Support float(<str>) and float(<bytes>)

Cargo.lock

@@ -402,6 +402,26 @@ name = "lazy_static"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "lexical"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lexical-core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "lexical-core"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ryu 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "stackvector 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "static_assertions 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.42"
@@ -709,6 +729,7 @@ dependencies = [
  "byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "caseless 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lexical 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-bigint 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-complex 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -754,7 +775,7 @@ dependencies = [
 
 [[package]]
 name = "ryu"
-version = "0.2.5"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -783,7 +804,7 @@ version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "itoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "ryu 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ryu 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.66 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -808,6 +829,19 @@ name = "sourcefile"
 version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "stackvector"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "static_assertions"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "statrs"
 version = "0.10.0"
@@ -1188,6 +1222,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum lalrpop-snap 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)" = "60013fd6be14317d43f47658b1440956a9ca48a9ed0257e0e0a59aac13e43a1f"
 "checksum lalrpop-util 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)" = "60c6c48ba857cd700673ce88907cadcdd7e2cd7783ed02378537c5ffd4f6460c"
 "checksum lazy_static 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e6412c5e2ad9584b0b8e979393122026cdd6d2a80b933f890dcd694ddbe73739"
+"checksum lexical 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e4fac65df7e751b57bb3a334c346239cb4ce2601907d698726ceeb82a54ba4ef"
+"checksum lexical-core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "025babf624c0c2b4bed1373efd684d5d0b2eecd61138d26ec3eec77bf0f2e33d"
 "checksum libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)" = "b685088df2b950fccadf07a7187c8ef846a959c142338a48f9dc0b94517eb5f1"
 "checksum log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e19e8d5c34a3e0e2223db8e060f9e8264aeeb5c5fc64a4ee9965c062211c024b"
 "checksum log 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6fddaa003a65722a7fb9e26b0ce95921fe4ba590542ced664d8ce2fa26f9f3ac"
@@ -1224,7 +1260,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8f1ac0f60d675cc6cf13a20ec076568254472551051ad5dd050364d70671bf6b"
 "checksum rustc-demangle 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "bcfe5b13211b4d78e5c2cadfebd7769197d95c639c35a50057eb4c05de811395"
 "checksum rustyline 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6010155119d53aac4f5b987cb8f6ea913d0d64d9b237da36f8f96a90cb3f5385"
-"checksum ryu 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e7c066b8e2923f05d4718a06d2622f189ff362bc642bfade6c6629f0440f3827"
+"checksum ryu 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "eb9e9b8cde282a9fe6a42dd4681319bfb63f121b8a8ee9439c6f4107e58a46f7"
 "checksum scoped_threadpool 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "1d51f5df5af43ab3f1360b429fa5e0152ac5ce8c0bd6485cae490332e96846a8"
 "checksum serde 1.0.66 (registry+https://github.com/rust-lang/crates.io-index)" = "e9a2d9a9ac5120e0f768801ca2b58ad6eec929dc9d1d616c162f208869c2ce95"
 "checksum serde_derive 1.0.66 (registry+https://github.com/rust-lang/crates.io-index)" = "0a90213fa7e0f5eac3f7afe2d5ff6b088af515052cc7303bd68c7e3b91a3fb79"
@@ -1232,6 +1268,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum sha2 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9eb6be24e4c23a84d7184280d2722f7f2731fcdd4a9d886efbfe4413e4847ea0"
 "checksum siphasher 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "0df90a788073e8d0235a67e50441d47db7c8ad9debd91cbf43736a2a92d36537"
 "checksum sourcefile 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "4bf77cb82ba8453b42b6ae1d692e4cdc92f9a47beaf89a847c8be83f4e328ad3"
+"checksum stackvector 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c049c77bf85fbc036484c97b008276d539d9ebff9dfbde37b632ebcd5b8746b6"
+"checksum static_assertions 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "c19be23126415861cb3a23e501d34a708f7f9b2183c5252d690941c2e69199d5"
 "checksum statrs 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "10102ac8d55e35db2b3fafc26f81ba8647da2e15879ab686a67e6d19af2685e8"
 "checksum string_cache 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "25d70109977172b127fe834e5449e5ab1740b9ba49fa18a2020f509174f25423"
 "checksum string_cache_codegen 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "35293b05cf1494e8ddd042a7df6756bf18d07f42d234f32e71dce8a7aabb0191"

tests/snippets/floats.py

@@ -1,3 +1,23 @@
+import math
+
+def assert_raises(expr, exc_type):
+    """
+    Helper function to assert `expr` raises an exception of type `exc_type`
+    Args:
+        expr: Callable
+        exec_type: Exception
+    Returns:
+        None
+    Raises:
+        Assertion error on failure
+    """
+    try:
+        expr(None)
+    except exc_type:
+        assert True
+    else:
+        assert False
+
 1 + 1.1
 
 a = 1.2
@@ -39,3 +59,25 @@ try:
     assert a >= 'a'
 except TypeError:
     pass
+
+assert math.isnan(float('nan'))
+assert math.isnan(float('NaN'))
+assert math.isnan(float('+NaN'))
+assert math.isnan(float('-NaN'))
+
+assert math.isinf(float('inf'))
+assert math.isinf(float('Inf'))
+assert math.isinf(float('+Inf'))
+assert math.isinf(float('-Inf'))
+
+assert float('+Inf') > 0
+assert float('-Inf') < 0
+
+assert float('3.14') == 3.14
+assert float('2.99e-23') == 2.99e-23
+
+assert float(b'3.14') == 3.14
+assert float(b'2.99e-23') == 2.99e-23
+
+assert_raises(lambda _: float('foo'), ValueError)
+assert_raises(lambda _: float(2**10000), OverflowError)

vm/Cargo.toml

@@ -21,3 +21,4 @@ statrs = "0.10.0"
 caseless = "0.2.1"
 unicode-segmentation = "1.2.1"
 lazy_static = "^1.0.1"
+lexical = "2.0.0"

vm/src/lib.rs

@@ -9,6 +9,7 @@
 extern crate bitflags;
 #[macro_use]
 extern crate lazy_static;
+extern crate lexical;
 #[macro_use]
 extern crate log;
 // extern crate env_logger;

vm/src/obj/objfloat.rs

@@ -2,7 +2,9 @@ use super::super::pyobject::{
     PyContext, PyFuncArgs, PyObjectPayload, PyObjectRef, PyResult, TypeProtocol,
 };
 use super::super::vm::VirtualMachine;
+use super::objbytes;
 use super::objint;
+use super::objstr;
 use super::objtype;
 use num_bigint::ToBigInt;
 use num_traits::ToPrimitive;
@@ -23,9 +25,35 @@ fn float_init(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     let val = if objtype::isinstance(arg, &vm.ctx.float_type()) {
         get_value(arg)
     } else if objtype::isinstance(arg, &vm.ctx.int_type()) {
-        objint::get_value(arg).to_f64().unwrap()
+        match objint::get_value(arg).to_f64() {
+            Some(f) => f,
+            None => {
+                return Err(vm.new_overflow_error("int too large to convert to float".to_string()));
+            }
+        }
+    } else if objtype::isinstance(arg, &vm.ctx.str_type()) {
+        match lexical::try_parse(objstr::get_value(arg)) {
+            Ok(f) => f,
+            Err(_) => {
+                let arg_repr = vm.to_pystr(arg)?;
+                return Err(
+                    vm.new_value_error(format!("could not convert string to float: {}", arg_repr))
+                );
+            }
+        }
+    } else if objtype::isinstance(arg, &vm.ctx.bytes_type()) {
+        match lexical::try_parse(objbytes::get_value(arg).as_slice()) {
+            Ok(f) => f,
+            Err(_) => {
+                let arg_repr = vm.to_pystr(arg)?;
+                return Err(
+                    vm.new_value_error(format!("could not convert string to float: {}", arg_repr))
+                );
+            }
+        }
     } else {
-        return Err(vm.new_type_error("Cannot construct int".to_string()));
+        let type_name = objtype::get_type_name(&arg.typ());
+        return Err(vm.new_type_error(format!("can't convert {} to float", type_name)));
     };
     set_value(zelf, val);
     Ok(vm.get_none())