beta 2009.06.07 13:11

1 files changed, 55 insertions, 0 deletions

diff --git a/tex/context/base/meta-fun.lua b/tex/context/base/meta-fun.lua
new file mode 100644
index 000000000..84d4afb19
--- /dev/null
+++ b/tex/context/base/meta-fun.lua
@@ -0,0 +1,55 @@
+if not modules then modules = { } end modules ['meta-fun'] = {
+    version   = 1.001,
+    comment   = "companion to meta-fun.tex",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files",
+}
+
+-- very experimental, actually a joke ... see metafun manual for usage
+
+local format, loadstring, type = string.format, loadstring, type
+local texwrite = tex.write
+
+metafun = metafun or { }
+
+function metafun.topath(t,connector)
+    tex.write("(")
+    if #t > 0 then
+        for i=1,#t do
+            if i > 1 then
+                texwrite(connector or "..")
+            end
+            local ti = t[i]
+            if type(ti) == "string" then
+                texwrite(ti)
+            else
+                texwrite(format("(%s,%s)",ti.x or ti[1] or 0,ti.y or ti[2] or 0))
+            end
+        end
+    else
+        texwrite("origin")
+    end
+    texwrite(")")
+end
+
+function metafun.interpolate(f,b,e,s,c)
+    local done = false
+    tex.write("(")
+    for i=b,e,(e-b)/s do
+        local d = loadstring(format("return function(x) return %s end",f))
+        if d then
+            d = d()
+            if done then
+                texwrite(c or "...")
+            else
+                done = true
+            end
+            texwrite(format("(%s,%s)",i,d(i)))
+        end
+    end
+    if not done then
+        texwrite("origin")
+    end
+    texwrite(")")
+end