Define monomial constructor (#328)

* Define monomial constructor

* Bump TP to v0.4.2

* Drop Julia v1.6

Author: blegat

.github/workflows/ci.yml

@@ -17,9 +17,6 @@ jobs:
           - version: '1'
             os: ubuntu-latest
             arch: x64
-          - version: '1.6'
-            os: ubuntu-latest
-            arch: x64
           - version: '1.10'
             os: ubuntu-latest
             arch: x64

Project.toml

@@ -14,4 +14,4 @@ MutableArithmetics = "d8a4904e-b15c-11e9-3269-09a3773c0cb0"
 ChainRulesCore = "1"
 DataStructures = "0.19"
 MutableArithmetics = "0.3, 1"
-julia = "1.6"
+julia = "1.10"

src/gcd.jl

@@ -261,14 +261,8 @@ function deflation(p::AbstractPolynomialLike)
     shift_defl = shift_deflation.(p, variables(p))
     shift = getindex.(shift_defl, 1)
     defl = getindex.(shift_defl, 2)
-    s = prod(
-        variables(p) .^ shift;
-        init = constant_monomial(p),
-    )::monomial_type(p)
-    d = prod(
-        variables(p) .^ defl;
-        init = constant_monomial(p),
-    )::monomial_type(p)
+    s = monomial(variables(p), shift)
+    d = monomial(variables(p), defl)
     return s, d
 end
 

src/term.jl

@@ -151,6 +151,17 @@ Returns the monomial of the term `t`.
 ### Examples
 
 Calling `monomial` on ``4x^2y`` should return ``x^2y``.
+
+    monomial(variables, exponents)
+
+Returns the monomial corresponding to `prod(variables .^ exponents)`
+
+### Examples
+
+In order to create `x^2 * y`,
+
+* with DynamicPolynomials, use `monomial([x, y], [2, 1])`,
+* with TypedPolynomials, use `monomial((x, y), (2, 1))`.
 """
 function monomial end
 monomial(t::AbstractTerm) = t.monomial # by convention, the field should be `monomial`.

test/Project.toml

@@ -11,4 +11,4 @@ TypedPolynomials = "afbbf031-7a57-5f58-a1b9-b774a0fad08d"
 
 [compat]
 DynamicPolynomials = "0.6"
-TypedPolynomials = "0.4"
+TypedPolynomials = "0.4.2"