Update to add @cash and @stock macros (#15)

* Update to add @cash and @stock macros * Change README master->main
JuliaFinance · Jul 1, 2020 · 23206aa · 23206aa
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diff --git a/Project.toml b/Project.toml
@@ -4,7 +4,7 @@ keywords = ["Finance", "Asset"]
 license = "MIT"
 desc = "Financial assets"
 authors = ["Eric Forgy <[email protected]>", "ScottPJones <[email protected]>"]
-version = "0.8.0"
+version = "0.9.0"
 
 [deps]
 Currencies = "0fd90b74-7c1f-579e-9252-02cd883047b9"
@@ -13,7 +13,7 @@ Instruments = "2a4f3d17-849a-48a1-809e-d780c70a95a0"
 
 [compat]
 Currencies = ">= 0.17"
-Instruments = ">= 0.7"
+Instruments = ">= 0.8"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

diff --git a/README.md b/README.md
@@ -1,26 +1,10 @@
-[pkg-url]: https://github.com/JuliaFinance/Assets.jl.git
-
-[julia-url]:    https://github.com/JuliaLang/Julia
-[julia-release]:https://img.shields.io/github/release/JuliaLang/julia.svg
-
-[release]:      https://img.shields.io/github/release/JuliaFinance/Assets.jl.svg
-[release-date]: https://img.shields.io/github/release-date/JuliaFinance/Assets.jl.svg
-
-[license-img]:  http://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat
-[license-url]:  LICENSE.md
 [travis-url]:   https://travis-ci.com/JuliaFinance/Assets.jl
-[travis-s-img]: https://travis-ci.com/JuliaFinance/Assets.jl.svg
-[travis-m-img]: https://travis-ci.com/JuliaFinance/Assets.jl.svg?branch=main
-
-[contrib]:    https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat
+[travis-img]: https://travis-ci.com/JuliaFinance/Assets.jl.svg
 
 [codecov-url]:  https://codecov.io/gh/JuliaFinance/Assets.jl
-[codecov-img]:  https://codecov.io/gh/JuliaFinance/Assets.jl/branch/master/graph/badge.svg
+[codecov-img]:  https://codecov.io/gh/JuliaFinance/Assets.jl/branch/main/graph/badge.svg
 
-| **Julia Version** | **Unit Tests** | **Coverage** |
-|:------------------:|:---------------------:|:---------------------:|
-| [![][julia-release]][julia-url] | [![][travis-s-img]][travis-url] | [![][codecov-img]][codecov-url]
-| Julia Latest | [![][travis-m-img]][travis-url] | [![][codecov-img]][codecov-url]
+[![][travis-img]][travis-url] [![][codecov-img]][codecov-url]
 
 # Assets
 
@@ -35,12 +19,14 @@ It also provides a specialized `Position` for `Cash` that uses the currency's mi
 
 When a currency is thought of as a financial instrument (as opposed to a mere label), we choose to refer to it as "Cash" as it would appear in a balance sheet. This package implements the `Cash` instrument with parameter `S` being the 3-character ISO 4217 alpha label of the currency as a `Symbol` and an integer `N` representing the number of decimal places in the currency (typically 0, 2 or 3).
 
-Short constants are set up, matching the ISO 4217 names, so that you can use `USD` instead of `Cash{:USD,2}`.
+The @cash macro will set up short constants, matching the ISO 4217 names, so that you can use `USD` instead of `Cash{:USD,2}`.
+
+One can also use the `cash` string macro, i.e. `cash"GBP"`, to refer to a particular Cash type.
 
 For example:
 
 ```julia
-julia> using Assets: JPY, USD, JOD
+julia> @cash JPY, USD, JOD
 
 julia> JPY
 Cash{:JPY,0}
@@ -63,7 +49,7 @@ Although `Cash` is a singleton type, other financial instruments may contain var
 A `Position` represents an amount of ownership of a financial instrument. For example, Microsoft stock
 
 ```julia
-const MSFT = stock(:MSFT,:USD)
+const MSFT = stock(:MSFT,USD)
 ```
 is a financial instrument. A position could be 1,000 shares of `MSFT` and can be represented in one of two ways:
 
@@ -79,6 +65,11 @@ julia> 1000MSFT
 1000MSFT
 ```
 
+The `stock` string macro can also be used, for example:
+`stock"MSFT"`
+or
+`stock"GSK"gbp` (to indicate a stock, GlaxoSmithKline, denominated in British Pounds).
+
 Similarly, cash positions can be constructed as
 
 ```julia

diff --git a/src/Assets.jl b/src/Assets.jl
@@ -19,7 +19,8 @@ module Assets
 using Currencies, FixedPointDecimals, Instruments
 import Currencies: symbol, currency, unit, code, name
 
-export Cash, Stock, cash, stock, @cash_str, @stock_str
+export Cash, cash, @cash_str, @cash
+export Stock, stock, @stock_str, @stock
 
 """
 `Cash` is an implementation of `Instrument` represented by a singleton type,
@@ -45,39 +46,54 @@ name(::Type{<:Cash{S}}) where {S} = name(S)
 currency(::Type{<:Cash{S}}) where {S} = currency(S)
 
 macro cash_str(str)
-    :( cash(Symbol($(esc(str)))) )
+    :( cash(Symbol($(esc(uppercase(str))))) )
 end
 
-function Position{Cash{C,N}}(a) where {C,N}
+macro cash(syms)
+    args = syms isa Expr ? syms.args : [syms]
+    for nam in args
+        lownam = Symbol(lowercase(string(nam)))
+        Base.eval(__module__, :( const $nam = cash($(QuoteNode(nam))) ) )
+        Base.eval(__module__, :( const $lownam = $nam() ) )
+    end
+end
+
+function Position{S}(amt) where {C,N,S<:Cash{C,N}}
     T = FixedDecimal{Int,N}
-    Position{Cash{C,N},T}(T(a))
+    Position{S,T}(T(amt))
 end
 
 """
 `Stock` is an implementation of a simple `Instrument` represented by a singleton type
-with a stock symbol and currency, e.g. `Stock{:MSFT,:USD}`.
+with a stock symbol and currency, e.g. `Stock{:MSFT,ccy"USD"}`.
 The currency can be omitted and it will default to USD, e.g. `Stock(:MSFT)`.
 """
-struct Stock{S,C} <: Instrument{S,C}
-    Stock(sym::Symbol, ccy::Symbol=:USD) = new{sym,currency(ccy)}()
-    Stock(sym::Symbol, ::Type{T}) where {T<:Currency} = new{sym,T}()
+struct Stock{S,C} <: Instrument{S,Currency}
+    Stock(sym::Symbol, ccy::Type{<:Currency}=Currency(:USD)) = new{sym,currency(ccy)}()
+    Stock(sym::Symbol, pos::Type{<:Cash}) = new{sym,currency(pos)}()
 end
+stock(sym::Symbol, ccy::Type{<:Currency}=Currency(:USD)) = typeof(Stock(sym, currency(ccy)))
+stock(sym::Symbol, pos::Type{<:Cash}) = typeof(Stock(sym, currency(pos)))
 
-"""
-Return the singleton type for a particular general stock, given it's symbol.
-Defaults to USD for the currency
-"""
-stock(sym::Symbol, ccy::Symbol=:USD) = Stock{sym,currency(ccy)}
-stock(sym::Symbol, ::Type{T}) where {T<:Currency} = Stock{sym,T}
+symbol(::Type{Stock{S,C}}) where {S,C} = S
+currency(::Type{Stock{S,C}}) where {S,C} = C
+
+macro stock_str(str, ccy="USD")
+    :( stock(Symbol($(esc(str))), $(esc(currency(Symbol(uppercase(ccy))))) ) )
+end
 
-macro stock_str(str,ccy="USD")
-    :( stock(Symbol($(esc(str))),Symbol($(esc(ccy)))) )
+macro stock(syms)
+    args = syms isa Expr ? syms.args : [syms]
+    for nam in args
+        lownam = Symbol(lowercase(string(nam)))
+        Base.eval(__module__, :( const $nam = stock($(QuoteNode(nam))) ) )
+        Base.eval(__module__, :( const $lownam = $nam() ) )
+    end
 end
 
-# Set up short names for all of the currencies (as Cash instrument types).
-# This is really done as a convenience
-for (s,(ccy,u,c,n)) in Currencies.allpairs()
-    @eval const $s = cash($ccy)
+function Position{S}(amt) where {S<:Stock}
+    T = FixedDecimal{Int,4}
+    Position{S,T}(T(a))
 end
 
 end # module Assets
diff --git a/test/runtests.jl b/test/runtests.jl
@@ -1,8 +1,8 @@
 using Assets, Currencies, Instruments, FixedPointDecimals
-
-using Assets: USD, EUR, JPY, JOD, CNY
 using Currencies: currency, symbol, unit, code, name
 
+@cash USD, EUR, JPY, JOD, CNY
+
 using Test
 
 # Check that some basic currencies have been loaded correctly
@@ -25,7 +25,7 @@ end
 @testset "All currencies" begin
     for sym in Currencies.allsymbols()
         ccy = Currency{sym}()
-        ct = Base.eval(Assets, sym)
+        ct = cash(sym)
         @test ct == cash(typeof(ccy))
         @test ct == cash(sym)
         @test currency(ct) == typeof(ccy)