decode(b).unwrap()))
+}
+
+pub fn constant_string<Input>() -> impl Parser<Input, Output = Constant>
+where
+    Input: Stream<Token = char>,
+    Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
+{
+    string("string")
+        .with(skip_many1(space()))
+        .with(between(token('"'), token('"'), many1(alpha_num())))
+        .map(Constant::String)
+}
+
+pub fn constant_unit<Input>() -> impl Parser<Input, Output = Constant>
+where
+    Input: Stream<Token = char>,
+    Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
+{
+    string("unit")
+        .with(skip_many1(space()))
+        .with(string("()"))
+        .map(|_| Constant::Unit)
+}
+
 pub fn constant_bool<Input>() -> impl Parser<Input, Output = Constant>
 where
     Input: Stream<Token = char>,
     Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
 {
     string("bool")
-        .skip(spaces())
+        .with(skip_many1(space()))
         .with(string("True").or(string("False")))
         .map(|b| Constant::Bool(b == "True"))
 }
 
-pub fn unit<Input>() -> impl Parser<Input, Output = Constant>
-where
-    Input: Stream<Token = char>,
-    Input::Error: ParseError<Input::Token, Input::Range, Input::Position>,
-{
-    string("unit")
-        .skip(spaces())
-        .with(string("()"))
-        .map(|_| Constant::Unit)
-}
-
 #[cfg(test)]
 mod test {
     use combine::Parser;