Re-use memory with a free-list

- pointa, point now uses this instruction

.github/workflows/ci.yml

@@ -0,0 +1,16 @@
+name: MBLF CI
+
+on: [push]
+
+jobs:
+  build_and_format_and_test:
+    name: Rust project
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+      - run: cargo build --release
+      - run: cargo clippy -- -Dwarnings
+      - run: cargo test

Cargo.toml

@@ -2,8 +2,18 @@
 name = "mblf"
 version = "0.1.0"
 edition = "2018"
+description = """
+The MBLF-To-BF compiler written in Rust with Pest.
+MBLF is a programming language on top of the esoteric programming language Brainfuck
+"""
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+authors = ["Raymon Zutekouw <contact@raymon.dev>"]
+
+repository = "https://github.com/MBLF-Project/mblf"
+license = "MIT OR Apache-2.0"
+
+keywords = ["compiler", "mblf", "brainfuck", "pest"]
+categories = ["compilers", "command-line-utilities", "parser-implementations"]
 
 [dependencies]
 anyhow = "1.0.44"

LICENSE-APACHE

@@ -0,0 +1,201 @@
+Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
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+
+      "Legal Entity" shall mean the union of the acting entity and all
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+      direction or management of such entity, whether by contract or
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+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+
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+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright 2022 Raymon Zutekouw
+
+   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
+
+       http://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.

LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 Raymon Zutekouw
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,32 @@
+# MBLF
+
+<img src="https://avatars.githubusercontent.com/u/77209611?s=200&v=4" alt="MBLF-logo" width="100px" />
+
+MBLF is a programming language on top of the esoteric programming language Brainfuck.
+
+## Installation:
+
+The easiest option is with cargo (rust's package manager):
+`cargo install mblf`
+
+## Usage:
+
+If installed with cargo and it's in path:
+`mblf input_mblf_file output_bf_file`
+
+# License
+
+Licensed under either of
+
+- Apache License, Version 2.0
+  ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+- MIT license
+  ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+# Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
+dual licensed as above, without any additional terms or conditions.

src/grammars/mblf.pest

@@ -11,27 +11,26 @@ num            =_{ hexNum | decNum }
 constant       = { char | num }
 path           = { "\"" ~ (!"\"" ~ ANY)+ ~ "\"" }
 
-include        = { "#include" ~ path }
+include        =@{ "#include" ~ spacing+ ~ path }
 
-var            = { "var"      ~ variable }
-delvar         = { "delvar"   ~ variable }
+var            =@{ "var"      ~ spacing+ ~ variable }
+delvar         =@{ "delvar"   ~ spacing+ ~ variable }
 
-point          = { "point"    ~ variable }
-pointm         = { "pointm"   ~ variable }
+point          =@{ "point"    ~ spacing+ ~ variable }
+pointa         =@{ "pointa"   ~ spacing+ ~ num      }
+pointm         =@{ "pointm"   ~ spacing+ ~ variable }
 
-add            = { "add"      ~ constant }
-addb           = { "addb"     ~ constant }
-addv           = { "addv"     ~ variable }
+add            =@{ "add"      ~ spacing+ ~ constant }
+addv           =@{ "addv"     ~ spacing+ ~ variable }
 
-sub            = { "sub"      ~ constant }
-subb           = { "subb"     ~ constant }
-subv           = { "subv"     ~ variable }
+sub            =@{ "sub"      ~ spacing+ ~ constant }
+subv           =@{ "subv"     ~ spacing+ ~ variable }
 
-copy           = { "copy"     ~ variable }
-setz           = { "setz" }
+copy           =@{ "copy"     ~ spacing+ ~ variable }
+setz           =@{ "setz" }
 
-getchr         = { "getchr" }
-print          = { "print" }
+getchr         =@{ "getchr" }
+print          =@{ "print" }
 
 macaroo        =_{ include }
 instruction    =_{ macaroo
@@ -40,14 +39,13 @@ instruction    =_{ macaroo
                  | delvar
 
                  | point
+                 | pointa
                  | pointm
 
                  | add
-                 | addb
                  | addv
 
                  | sub
-                 | subb
                  | subv
 
                  | copy
@@ -61,14 +59,16 @@ loopBlockStart = { "[" ~ NEWLINE }
 loopBlockEnd   = { "]" }
 loopBlock      = { loopBlockStart
                  ~ statements
-                 ~ loopBlockEnd
+                 ~ spacing* ~ loopBlockEnd
                  }
 
-statement      =_{ (instruction | loopBlock) }
+statement      =_{ spacing*
+                 ~ (instruction | loopBlock)
+                 }
 
 statements     =_{ (statement | NEWLINE)* }
 
-WHITESPACE     =_{ " "  | "\t" }
+spacing        =_{ " "  | "\t" }
 COMMENT        =_{ ";;" ~ (!NEWLINE ~ ANY)* ~ NEWLINE+ }
 
 file           = { SOI ~ (statement ~ NEWLINE+)* ~ EOI }

src/main.rs

@@ -1,7 +1,10 @@
+#![allow(clippy::from_str_radix_10)]
+use std::cmp::Ordering;
+use std::collections::HashMap;
 use std::fs::File;
 use std::io::Write;
 
-use anyhow::{Context, Result};
+use anyhow::Result;
 use string_builder::Builder;
 use structopt::StructOpt;
 
@@ -16,6 +19,23 @@ use pest::Parser;
 #[grammar = "grammars/mblf.pest"]
 struct MblfParser;
 
+struct MemCell {
+    address: u32,
+}
+
+impl MemCell {
+    pub fn allocate_to(address: u32) -> Self {
+        Self { address }
+    }
+}
+
+struct State {
+    alloc_cnt: u32,
+    free_list: Vec<u32>,
+    mem_pointer: u32,
+    variables: HashMap<String, MemCell>,
+}
+
 #[derive(StructOpt)]
 struct Cli {
     #[structopt(parse(from_os_str))]
@@ -36,137 +56,187 @@ fn extract_operand(statement: Pair<Rule>) -> &str {
     line
 }
 
-fn parse_constant(text: &str) -> Result<i32, std::num::ParseIntError> {
-    if text.starts_with("\"") {
+fn parse_constant(text: &str) -> Result<u32, std::num::ParseIntError> {
+    if text.starts_with('\"') {
         let c = text.chars().nth(1).unwrap();
-        Ok(c as i32)
+        Ok(c as u32)
     } else if text.starts_with("0x") {
         let without_prefix = text.trim_start_matches("0x");
-        i32::from_str_radix(without_prefix, 16)
+        u32::from_str_radix(without_prefix, 16)
     } else {
-        i32::from_str_radix(text, 10)
+        u32::from_str_radix(text, 10)
     }
 }
 
-fn instruct(statement: Pair<Rule>, out: &mut Builder) {
-    match statement.as_rule() {
-        Rule::include => {
-            let file_path = extract_operand(statement);
-            println!("Including {} into this src file", file_path);
-            out.append("#include\n");
-        }
+fn to_bf(rule: Rule, operand: &str, state: &mut State, out: &mut Builder) {
+    match rule {
         Rule::var => {
-            let variable_name = extract_operand(statement);
-            println!("Creation of variable '{}'", variable_name);
-            out.append("var\n");
+            let variable_name = operand;
+
+            let mem_extension: u32;
+            let new_address: u32;
+
+            if !state.free_list.is_empty() {
+                new_address = state.free_list.pop().unwrap();
+                mem_extension = 0;
+            } else {
+                new_address = state.alloc_cnt;
+                mem_extension = 1;
+            }
+
+            if let Some(_v) = state.variables.insert(
+                String::from(variable_name),
+                MemCell::allocate_to(new_address),
+            ) {
+                panic!("Variable '{}' already exists", variable_name);
+            }
+            state.alloc_cnt += mem_extension;
         }
         Rule::delvar => {
-            let variable_name = extract_operand(statement);
-            println!("Deletion of variable '{}'", variable_name);
-            out.append("delvar\n");
+            let variable_name = operand;
+            let memcell = state
+                .variables
+                .get(variable_name)
+                .ok_or_else(|| format!("Variable '{}' did not exists", variable_name))
+                .unwrap();
+            state.free_list.push(memcell.address);
+            state.variables.remove(&String::from(variable_name));
         }
         Rule::point => {
-            let variable_name = extract_operand(statement);
-            println!("Pointing to variable '{}'", variable_name);
-            out.append("point\n");
+            let variable_name = operand;
+            let address = state
+                .variables
+                .get(variable_name)
+                .unwrap_or_else(|| panic!("Variable '{}' did not exists", variable_name))
+                .address
+                .to_string();
+            to_bf(Rule::pointa, &address, state, out)
+        }
+        Rule::pointa => {
+            let address = operand;
+            let address_parsed = parse_constant(address).unwrap();
+            match address_parsed.cmp(&state.mem_pointer) {
+                Ordering::Less => {
+                    out.append("<".repeat((state.mem_pointer - address_parsed) as usize))
+                }
+                Ordering::Greater => {
+                    out.append(">".repeat((address_parsed - state.mem_pointer) as usize))
+                }
+                Ordering::Equal => (),
+            }
+            state.mem_pointer = address_parsed;
         }
         Rule::pointm => {
-            let variable_name = extract_operand(statement);
-            println!("Pointing back to marker variable {}", variable_name);
-            out.append("pointm\n");
+            let variable_name = operand;
+            let address = state
+                .variables
+                .get(variable_name)
+                .unwrap_or_else(|| panic!("Marker variable '{}' did not exists", variable_name))
+                .address;
+            // thank you mixtela
+            out.append("<+[-<+]-");
+            state.mem_pointer = address;
         }
         Rule::add => {
-            let constant = extract_operand(statement);
-            let constant_parsed = parse_constant(constant).unwrap();
-            println!(
-                "Addition of '{}', decimal value is {}",
-                constant, constant_parsed
-            );
-            out.append("add\n");
-        }
-        Rule::addb => {
-            let constant = extract_operand(statement);
+            let constant = operand;
             let constant_parsed = parse_constant(constant).unwrap();
-            println!(
-                "Big Addition of '{}', decimal value is {}",
-                constant, constant_parsed
-            );
-            out.append("addb\n");
+            out.append("+".repeat(constant_parsed as usize));
         }
         Rule::addv => {
-            let variable_name = extract_operand(statement);
-            println!("Addition to variable '{}'", variable_name);
-            out.append("addv\n");
+            let variable_name = operand;
+            let source_address = state.mem_pointer.to_string();
+            out.append("[");
+            to_bf(Rule::sub, "1", state, out);
+            to_bf(Rule::point, variable_name, state, out);
+            to_bf(Rule::add, "1", state, out);
+            to_bf(Rule::pointa, &source_address, state, out);
+            out.append("]");
         }
         Rule::sub => {
-            let constant = extract_operand(statement);
+            let constant = operand;
             let constant_parsed = parse_constant(constant).unwrap();
-            println!(
-                "Subtraction of '{}', decimal value is {}",
-                constant, constant_parsed
-            );
-            out.append("sub\n");
-        }
-        Rule::subb => {
-            let constant = extract_operand(statement);
-            let constant_parsed = parse_constant(constant).unwrap();
-            println!(
-                "Big Subtraction of '{}', decimal value is {}",
-                constant, constant_parsed
-            );
-            out.append("subb\n");
+            out.append("-".repeat(constant_parsed as usize));
         }
         Rule::subv => {
-            let variable_name = extract_operand(statement);
-            println!("Subtraction from variable '{}'", variable_name);
-            out.append("subv\n");
+            let variable_name = operand;
+            let source_address = state.mem_pointer.to_string();
+            out.append("[");
+            to_bf(Rule::sub, "1", state, out);
+            to_bf(Rule::point, variable_name, state, out);
+            to_bf(Rule::sub, "1", state, out);
+            to_bf(Rule::pointa, &source_address, state, out);
+            out.append("]");
         }
         Rule::copy => {
-            let variable_name = extract_operand(statement);
-            println!("Copy to variable '{}'", variable_name);
-            out.append("copy\n");
+            let variable_name = operand;
+            let source_address = state.mem_pointer.to_string();
+            to_bf(Rule::var, "__temp", state, out);
+            out.append("[");
+            to_bf(Rule::sub, "1", state, out);
+            to_bf(Rule::point, variable_name, state, out);
+            to_bf(Rule::add, "1", state, out);
+            to_bf(Rule::point, "__temp", state, out);
+            to_bf(Rule::add, "1", state, out);
+            to_bf(Rule::pointa, &source_address, state, out);
+            out.append("]");
+            to_bf(Rule::point, "__temp", state, out);
+            out.append("[");
+            to_bf(Rule::sub, "1", state, out);
+            to_bf(Rule::pointa, &source_address, state, out);
+            to_bf(Rule::add, "1", state, out);
+            to_bf(Rule::point, "__temp", state, out);
+            out.append("]");
+            to_bf(Rule::delvar, "__temp", state, out);
         }
         Rule::setz => {
-            println!("Set current variable to zero");
-            out.append("setz\n");
+            out.append("[-]");
         }
         Rule::getchr => {
-            println!("Reading char from user input into current variable");
-            out.append("getchr\n");
+            out.append(",");
         }
         Rule::print => {
-            println!("Printing current variable");
-            out.append("print\n");
-        }
-        Rule::instruction => {
-            out.append("\n");
-        }
-        Rule::loopBlock => {
-            for nested_statement in statement.into_inner() {
-                instruct(nested_statement, out);
-            }
+            out.append(".");
         }
         Rule::loopBlockStart => {
-            println!("Start of loopBlock");
-            out.append("loopBlockStart\n");
+            out.append("[");
         }
         Rule::loopBlockEnd => {
-            println!("End of loopBlock");
-            out.append("loopBlockEnd\n");
+            out.append("]");
         }
         Rule::EOI => {
-            println!("End of Input");
             out.append("\n");
         }
         _ => unreachable!(),
     }
 }
 
+fn instruct(statement: Pair<Rule>, state: &mut State, out: &mut Builder) {
+    match statement.as_rule() {
+        Rule::include => {
+            let file_path_raw = extract_operand(statement);
+            let file_path = &file_path_raw[1..file_path_raw.len() - 1];
+            let content = std::fs::read_to_string(&file_path).unwrap();
+            let parsed_file = MblfParser::parse(Rule::file, &content)
+                .expect("Parse Error")
+                .next()
+                .unwrap();
+            for statement in parsed_file.into_inner() {
+                instruct(statement, state, out);
+            }
+        }
+        Rule::loopBlock => {
+            for nested_statement in statement.into_inner() {
+                instruct(nested_statement, state, out);
+            }
+        }
+        _ => to_bf(statement.as_rule(), extract_operand(statement), state, out),
+    }
+}
+
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let args = Cli::from_args();
 
-    let content = std::fs::read_to_string(&args.input_file)
-        .with_context(|| format!("could not read source file {:?}", args.input_file))?;
+    let content = std::fs::read_to_string(&args.input_file)?;
 
     let mut builder = Builder::default();
 
@@ -175,15 +245,71 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         .next()
         .unwrap();
 
-    for statement in parsed_file.into_inner() {
-        instruct(statement, &mut builder);
+    let mut state = State {
+        alloc_cnt: 0,
+        free_list: Vec::new(),
+        mem_pointer: 0,
+        variables: HashMap::new(),
+    };
+    for stmt in parsed_file.into_inner() {
+        instruct(stmt, &mut state, &mut builder);
     }
 
     let bf = builder.string().unwrap();
 
     let mut out = File::create(args.output_file)?;
-    out.write(bf.as_bytes())?;
+    out.write_all(bf.as_bytes())?;
     out.sync_all()?;
 
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_constant() {
+        assert_eq!(parse_constant(&"42"), Ok(42));
+        assert_eq!(parse_constant(&"0x2A"), Ok(42));
+        assert_eq!(parse_constant(&"\"*\""), Ok(42));
+
+        assert!(
+            matches!(
+                parse_constant(&"\'*\'"),
+                Err(std::num::ParseIntError { .. })
+            ),
+            "Char literals are declared with \"_\", not \'_\'"
+        );
+    }
+
+    #[test]
+    fn test_reuse_of_free_memcells() {
+        let mut builder = Builder::default();
+        let mut state = State {
+            alloc_cnt: 0,
+            free_list: Vec::new(),
+            mem_pointer: 0,
+            variables: HashMap::new(),
+        };
+
+        to_bf(Rule::var, "abc", &mut state, &mut builder);
+        assert_eq!(state.alloc_cnt, 1);
+
+        to_bf(Rule::delvar, "abc", &mut state, &mut builder);
+        assert_eq!(
+            state.alloc_cnt, 1,
+            "allocation should not be shrunken, that is too costly"
+        );
+
+        to_bf(Rule::var, "def", &mut state, &mut builder);
+        assert_ne!(
+            state.alloc_cnt, 2,
+            "the just de-allocated memorycell should be re-used"
+        );
+        assert_eq!(
+            state.alloc_cnt, 1,
+            "alloc, dealloc, alloc has a max usage of one memorycell"
+        );
+    }
+}