diff --git a/.gitignore b/.gitignore
index 08b7716..ba13579 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
/target
osmarkscalculator.zip
osmarkscalculator.tar
-src.zip
\ No newline at end of file
+src.zip
+dist
+vgcore*
\ No newline at end of file
diff --git a/Cargo.lock b/Cargo.lock
index c2f2556..ad1ea11 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9,10 +9,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "61604a8f862e1d5c3229fdd78f8b02c68dcf73a4c4b05fd636d12240aaa242c1"
[[package]]
-name = "autocfg"
-version = "1.0.1"
+name = "bumpalo"
+version = "3.11.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
+checksum = "572f695136211188308f16ad2ca5c851a712c464060ae6974944458eb83880ba"
+
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
[[package]]
name = "cfg-if"
@@ -20,65 +26,12 @@ version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
-[[package]]
-name = "crossbeam-channel"
-version = "0.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e54ea8bc3fb1ee042f5aace6e3c6e025d3874866da222930f70ce62aceba0bfa"
-dependencies = [
- "cfg-if",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-deque"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6455c0ca19f0d2fbf751b908d5c55c1f5cbc65e03c4225427254b46890bdde1e"
-dependencies = [
- "cfg-if",
- "crossbeam-epoch",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-epoch"
-version = "0.9.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97242a70df9b89a65d0b6df3c4bf5b9ce03c5b7309019777fbde37e7537f8762"
-dependencies = [
- "cfg-if",
- "crossbeam-utils",
- "lazy_static",
- "memoffset",
- "scopeguard",
-]
-
-[[package]]
-name = "crossbeam-utils"
-version = "0.8.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfcae03edb34f947e64acdb1c33ec169824e20657e9ecb61cef6c8c74dcb8120"
-dependencies = [
- "cfg-if",
- "lazy_static",
-]
-
[[package]]
name = "either"
version = "1.6.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
-[[package]]
-name = "hermit-abi"
-version = "0.1.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
-dependencies = [
- "libc",
-]
-
[[package]]
name = "inlinable_string"
version = "0.1.14"
@@ -94,36 +47,32 @@ dependencies = [
"either",
]
-[[package]]
-name = "lazy_static"
-version = "1.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
-
[[package]]
name = "libc"
-version = "0.2.114"
+version = "0.2.137"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0005d08a8f7b65fb8073cb697aa0b12b631ed251ce73d862ce50eeb52ce3b50"
+checksum = "fc7fcc620a3bff7cdd7a365be3376c97191aeaccc2a603e600951e452615bf89"
[[package]]
-name = "memoffset"
-version = "0.6.5"
+name = "log"
+version = "0.4.17"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5aa361d4faea93603064a027415f07bd8e1d5c88c9fbf68bf56a285428fd79ce"
+checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
dependencies = [
- "autocfg",
+ "cfg-if 1.0.0",
]
[[package]]
-name = "num_cpus"
-version = "1.13.1"
+name = "memory_units"
+version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "19e64526ebdee182341572e50e9ad03965aa510cd94427a4549448f285e957a1"
-dependencies = [
- "hermit-abi",
- "libc",
-]
+checksum = "8452105ba047068f40ff7093dd1d9da90898e63dd61736462e9cdda6a90ad3c3"
+
+[[package]]
+name = "once_cell"
+version = "1.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86f0b0d4bf799edbc74508c1e8bf170ff5f41238e5f8225603ca7caaae2b7860"
[[package]]
name = "osmarkscalculator"
@@ -132,36 +81,129 @@ dependencies = [
"anyhow",
"inlinable_string",
"itertools",
- "rayon",
+ "wasm-bindgen",
+ "wee_alloc",
]
[[package]]
-name = "rayon"
-version = "1.5.1"
+name = "proc-macro2"
+version = "1.0.47"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c06aca804d41dbc8ba42dfd964f0d01334eceb64314b9ecf7c5fad5188a06d90"
+checksum = "5ea3d908b0e36316caf9e9e2c4625cdde190a7e6f440d794667ed17a1855e725"
dependencies = [
- "autocfg",
- "crossbeam-deque",
- "either",
- "rayon-core",
+ "unicode-ident",
]
[[package]]
-name = "rayon-core"
-version = "1.9.1"
+name = "quote"
+version = "1.0.21"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d78120e2c850279833f1dd3582f730c4ab53ed95aeaaaa862a2a5c71b1656d8e"
+checksum = "bbe448f377a7d6961e30f5955f9b8d106c3f5e449d493ee1b125c1d43c2b5179"
dependencies = [
- "crossbeam-channel",
- "crossbeam-deque",
- "crossbeam-utils",
- "lazy_static",
- "num_cpus",
+ "proc-macro2",
]
[[package]]
-name = "scopeguard"
-version = "1.1.0"
+name = "syn"
+version = "1.0.103"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
+checksum = "a864042229133ada95abf3b54fdc62ef5ccabe9515b64717bcb9a1919e59445d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ceab39d59e4c9499d4e5a8ee0e2735b891bb7308ac83dfb4e80cad195c9f6f3"
+
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eaf9f5aceeec8be17c128b2e93e031fb8a4d469bb9c4ae2d7dc1888b26887268"
+dependencies = [
+ "cfg-if 1.0.0",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c8ffb332579b0557b52d268b91feab8df3615f265d5270fec2a8c95b17c1142"
+dependencies = [
+ "bumpalo",
+ "log",
+ "once_cell",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "052be0f94026e6cbc75cdefc9bae13fd6052cdcaf532fa6c45e7ae33a1e6c810"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "07bc0c051dc5f23e307b13285f9d75df86bfdf816c5721e573dec1f9b8aa193c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1c38c045535d93ec4f0b4defec448e4291638ee608530863b1e2ba115d4fff7f"
+
+[[package]]
+name = "wee_alloc"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbb3b5a6b2bb17cb6ad44a2e68a43e8d2722c997da10e928665c72ec6c0a0b8e"
+dependencies = [
+ "cfg-if 0.1.10",
+ "libc",
+ "memory_units",
+ "winapi",
+]
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
diff --git a/Cargo.toml b/Cargo.toml
index dc28a8d..a2a9cae 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,10 +3,23 @@ name = "osmarkscalculator"
version = "0.1.0"
edition = "2018"
+[lib]
+crate-type = ["cdylib", "rlib"]
+name = "osmarkscalculator"
+
+[[bin]]
+name = "osmarkscalculator"
+path = "src/main.rs"
+
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
anyhow = "1"
inlinable_string = "0.1"
-rayon = "1.5"
-itertools = "0.10"
\ No newline at end of file
+itertools = "0.10"
+wasm-bindgen = "0.2.63"
+wee_alloc = "0.4.5"
+
+[profile.release]
+opt-level = "s"
+lto = true
\ No newline at end of file
diff --git a/buildcalc.py b/buildcalc.py
new file mode 100644
index 0000000..8c1c4f5
--- /dev/null
+++ b/buildcalc.py
@@ -0,0 +1,44 @@
+BINDING = """
+let loaded = false
+onmessage = async ev => {
+ if (!loaded) {
+ await wasm_bindgen("./osmarkscalculator.wasm")
+ loaded = true
+ }
+ var [fn, ...args] = ev.data
+ let init = false
+ if (fn === "deinit") {
+ wasm_bindgen.deinit_context()
+ init = false
+ } else if (fn === "run") {
+ const start = performance.now()
+ try {
+ if (!init) {
+ wasm_bindgen.init_context()
+ wasm_bindgen.load_defaults()
+ init = true;
+ }
+ postMessage(["ok", wasm_bindgen.run_program(args[0]), performance.now() - start])
+ } catch(e) {
+ postMessage(["error", e.toString(), performance.now() - start])
+ }
+ }
+}
+"""
+HEADER = """
+---
+title: osmarkscalculator
+description: Unholy horrors moved from the depths of my projects directory to your browser. Theoretically, this is a calculator. Good luck using it.
+---
+""".strip()
+import subprocess, rjsmin, os, shutil
+subprocess.run(["wasm-pack", "build", "--target=no-modules"])
+minified = rjsmin.jsmin(open("pkg/osmarkscalculator.js", "r").read() + BINDING)
+os.makedirs("dist", exist_ok=True)
+subprocess.run(["wasm-opt", "-Oz", "pkg/osmarkscalculator_bg.wasm", "-o", "dist/osmarkscalculator.wasm"])
+open("dist/osmarkscalculator.js", "w").write(minified)
+with open("index.html") as f:
+ g = HEADER + f.read().replace("""""", "")
+with open("dist/index.html", "w") as h:
+ h.write(g)
+shutil.copytree("dist/.", "../website/experiments/osmarkscalculator", dirs_exist_ok=True)
\ No newline at end of file
diff --git a/index.html b/index.html
new file mode 100644
index 0000000..5f8d8ee
--- /dev/null
+++ b/index.html
@@ -0,0 +1,72 @@
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..6dfbc2a
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,658 @@
+use anyhow::{Result, Context, bail};
+use inlinable_string::InlinableString;
+use std::collections::HashMap;
+use std::borrow::Cow;
+use std::convert::TryInto;
+use std::sync::Arc;
+use wasm_bindgen::prelude::*;
+
+#[global_allocator]
+static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+
+mod parse;
+mod value;
+mod util;
+mod env;
+
+use value::Value;
+use env::{Rule, Ruleset, Env, Bindings, RuleResult, Operation};
+
+// Main pattern matcher function;
+fn match_and_bind(expr: &Value, rule: &Rule, env: &Env) -> Result> {
+ fn go(expr: &Value, cond: &Value, env: &Env, already_bound: &Bindings) -> Result> {
+ match (expr, cond) {
+ // numbers match themselves
+ (Value::Num(a), Value::Num(b)) => if a == b { Ok(Some(HashMap::new())) } else { Ok(None) },
+ // handle predicated value - check all predicates, succeed with binding if they match
+ (val, Value::Call(x, args)) if x == "#" => {
+ let preds = &args[1..];
+ let (mut success, mut bindings) = match go(val, &args[0], env, already_bound)? {
+ Some(bindings) => (true, bindings),
+ None => (false, already_bound.clone())
+ };
+
+ for pred in preds {
+ match pred {
+ // "Num" predicate matches successfully if something is a number
+ Value::Identifier(i) if i.as_ref() == "Num" => {
+ match val {
+ Value::Num(_) => (),
+ _ => success = false
+ }
+ },
+ // "Ident" does the same for idents
+ Value::Identifier(i) if i.as_ref() == "Ident" => {
+ match val {
+ Value::Identifier(_) => (),
+ _ => success = false
+ }
+ },
+ // Invert match success
+ Value::Identifier(i) if i.as_ref() == "Not" => {
+ success = !success
+ },
+ Value::Call(head, args) if head.as_ref() == "And" => {
+ // Try all patterns it's given, and if any fails then fail the match
+ for arg in args.iter() {
+ match go(val, arg, env, &bindings)? {
+ Some(new_bindings) => bindings.extend(new_bindings),
+ None => success = false
+ }
+ }
+ },
+ Value::Call(head, args) if head.as_ref() == "Eq" => {
+ // Evaluate all arguments and check if they are equal
+ let mut compare_against = None;
+ for arg in args.iter() {
+ let mut evaluated_value = arg.subst(&bindings);
+ run_rewrite(&mut evaluated_value, env).context("evaluating Eq predicate")?;
+ match compare_against {
+ Some(ref x) => if x != &evaluated_value {
+ success = false
+ },
+ None => compare_against = Some(evaluated_value)
+ }
+ }
+ },
+ Value::Call(head, args) if head.as_ref() == "Gte" => {
+ // Evaluate all arguments and do comparison.
+ let mut x = args[0].subst(&bindings);
+ let mut y = args[1].subst(&bindings);
+ run_rewrite(&mut x, env).context("evaluating Gte predicate")?;
+ run_rewrite(&mut y, env).context("evaluating Gte predicate")?;
+ success &= x >= y;
+ },
+ Value::Call(head, args) if head.as_ref() == "Or" => {
+ // Tries all patterns it's given and will set the match to successful if *any* of them works
+ for arg in args.iter() {
+ match go(val, arg, env, &bindings)? {
+ Some(new_bindings) => {
+ bindings.extend(new_bindings);
+ success = true
+ },
+ None => ()
+ }
+ }
+ },
+ _ => bail!("invalid predicate {:?}", pred)
+ }
+ }
+ Ok(match success {
+ true => Some(bindings),
+ false => None
+ })
+ },
+ (Value::Call(exp_head, exp_args), Value::Call(rule_head, rule_args)) => {
+ let mut exp_args = Cow::Borrowed(exp_args);
+ // Regardless of any special casing for associativity etc., different heads mean rules can never match
+ if exp_head != rule_head { return Ok(None) }
+
+ let op = env.get_op(exp_head);
+
+ // Copy bindings from the upper-level matching, so that things like "a+(b+a)" work.
+ let mut out_bindings = already_bound.clone();
+
+ // Special case for associative expressions: split off extra arguments into a new tree
+ if op.associative && rule_args.len() < exp_args.len() {
+ let exp_args = exp_args.to_mut();
+ let rest = exp_args.split_off(rule_args.len() - 1);
+ let rem = Value::Call(exp_head.clone(), rest);
+ exp_args.push(rem);
+ }
+ if rule_args.len() != exp_args.len() { return Ok(None) }
+
+ // Try and match all "adjacent" arguments to each other
+ for (rule_arg, exp_arg) in rule_args.iter().zip(&*exp_args) {
+ match go(exp_arg, rule_arg, env, &out_bindings)? {
+ Some(x) => out_bindings.extend(x),
+ None => return Ok(None)
+ }
+ }
+ Ok(Some(out_bindings))
+ },
+ // identifier pattern matches anything, unless the identifier has already been bound to something else
+ (x, Value::Identifier(a)) => {
+ if let Some(b) = already_bound.get(a) {
+ if b != x {
+ return Ok(None);
+ }
+ };
+ Ok(Some(vec![(a.clone(), x.clone())].into_iter().collect()))
+ },
+ // anything else doesn't match
+ _ => Ok(None)
+ }
+ }
+ // special case at top level of expression - try to match pattern to different subranges of input
+ match (expr, &rule.condition) {
+ // this only applies to matching one "call" against a "call" pattern (with same head)
+ (Value::Call(ehead, eargs), Value::Call(rhead, rargs)) => {
+ // and also only to associative operations
+ if env.get_op(ehead).associative && eargs.len() > rargs.len() && ehead == rhead {
+ // consider all possible subranges of the arguments of the appropriate length
+ for range_start in 0..=(eargs.len() - rargs.len()) {
+ // extract the arguments & convert into new Value
+ let c_args = eargs[range_start..range_start + rargs.len()].iter().cloned().collect();
+ let c_call = Value::Call(ehead.clone(), c_args);
+ // attempt to match the new subrange against the current rule
+ if let Some(r) = match_and_bind(&c_call, rule, env)? {
+ // generate new output with result
+ let mut new_args = Vec::with_capacity(3);
+ // add back extra start items
+ if range_start != 0 {
+ new_args.push(Value::Call(ehead.clone(), eargs[0..range_start].iter().cloned().collect()))
+ }
+ new_args.push(r);
+ // add back extra end items
+ if range_start + rargs.len() != eargs.len() {
+ new_args.push(Value::Call(ehead.clone(), eargs[range_start + rargs.len()..eargs.len()].iter().cloned().collect()))
+ }
+ let new_exp = Value::Call(ehead.clone(), new_args);
+ return Ok(Some(new_exp))
+ }
+ }
+ }
+ }
+ _ => ()
+ }
+ // substitute bindings from matching into either an intrinsic or the output of the rule
+ if let Some(bindings) = go(expr, &rule.condition, env, &HashMap::new())? {
+ Ok(Some(match &rule.result {
+ RuleResult::Intrinsic(id) => env.intrinsics.get(id).unwrap()(&bindings).with_context(|| format!("applying intrinsic {}", id))?,
+ RuleResult::Exp(e) => e.subst(&bindings)
+ }))
+ } else {
+ Ok(None)
+ }
+}
+
+// Sort any commutative expressions
+fn canonical_sort(v: &mut Value, env: &Env) -> Result<()> {
+ match v {
+ Value::Call(head, args) => if env.get_op(head).commutative {
+ args.sort();
+ },
+ _ => ()
+ }
+ Ok(())
+}
+
+// Associative expression flattening.
+fn flatten_tree(v: &mut Value, env: &Env) -> Result<()> {
+ match v {
+ Value::Call(head, args) => {
+ if env.get_op(head).associative {
+ // Not the most efficient algorithm, but does work.
+ // Repeatedly find the position of a flatten-able child node, and splice it into the argument list.
+ loop {
+ let mut move_pos = None;
+ for (i, child) in args.iter().enumerate() {
+ if let Some(child_head) = child.head() {
+ if *head == child_head {
+ move_pos = Some(i)
+ }
+ }
+ }
+ match move_pos {
+ Some(pos) => {
+ let removed = std::mem::replace(&mut args[pos], Value::Num(0));
+ // We know that removed will be a Call (because its head wasn't None earlier). Unfortunately, rustc does not know this.
+ match removed {
+ Value::Call(_, removed_child_args) => args.splice(pos..=pos, removed_child_args.into_iter()),
+ _ => unreachable!()
+ };
+ },
+ None => break
+ }
+ }
+ }
+ // Also do sorting after flattening, to avoid any weirdness with ordering.
+ canonical_sort(v, env)?;
+ return Ok(())
+ },
+ _ => return Ok(())
+ }
+}
+
+// Applies rewrite rulesets to an expression.
+fn run_rewrite(v: &mut Value, env: &Env) -> Result<()> {
+ loop {
+ // Compare original and final hash instead of storing a copy of the original value and checking equality
+ // Collision probability is negligible and this is substantially faster than storing/comparing copies.
+ let original_hash = v.get_hash();
+
+ flatten_tree(v, env).context("flattening tree")?;
+ // Call expressions can be rewritten using pattern matching rules; identifiers can be substituted for bindings if available
+ match v {
+ Value::Call(head, args) => {
+ let head = head.clone();
+
+ // Rewrite sub-expressions using existing environment
+ args.iter_mut().try_for_each(|arg| run_rewrite(arg, env).with_context(|| format!("rewriting {}", arg.render_to_string(env))))?;
+
+ // Try to apply all applicable rules from all rulesets, in sequence
+ for ruleset in env.ruleset.iter() {
+ if let Some(rules) = ruleset.get(&head) {
+ // Within a ruleset, rules are applied backward. This is nicer for users using the program interactively.
+ for rule in rules.iter().rev() {
+ if let Some(result) = match_and_bind(v, rule, env).with_context(|| format!("applying rule {} -> {:?}", rule.condition.render_to_string(env), rule.result))? {
+ *v = result;
+ flatten_tree(v, env).context("flattening tree after rule application")?;
+ }
+ }
+ }
+ }
+ },
+ // Substitute in bindings which have been provided
+ Value::Identifier(ident) => {
+ match env.bindings.get(ident) {
+ Some(val) => {
+ *v = val.clone();
+ },
+ None => return Ok(())
+ }
+ },
+ _ => {
+ return Ok(())
+ }
+ }
+ if original_hash == v.get_hash() {
+ break
+ }
+ }
+ Ok(())
+}
+
+// Utility function for defining intrinsic functions for binary operators.
+// Converts a function which does the actual operation to a function from bindings to a value.
+fn wrap_binop Result + Sync + Send>(op: F) -> Box Result + Sync + Send> {
+ Box::new(move |bindings: &Bindings| {
+ let a = bindings.get(&InlinableString::from("a")).context("binop missing first argument")?.assert_num("binop first argument")?;
+ let b = bindings.get(&InlinableString::from("b")).context("binop missing second argument")?.assert_num("binop second argument")?;
+ op(a, b).map(Value::Num)
+ })
+}
+
+// Provides a basic environment with operator commutativity/associativity operations and intrinsics.
+fn make_initial_env() -> Env {
+ let mut ops = HashMap::new();
+ ops.insert(InlinableString::from("+"), Operation { commutative: true, associative: true });
+ ops.insert(InlinableString::from("*"), Operation { commutative: true, associative: true });
+ ops.insert(InlinableString::from("-"), Operation { commutative: false, associative: false });
+ ops.insert(InlinableString::from("/"), Operation { commutative: false, associative: false });
+ ops.insert(InlinableString::from("^"), Operation { commutative: false, associative: false });
+ ops.insert(InlinableString::from("="), Operation { commutative: false, associative: false });
+ ops.insert(InlinableString::from("#"), Operation { commutative: false, associative: true });
+ let ops = Arc::new(ops);
+ let mut intrinsics = HashMap::new();
+ intrinsics.insert(0, wrap_binop(|a, b| a.checked_add(b).context("integer overflow")));
+ intrinsics.insert(1, wrap_binop(|a, b| a.checked_sub(b).context("integer overflow")));
+ intrinsics.insert(2, wrap_binop(|a, b| a.checked_mul(b).context("integer overflow")));
+ intrinsics.insert(3, wrap_binop(|a, b| a.checked_div(b).context("division by zero")));
+ intrinsics.insert(4, wrap_binop(|a, b| {
+ // The "pow" function takes a usize (machine-sized unsigned integer) and an i128 may not fit into this, so an extra conversion is needed
+ Ok(a.pow(b.try_into()?))
+ }));
+ intrinsics.insert(5, Box::new(|bindings| {
+ // Substitute a single, given binding var=value into a target expression
+ let var = bindings.get(&InlinableString::from("var")).unwrap();
+ let value = bindings.get(&InlinableString::from("value")).unwrap();
+ let target = bindings.get(&InlinableString::from("target")).unwrap();
+ let name = var.assert_ident("Subst")?;
+ let mut new_bindings = HashMap::new();
+ new_bindings.insert(name, value.clone());
+ Ok(target.subst(&new_bindings))
+ }));
+ intrinsics.insert(6, wrap_binop(|a, b| a.checked_rem(b).context("division by zero")));
+ let intrinsics = Arc::new(intrinsics);
+ Env {
+ ruleset: vec![],
+ ops: ops.clone(),
+ intrinsics: intrinsics.clone(),
+ bindings: HashMap::new()
+ }
+}
+
+pub const BUILTINS: &str = "
+SetStage[all]
+a#Num + b#Num = Intrinsic[0]
+a#Num - b#Num = Intrinsic[1]
+a#Num * b#Num = Intrinsic[2]
+a#Num / b#Num = Intrinsic[3]
+a#Num ^ b#Num = Intrinsic[4]
+Subst[var=value, target] = Intrinsic[5]
+Mod[a#Num, b#Num] = Intrinsic[6]
+PushRuleset[builtins]
+";
+
+pub const GENERAL_RULES: &str = "
+SetStage[all]
+(a*b#Num)+(a*c#Num) = (b+c)*a
+Negate[a] = 0 - a
+a^b*a^c = a^(b+c)
+a^0 = 1
+a^1 = a
+(a^b)^c = a^(b*c)
+0*a = 0
+0+a = a
+1*a = a
+x/x = 1
+(n*x)/x = n
+PushRuleset[general_rules]
+";
+
+pub const NORMALIZATION_RULES: &str = "
+SetStage[norm]
+a/b = a*b^Negate[1]
+a+b#Num*a = (b+1)*a
+a^b#Num#Gte[b, 2] = a*a^(b-1)
+a-c#Num*b = a+Negate[c]*b
+a+a = 2*a
+a*(b+c) = a*b+a*c
+a-b = a+Negate[1]*b
+PushRuleset[normalization]
+";
+
+pub const DENORMALIZATION_RULES: &str = "
+SetStage[denorm]
+a*a = a^2
+a^b#Num*a = a^(b+1)
+c+a*b#Num#Gte[0, b] = c-a*Negate[b]
+PushRuleset[denormalization]
+";
+
+pub const DIFFERENTIATION_DEFINITION: &str = "
+SetStage[all]
+D[x, x] = 1
+D[a#Num, x] = 0
+D[f+g, x] = D[f, x] + D[g, x]
+D[f*g, x] = D[f, x] * g + D[g, x] * f
+D[a#Num*f, x] = a * D[f, x]
+PushRuleset[differentiation]
+";
+
+pub const FACTOR_DEFINITION: &str = "
+SetStage[post_norm]
+Factor[x, a*x+b] = x * (a + Factor[x, b] / x)
+PushRuleset[factor]
+SetStage[pre_denorm]
+Factor[x, a] = a
+PushRuleset[factor_postprocess]
+SetStage[denorm]
+x^n/x = x^(n-1)
+(a*x^n)/x = a*x^(n-1)
+PushRuleset[factor_postpostprocess]
+";
+
+
+pub struct ImperativeCtx {
+ bindings: Bindings,
+ current_ruleset_stage: InlinableString,
+ current_ruleset: Ruleset,
+ rulesets: HashMap>,
+ stages: Vec<(InlinableString, Vec)>,
+ pub base_env: Env
+}
+
+impl ImperativeCtx {
+ // Make a new imperative context
+ // Stages are currently hardcoded, as adding a way to manage them would add lots of complexity
+ // for limited benefit
+ pub fn init() -> Self {
+ let stages = [
+ "pre_norm",
+ "norm",
+ "post_norm",
+ "pre_denorm",
+ "denorm",
+ "post_denorm"
+ ].iter().map(|name| (InlinableString::from(*name), vec![])).collect();
+ ImperativeCtx {
+ bindings: HashMap::new(),
+ current_ruleset_stage: InlinableString::from("post_norm"),
+ current_ruleset: HashMap::new(),
+ rulesets: HashMap::new(),
+ stages,
+ base_env: make_initial_env()
+ }
+ }
+
+ // Insert a rule into the current ruleset; handles switching out the result for a relevant intrinsic use, generating possible reorderings, and inserting into the lookup map.
+ fn insert_rule(&mut self, condition: &Value, result_val: Value) -> Result<()> {
+ let result = match result_val {
+ Value::Call(head, args) if head == "Intrinsic" => RuleResult::Intrinsic(args[0].assert_num("Intrinsic ID")? as usize),
+ _ => RuleResult::Exp(result_val)
+ };
+ for rearrangement in condition.pattern_reorderings(&self.base_env).into_iter() {
+ let rule = Rule {
+ condition: rearrangement,
+ result: result.clone()
+ };
+ self.current_ruleset.entry(condition.head().unwrap()).or_insert_with(Vec::new).push(rule);
+ }
+ Ok(())
+ }
+
+ // Run a single statement (roughly, a line of user input) on the current context
+ fn eval_statement(&mut self, mut stmt: Value) -> Result> {
+ match stmt {
+ // = sets a binding or generates a new rule.
+ Value::Call(head, args) if head.as_ref() == "=" => {
+ match &args[0] {
+ // Create a binding if the LHS (left hand side) is just an identifier
+ Value::Identifier(id) => {
+ let rhs = self.eval_statement(args[1].clone())?;
+ if let Some(val) = rhs.clone() {
+ self.bindings.insert(id.clone(), val);
+ }
+ Ok(rhs)
+ },
+ // If the LHS is a call, then a rule should be created instead.
+ Value::Call(_head, _args) => {
+ let rhs = self.eval_statement(args[1].clone())?;
+ if let Some(val) = rhs.clone() {
+ self.insert_rule(&args[0], val)?;
+ }
+ Ok(rhs)
+ },
+ // Rebinding numbers can only bring confusion, so it is not allowed.
+ // They also do not have a head, and so cannot be inserted into the ruleset anyway.
+ Value::Num(_) => bail!("You cannot rebind numbers")
+ }
+ },
+ // SetStage[] calls set the stage the current ruleset will be applied at
+ Value::Call(head, args) if head.as_ref() == "SetStage" => {
+ let stage = args[0].assert_ident("SetStage requires an identifier for stage")?;
+ if stage != "all" && None == self.stages.iter().position(|s| s.0 == stage) {
+ bail!("No such stage {}", stage);
+ }
+ self.current_ruleset_stage = stage;
+ Ok(None)
+ },
+ // Move the current ruleset from the "buffer" into the actual list of rules to be applied at each stage
+ Value::Call(head, args) if head.as_ref() == "PushRuleset" => {
+ let name = args[0].assert_ident("PushRuleset requires an identifier for ruleset name")?;
+ // Get ruleset and set the current one to empty
+ let ruleset = std::mem::replace(&mut self.current_ruleset, HashMap::new());
+ // Push ruleset to stages it specifies
+ for (stage_name, stage_rulesets) in self.stages.iter_mut() {
+ if *stage_name == self.current_ruleset_stage || self.current_ruleset_stage == "all" {
+ stage_rulesets.push(name.clone());
+ }
+ }
+ // Insert actual ruleset data under its name
+ self.rulesets.insert(name, Arc::new(ruleset));
+ Ok(None)
+ },
+ // Anything not special should just be repeatedly run through each rewrite stage.
+ _ => {
+ let env = self.base_env.with_bindings(&self.bindings);
+ for (stage_name, stage_rulesets) in self.stages.iter() {
+ // Add relevant rulesets to a new environment for this stage
+ let mut env = env.clone();
+ for ruleset in stage_rulesets.iter() {
+ env = env.with_ruleset(self.rulesets[ruleset].clone());
+ }
+ // Also add the current ruleset if applicable
+ if self.current_ruleset_stage == *stage_name || self.current_ruleset_stage == "all" {
+ env = env.with_ruleset(Arc::new(self.current_ruleset.clone()));
+ }
+ run_rewrite(&mut stmt, &env).with_context(|| format!("failed in {} stage", stage_name))?;
+ // If a ruleset is only meant to be applied in one particular stage, it shouldn't have any later stages applied to it,
+ // or the transformation it's meant to do may be undone
+ if self.current_ruleset_stage == *stage_name {
+ break
+ }
+ }
+ Ok(Some(stmt))
+ }
+ }
+ }
+
+ // Evaluate an entire "program" (multiple statements delineated by ; or newlines)
+ pub fn eval_program(&mut self, program: &str) -> Result> {
+ let mut tokens = parse::lex(program)?;
+ let mut last_value = None;
+ loop {
+ // Split at the next break token
+ let remaining_tokens = tokens.iter().position(|x| *x == parse::Token::Break).map(|ix| tokens.split_off(ix + 1));
+ // Trim EOF/break tokens
+ match tokens[tokens.len() - 1] {
+ parse::Token::Break | parse::Token::EOF => tokens.truncate(tokens.len() - 1),
+ _ => ()
+ };
+ // If the statement/line isn't blank, readd EOF for the parser, parse into an AST then Value, and evaluate the statement
+ if tokens.len() > 0 {
+ tokens.push(parse::Token::EOF);
+ let value = Value::from_ast(parse::parse(tokens)?);
+ last_value = self.eval_statement(value)?;
+ }
+ // If there was no break after the current position, this is now done. Otherwise, move onto the new remaining tokens.
+ match remaining_tokens {
+ Some(t) => { tokens = t },
+ None => break
+ }
+ }
+ Ok(last_value)
+ }
+}
+
+static mut JS_CONTEXT: Option = None;
+
+#[wasm_bindgen]
+pub fn init_context() {
+ unsafe {
+ JS_CONTEXT = Some(ImperativeCtx::init());
+ }
+}
+unsafe fn load_defaults_internal() -> Result<()> {
+ let ctx = (&mut JS_CONTEXT).as_mut().unwrap();
+ ctx.eval_program(BUILTINS)?;
+ ctx.eval_program(GENERAL_RULES)?;
+ ctx.eval_program(FACTOR_DEFINITION)?;
+ ctx.eval_program(DENORMALIZATION_RULES)?;
+ ctx.eval_program(NORMALIZATION_RULES)?;
+ ctx.eval_program(DIFFERENTIATION_DEFINITION)?;
+ Ok(())
+}
+#[wasm_bindgen]
+pub fn load_defaults() {
+ unsafe {
+ load_defaults_internal().unwrap();
+ }
+}
+#[wasm_bindgen]
+pub fn run_program(program: &str) -> String {
+ unsafe {
+ let ctx = (&mut JS_CONTEXT).as_mut().unwrap();
+ match ctx.eval_program(program) {
+ Ok(Some(result)) => result.render_to_string(&ctx.base_env).to_string(),
+ Ok(None) => String::new(),
+ Err(e) => format!("Error: {:?}", e)
+ }
+ }
+}
+#[wasm_bindgen]
+pub fn deinit_context() {
+ unsafe {
+ std::mem::take(&mut JS_CONTEXT);
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use crate::{ImperativeCtx, BUILTINS, GENERAL_RULES, NORMALIZATION_RULES, DENORMALIZATION_RULES, DIFFERENTIATION_DEFINITION, FACTOR_DEFINITION};
+
+ #[test]
+ fn end_to_end_tests() {
+ let mut ctx = ImperativeCtx::init();
+ ctx.eval_program(BUILTINS).unwrap();
+ ctx.eval_program(GENERAL_RULES).unwrap();
+ ctx.eval_program(FACTOR_DEFINITION).unwrap();
+ ctx.eval_program(DENORMALIZATION_RULES).unwrap();
+ ctx.eval_program(NORMALIZATION_RULES).unwrap();
+ ctx.eval_program(DIFFERENTIATION_DEFINITION).unwrap();
+ let test_cases = [
+ ("Factor[x, x*3+x^2]", "(3+x)*x"),
+ ("x^a/x^(a+1)", "x^Negate[1]"),
+ ("Negate[a+b]", "Negate[1]*b-a"),
+ ("Subst[x=4, x+4+4+4+4]", "20"),
+ ("(a+b)*(c+d)*(e+f)", "a*c*e+a*c*f+a*d*e+a*d*f+b*c*e+b*c*f+b*d*e+b*d*f"),
+ ("(12+55)^3-75+16/(2*2)+5+3*4", "300709"),
+ ("D[3*x^3 + 6*x, x] ", "6+9*x^2"),
+ ("Fib[n] = Fib[n-1] + Fib[n-2]
+ Fib[0] = 0
+ Fib[1] = 1
+ Fib[6]", "8"),
+ ("Subst[b=a, b+a]", "2*a"),
+ ("a = 7
+ b = Negate[4]
+ a + b", "3"),
+ ("IsEven[x] = 0
+ IsEven[x#Eq[Mod[x, 2], 0]] = 1
+ IsEven[3] - IsEven[4]", "Negate[1]"),
+ ("(a+b+c)^2", "2*a*b+2*a*c+2*b*c+a^2+b^2+c^2"),
+ ("(x+2)^7", "128+2*x^6+12*x^5+12*x^6+16*x^3+16*x^5+24*x^4+24*x^5+32*x^2+32*x^3+32*x^5+128*x^2+256*x^4+448*x+512*x^2+512*x^3+x^7")
+ ];
+ for (input, expected_result) in test_cases {
+ let lhs = ctx.eval_program(input).unwrap();
+ let lhs = lhs.as_ref().unwrap().render_to_string(&ctx.base_env);
+ println!("{} evaluated to {}; expected {}", input, lhs, expected_result);
+ assert_eq!(lhs, expected_result);
+ }
+
+ let error_cases = [
+ ("1/0")
+ ];
+
+ for error_case in error_cases {
+ if let Err(e) = ctx.eval_program(error_case) {
+ println!("{} produced error {:?}", error_case, e);
+ } else {
+ panic!("should have errored: {}", error_case)
+ }
+ }
+
+ println!("All tests passed.")
+ }
+}
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 82a9e55..1373dd6 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,558 +1,6 @@
-use anyhow::{Result, Context, bail};
-use inlinable_string::InlinableString;
-use std::collections::HashMap;
+use osmarkscalculator::*;
use std::io::BufRead;
-use std::borrow::Cow;
-use std::convert::TryInto;
-use std::sync::Arc;
-use rayon::prelude::*;
-
-mod parse;
-mod value;
-mod util;
-mod env;
-
-use value::Value;
-use env::{Rule, Ruleset, Env, Bindings, RuleResult, Operation};
-
-// Main pattern matcher function;
-fn match_and_bind(expr: &Value, rule: &Rule, env: &Env) -> Result> {
- fn go(expr: &Value, cond: &Value, env: &Env, already_bound: &Bindings) -> Result> {
- match (expr, cond) {
- // numbers match themselves
- (Value::Num(a), Value::Num(b)) => if a == b { Ok(Some(HashMap::new())) } else { Ok(None) },
- // handle predicated value - check all predicates, succeed with binding if they match
- (val, Value::Call(x, args)) if x == "#" => {
- let preds = &args[1..];
- let (mut success, mut bindings) = match go(val, &args[0], env, already_bound)? {
- Some(bindings) => (true, bindings),
- None => (false, already_bound.clone())
- };
-
- for pred in preds {
- match pred {
- // "Num" predicate matches successfully if something is a number
- Value::Identifier(i) if i.as_ref() == "Num" => {
- match val {
- Value::Num(_) => (),
- _ => success = false
- }
- },
- // "Ident" does the same for idents
- Value::Identifier(i) if i.as_ref() == "Ident" => {
- match val {
- Value::Identifier(_) => (),
- _ => success = false
- }
- },
- // Invert match success
- Value::Identifier(i) if i.as_ref() == "Not" => {
- success = !success
- },
- Value::Call(head, args) if head.as_ref() == "And" => {
- // Try all patterns it's given, and if any fails then fail the match
- for arg in args.iter() {
- match go(val, arg, env, &bindings)? {
- Some(new_bindings) => bindings.extend(new_bindings),
- None => success = false
- }
- }
- },
- Value::Call(head, args) if head.as_ref() == "Eq" => {
- // Evaluate all arguments and check if they are equal
- let mut compare_against = None;
- for arg in args.iter() {
- let mut evaluated_value = arg.subst(&bindings);
- run_rewrite(&mut evaluated_value, env).context("evaluating Eq predicate")?;
- match compare_against {
- Some(ref x) => if x != &evaluated_value {
- success = false
- },
- None => compare_against = Some(evaluated_value)
- }
- }
- },
- Value::Call(head, args) if head.as_ref() == "Gte" => {
- // Evaluate all arguments and do comparison.
- let mut x = args[0].subst(&bindings);
- let mut y = args[1].subst(&bindings);
- run_rewrite(&mut x, env).context("evaluating Gte predicate")?;
- run_rewrite(&mut y, env).context("evaluating Gte predicate")?;
- success &= x >= y;
- },
- Value::Call(head, args) if head.as_ref() == "Or" => {
- // Tries all patterns it's given and will set the match to successful if *any* of them works
- for arg in args.iter() {
- match go(val, arg, env, &bindings)? {
- Some(new_bindings) => {
- bindings.extend(new_bindings);
- success = true
- },
- None => ()
- }
- }
- },
- _ => bail!("invalid predicate {:?}", pred)
- }
- }
- Ok(match success {
- true => Some(bindings),
- false => None
- })
- },
- (Value::Call(exp_head, exp_args), Value::Call(rule_head, rule_args)) => {
- let mut exp_args = Cow::Borrowed(exp_args);
- // Regardless of any special casing for associativity etc., different heads mean rules can never match
- if exp_head != rule_head { return Ok(None) }
-
- let op = env.get_op(exp_head);
-
- // Copy bindings from the upper-level matching, so that things like "a+(b+a)" work.
- let mut out_bindings = already_bound.clone();
-
- // Special case for associative expressions: split off extra arguments into a new tree
- if op.associative && rule_args.len() < exp_args.len() {
- let exp_args = exp_args.to_mut();
- let rest = exp_args.split_off(rule_args.len() - 1);
- let rem = Value::Call(exp_head.clone(), rest);
- exp_args.push(rem);
- }
- if rule_args.len() != exp_args.len() { return Ok(None) }
-
- // Try and match all "adjacent" arguments to each other
- for (rule_arg, exp_arg) in rule_args.iter().zip(&*exp_args) {
- match go(exp_arg, rule_arg, env, &out_bindings)? {
- Some(x) => out_bindings.extend(x),
- None => return Ok(None)
- }
- }
- Ok(Some(out_bindings))
- },
- // identifier pattern matches anything, unless the identifier has already been bound to something else
- (x, Value::Identifier(a)) => {
- if let Some(b) = already_bound.get(a) {
- if b != x {
- return Ok(None);
- }
- };
- Ok(Some(vec![(a.clone(), x.clone())].into_iter().collect()))
- },
- // anything else doesn't match
- _ => Ok(None)
- }
- }
- // special case at top level of expression - try to match pattern to different subranges of input
- match (expr, &rule.condition) {
- // this only applies to matching one "call" against a "call" pattern (with same head)
- (Value::Call(ehead, eargs), Value::Call(rhead, rargs)) => {
- // and also only to associative operations
- if env.get_op(ehead).associative && eargs.len() > rargs.len() && ehead == rhead {
- // consider all possible subranges of the arguments of the appropriate length
- for range_start in 0..=(eargs.len() - rargs.len()) {
- // extract the arguments & convert into new Value
- let c_args = eargs[range_start..range_start + rargs.len()].iter().cloned().collect();
- let c_call = Value::Call(ehead.clone(), c_args);
- // attempt to match the new subrange against the current rule
- if let Some(r) = match_and_bind(&c_call, rule, env)? {
- // generate new output with result
- let mut new_args = Vec::with_capacity(3);
- // add back extra start items
- if range_start != 0 {
- new_args.push(Value::Call(ehead.clone(), eargs[0..range_start].iter().cloned().collect()))
- }
- new_args.push(r);
- // add back extra end items
- if range_start + rargs.len() != eargs.len() {
- new_args.push(Value::Call(ehead.clone(), eargs[range_start + rargs.len()..eargs.len()].iter().cloned().collect()))
- }
- let new_exp = Value::Call(ehead.clone(), new_args);
- return Ok(Some(new_exp))
- }
- }
- }
- }
- _ => ()
- }
- // substitute bindings from matching into either an intrinsic or the output of the rule
- if let Some(bindings) = go(expr, &rule.condition, env, &HashMap::new())? {
- Ok(Some(match &rule.result {
- RuleResult::Intrinsic(id) => env.intrinsics.get(id).unwrap()(&bindings).with_context(|| format!("applying intrinsic {}", id))?,
- RuleResult::Exp(e) => e.subst(&bindings)
- }))
- } else {
- Ok(None)
- }
-}
-
-// Sort any commutative expressions
-fn canonical_sort(v: &mut Value, env: &Env) -> Result<()> {
- match v {
- Value::Call(head, args) => if env.get_op(head).commutative {
- args.sort();
- },
- _ => ()
- }
- Ok(())
-}
-
-// Associative expression flattening.
-fn flatten_tree(v: &mut Value, env: &Env) -> Result<()> {
- match v {
- Value::Call(head, args) => {
- if env.get_op(head).associative {
- // Not the most efficient algorithm, but does work.
- // Repeatedly find the position of a flatten-able child node, and splice it into the argument list.
- loop {
- let mut move_pos = None;
- for (i, child) in args.iter().enumerate() {
- if let Some(child_head) = child.head() {
- if *head == child_head {
- move_pos = Some(i)
- }
- }
- }
- match move_pos {
- Some(pos) => {
- let removed = std::mem::replace(&mut args[pos], Value::Num(0));
- // We know that removed will be a Call (because its head wasn't None earlier). Unfortunately, rustc does not know this.
- match removed {
- Value::Call(_, removed_child_args) => args.splice(pos..=pos, removed_child_args.into_iter()),
- _ => unreachable!()
- };
- },
- None => break
- }
- }
- }
- // Also do sorting after flattening, to avoid any weirdness with ordering.
- canonical_sort(v, env)?;
- return Ok(())
- },
- _ => return Ok(())
- }
-}
-
-// Applies rewrite rulesets to an expression.
-fn run_rewrite(v: &mut Value, env: &Env) -> Result<()> {
- loop {
- // Compare original and final hash instead of storing a copy of the original value and checking equality
- // Collision probability is negligible and this is substantially faster than storing/comparing copies.
- let original_hash = v.get_hash();
-
- flatten_tree(v, env).context("flattening tree")?;
- // Call expressions can be rewritten using pattern matching rules; identifiers can be substituted for bindings if available
- match v {
- Value::Call(head, args) => {
- let head = head.clone();
-
- // Rewrite sub-expressions using existing environment
- args.par_iter_mut().try_for_each(|arg| run_rewrite(arg, env).with_context(|| format!("rewriting {}", arg.render_to_string(env))))?;
-
- // Try to apply all applicable rules from all rulesets, in sequence
- for ruleset in env.ruleset.iter() {
- if let Some(rules) = ruleset.get(&head) {
- // Within a ruleset, rules are applied backward. This is nicer for users using the program interactively.
- for rule in rules.iter().rev() {
- if let Some(result) = match_and_bind(v, rule, env).with_context(|| format!("applying rule {} -> {:?}", rule.condition.render_to_string(env), rule.result))? {
- *v = result;
- flatten_tree(v, env).context("flattening tree after rule application")?;
- }
- }
- }
- }
- },
- // Substitute in bindings which have been provided
- Value::Identifier(ident) => {
- match env.bindings.get(ident) {
- Some(val) => {
- *v = val.clone();
- },
- None => return Ok(())
- }
- },
- _ => {
- return Ok(())
- }
- }
- if original_hash == v.get_hash() {
- break
- }
- }
- Ok(())
-}
-
-// Utility function for defining intrinsic functions for binary operators.
-// Converts a function which does the actual operation to a function from bindings to a value.
-fn wrap_binop Result + Sync + Send>(op: F) -> Box Result + Sync + Send> {
- Box::new(move |bindings: &Bindings| {
- let a = bindings.get(&InlinableString::from("a")).context("binop missing first argument")?.assert_num("binop first argument")?;
- let b = bindings.get(&InlinableString::from("b")).context("binop missing second argument")?.assert_num("binop second argument")?;
- op(a, b).map(Value::Num)
- })
-}
-
-// Provides a basic environment with operator commutativity/associativity operations and intrinsics.
-fn make_initial_env() -> Env {
- let mut ops = HashMap::new();
- ops.insert(InlinableString::from("+"), Operation { commutative: true, associative: true });
- ops.insert(InlinableString::from("*"), Operation { commutative: true, associative: true });
- ops.insert(InlinableString::from("-"), Operation { commutative: false, associative: false });
- ops.insert(InlinableString::from("/"), Operation { commutative: false, associative: false });
- ops.insert(InlinableString::from("^"), Operation { commutative: false, associative: false });
- ops.insert(InlinableString::from("="), Operation { commutative: false, associative: false });
- ops.insert(InlinableString::from("#"), Operation { commutative: false, associative: true });
- let ops = Arc::new(ops);
- let mut intrinsics = HashMap::new();
- intrinsics.insert(0, wrap_binop(|a, b| a.checked_add(b).context("integer overflow")));
- intrinsics.insert(1, wrap_binop(|a, b| a.checked_sub(b).context("integer overflow")));
- intrinsics.insert(2, wrap_binop(|a, b| a.checked_mul(b).context("integer overflow")));
- intrinsics.insert(3, wrap_binop(|a, b| a.checked_div(b).context("division by zero")));
- intrinsics.insert(4, wrap_binop(|a, b| {
- // The "pow" function takes a usize (machine-sized unsigned integer) and an i128 may not fit into this, so an extra conversion is needed
- Ok(a.pow(b.try_into()?))
- }));
- intrinsics.insert(5, Box::new(|bindings| {
- // Substitute a single, given binding var=value into a target expression
- let var = bindings.get(&InlinableString::from("var")).unwrap();
- let value = bindings.get(&InlinableString::from("value")).unwrap();
- let target = bindings.get(&InlinableString::from("target")).unwrap();
- let name = var.assert_ident("Subst")?;
- let mut new_bindings = HashMap::new();
- new_bindings.insert(name, value.clone());
- Ok(target.subst(&new_bindings))
- }));
- intrinsics.insert(6, wrap_binop(|a, b| a.checked_rem(b).context("division by zero")));
- let intrinsics = Arc::new(intrinsics);
- Env {
- ruleset: vec![],
- ops: ops.clone(),
- intrinsics: intrinsics.clone(),
- bindings: HashMap::new()
- }
-}
-
-const BUILTINS: &str = "
-SetStage[all]
-a#Num + b#Num = Intrinsic[0]
-a#Num - b#Num = Intrinsic[1]
-a#Num * b#Num = Intrinsic[2]
-a#Num / b#Num = Intrinsic[3]
-a#Num ^ b#Num = Intrinsic[4]
-Subst[var=value, target] = Intrinsic[5]
-Mod[a#Num, b#Num] = Intrinsic[6]
-PushRuleset[builtins]
-";
-
-const GENERAL_RULES: &str = "
-SetStage[all]
-(a*b#Num)+(a*c#Num) = (b+c)*a
-Negate[a] = 0 - a
-a^b*a^c = a^(b+c)
-a^0 = 1
-a^1 = a
-(a^b)^c = a^(b*c)
-0*a = 0
-0+a = a
-1*a = a
-x/x = 1
-(n*x)/x = n
-PushRuleset[general_rules]
-";
-
-const NORMALIZATION_RULES: &str = "
-SetStage[norm]
-a/b = a*b^Negate[1]
-a+b#Num*a = (b+1)*a
-a^b#Num#Gte[b, 2] = a*a^(b-1)
-a-c#Num*b = a+Negate[c]*b
-a+a = 2*a
-a*(b+c) = a*b+a*c
-a-b = a+Negate[1]*b
-PushRuleset[normalization]
-";
-
-const DENORMALIZATION_RULES: &str = "
-SetStage[denorm]
-a*a = a^2
-a^b#Num*a = a^(b+1)
-c+a*b#Num#Gte[0, b] = c-a*Negate[b]
-PushRuleset[denormalization]
-";
-
-const DIFFERENTIATION_DEFINITION: &str = "
-SetStage[all]
-D[x, x] = 1
-D[a#Num, x] = 0
-D[f+g, x] = D[f, x] + D[g, x]
-D[f*g, x] = D[f, x] * g + D[g, x] * f
-D[a#Num*f, x] = a * D[f, x]
-PushRuleset[differentiation]
-";
-
-const FACTOR_DEFINITION: &str = "
-SetStage[post_norm]
-Factor[x, a*x+b] = x * (a + Factor[x, b] / x)
-PushRuleset[factor]
-SetStage[pre_denorm]
-Factor[x, a] = a
-PushRuleset[factor_postprocess]
-SetStage[denorm]
-x^n/x = x^(n-1)
-(a*x^n)/x = a*x^(n-1)
-PushRuleset[factor_postpostprocess]
-";
-
-struct ImperativeCtx {
- bindings: Bindings,
- current_ruleset_stage: InlinableString,
- current_ruleset: Ruleset,
- rulesets: HashMap>,
- stages: Vec<(InlinableString, Vec)>,
- base_env: Env
-}
-
-impl ImperativeCtx {
- // Make a new imperative context
- // Stages are currently hardcoded, as adding a way to manage them would add lots of complexity
- // for limited benefit
- fn init() -> Self {
- let stages = [
- "pre_norm",
- "norm",
- "post_norm",
- "pre_denorm",
- "denorm",
- "post_denorm"
- ].iter().map(|name| (InlinableString::from(*name), vec![])).collect();
- ImperativeCtx {
- bindings: HashMap::new(),
- current_ruleset_stage: InlinableString::from("post_norm"),
- current_ruleset: HashMap::new(),
- rulesets: HashMap::new(),
- stages,
- base_env: make_initial_env()
- }
- }
-
- // Insert a rule into the current ruleset; handles switching out the result for a relevant intrinsic use, generating possible reorderings, and inserting into the lookup map.
- fn insert_rule(&mut self, condition: &Value, result_val: Value) -> Result<()> {
- let result = match result_val {
- Value::Call(head, args) if head == "Intrinsic" => RuleResult::Intrinsic(args[0].assert_num("Intrinsic ID")? as usize),
- _ => RuleResult::Exp(result_val)
- };
- for rearrangement in condition.pattern_reorderings(&self.base_env).into_iter() {
- let rule = Rule {
- condition: rearrangement,
- result: result.clone()
- };
- self.current_ruleset.entry(condition.head().unwrap()).or_insert_with(Vec::new).push(rule);
- }
- Ok(())
- }
-
- // Run a single statement (roughly, a line of user input) on the current context
- fn eval_statement(&mut self, mut stmt: Value) -> Result> {
- match stmt {
- // = sets a binding or generates a new rule.
- Value::Call(head, args) if head.as_ref() == "=" => {
- match &args[0] {
- // Create a binding if the LHS (left hand side) is just an identifier
- Value::Identifier(id) => {
- let rhs = self.eval_statement(args[1].clone())?;
- if let Some(val) = rhs.clone() {
- self.bindings.insert(id.clone(), val);
- }
- Ok(rhs)
- },
- // If the LHS is a call, then a rule should be created instead.
- Value::Call(_head, _args) => {
- let rhs = self.eval_statement(args[1].clone())?;
- if let Some(val) = rhs.clone() {
- self.insert_rule(&args[0], val)?;
- }
- Ok(rhs)
- },
- // Rebinding numbers can only bring confusion, so it is not allowed.
- // They also do not have a head, and so cannot be inserted into the ruleset anyway.
- Value::Num(_) => bail!("You cannot rebind numbers")
- }
- },
- // SetStage[] calls set the stage the current ruleset will be applied at
- Value::Call(head, args) if head.as_ref() == "SetStage" => {
- let stage = args[0].assert_ident("SetStage requires an identifier for stage")?;
- if stage != "all" && None == self.stages.iter().position(|s| s.0 == stage) {
- bail!("No such stage {}", stage);
- }
- self.current_ruleset_stage = stage;
- Ok(None)
- },
- // Move the current ruleset from the "buffer" into the actual list of rules to be applied at each stage
- Value::Call(head, args) if head.as_ref() == "PushRuleset" => {
- let name = args[0].assert_ident("PushRuleset requires an identifier for ruleset name")?;
- // Get ruleset and set the current one to empty
- let ruleset = std::mem::replace(&mut self.current_ruleset, HashMap::new());
- // Push ruleset to stages it specifies
- for (stage_name, stage_rulesets) in self.stages.iter_mut() {
- if *stage_name == self.current_ruleset_stage || self.current_ruleset_stage == "all" {
- stage_rulesets.push(name.clone());
- }
- }
- // Insert actual ruleset data under its name
- self.rulesets.insert(name, Arc::new(ruleset));
- Ok(None)
- },
- // Anything not special should just be repeatedly run through each rewrite stage.
- _ => {
- let env = self.base_env.with_bindings(&self.bindings);
- for (stage_name, stage_rulesets) in self.stages.iter() {
- // Add relevant rulesets to a new environment for this stage
- let mut env = env.clone();
- for ruleset in stage_rulesets.iter() {
- env = env.with_ruleset(self.rulesets[ruleset].clone());
- }
- // Also add the current ruleset if applicable
- if self.current_ruleset_stage == *stage_name || self.current_ruleset_stage == "all" {
- env = env.with_ruleset(Arc::new(self.current_ruleset.clone()));
- }
- run_rewrite(&mut stmt, &env).with_context(|| format!("failed in {} stage", stage_name))?;
- // If a ruleset is only meant to be applied in one particular stage, it shouldn't have any later stages applied to it,
- // or the transformation it's meant to do may be undone
- if self.current_ruleset_stage == *stage_name {
- break
- }
- }
- Ok(Some(stmt))
- }
- }
- }
-
- // Evaluate an entire "program" (multiple statements delineated by ; or newlines)
- fn eval_program(&mut self, program: &str) -> Result> {
- let mut tokens = parse::lex(program)?;
- let mut last_value = None;
- loop {
- // Split at the next break token
- let remaining_tokens = tokens.iter().position(|x| *x == parse::Token::Break).map(|ix| tokens.split_off(ix + 1));
- // Trim EOF/break tokens
- match tokens[tokens.len() - 1] {
- parse::Token::Break | parse::Token::EOF => tokens.truncate(tokens.len() - 1),
- _ => ()
- };
- // If the statement/line isn't blank, readd EOF for the parser, parse into an AST then Value, and evaluate the statement
- if tokens.len() > 0 {
- tokens.push(parse::Token::EOF);
- let value = Value::from_ast(parse::parse(tokens)?);
- last_value = self.eval_statement(value)?;
- }
- // If there was no break after the current position, this is now done. Otherwise, move onto the new remaining tokens.
- match remaining_tokens {
- Some(t) => { tokens = t },
- None => break
- }
- }
- Ok(last_value)
- }
-}
+use anyhow::Result;
fn main() -> Result<()> {
let mut ctx = ImperativeCtx::init();
@@ -572,62 +20,4 @@ fn main() -> Result<()> {
}
}
Ok(())
-}
-
-#[cfg(test)]
-mod test {
- use crate::{ImperativeCtx, BUILTINS, GENERAL_RULES, NORMALIZATION_RULES, DENORMALIZATION_RULES, DIFFERENTIATION_DEFINITION, FACTOR_DEFINITION};
-
- #[test]
- fn end_to_end_tests() {
- let mut ctx = ImperativeCtx::init();
- ctx.eval_program(BUILTINS).unwrap();
- ctx.eval_program(GENERAL_RULES).unwrap();
- ctx.eval_program(FACTOR_DEFINITION).unwrap();
- ctx.eval_program(DENORMALIZATION_RULES).unwrap();
- ctx.eval_program(NORMALIZATION_RULES).unwrap();
- ctx.eval_program(DIFFERENTIATION_DEFINITION).unwrap();
- let test_cases = [
- ("Factor[x, x*3+x^2]", "(3+x)*x"),
- ("x^a/x^(a+1)", "x^Negate[1]"),
- ("Negate[a+b]", "Negate[1]*b-a"),
- ("Subst[x=4, x+4+4+4+4]", "20"),
- ("(a+b)*(c+d)*(e+f)", "a*c*e+a*c*f+a*d*e+a*d*f+b*c*e+b*c*f+b*d*e+b*d*f"),
- ("(12+55)^3-75+16/(2*2)+5+3*4", "300709"),
- ("D[3*x^3 + 6*x, x] ", "6+9*x^2"),
- ("Fib[n] = Fib[n-1] + Fib[n-2]
- Fib[0] = 0
- Fib[1] = 1
- Fib[6]", "8"),
- ("Subst[b=a, b+a]", "2*a"),
- ("a = 7
- b = Negate[4]
- a + b", "3"),
- ("IsEven[x] = 0
- IsEven[x#Eq[Mod[x, 2], 0]] = 1
- IsEven[3] - IsEven[4]", "Negate[1]"),
- ("(a+b+c)^2", "2*a*b+2*a*c+2*b*c+a^2+b^2+c^2"),
- ("(x+2)^7", "128+2*x^6+12*x^5+12*x^6+16*x^3+16*x^5+24*x^4+24*x^5+32*x^2+32*x^3+32*x^5+128*x^2+256*x^4+448*x+512*x^2+512*x^3+x^7")
- ];
- for (input, expected_result) in test_cases {
- let lhs = ctx.eval_program(input).unwrap();
- let lhs = lhs.as_ref().unwrap().render_to_string(&ctx.base_env);
- println!("{} evaluated to {}; expected {}", input, lhs, expected_result);
- assert_eq!(lhs, expected_result);
- }
-
- let error_cases = [
- ("1/0")
- ];
-
- for error_case in error_cases {
- if let Err(e) = ctx.eval_program(error_case) {
- println!("{} produced error {:?}", error_case, e);
- } else {
- panic!("should have errored: {}", error_case)
- }
- }
-
- println!("All tests passed.")
- }
}
\ No newline at end of file