Rename cond math (#2807)

* Simplifies 'if' to work on the available scope rather than a stream

* Rename initializer/math for better readability

* Fix description

* fmt

crates/nu-cli/src/commands/if_.rs

@@ -26,7 +26,7 @@ impl WholeStreamCommand for If {
         Signature::build("if")
             .required(
                 "condition",
-                SyntaxShape::Math,
+                SyntaxShape::MathExpression,
                 "the condition that must match",
             )
             .required(

crates/nu-cli/src/commands/keep/until.rs

@@ -18,7 +18,7 @@ impl WholeStreamCommand for SubCommand {
         Signature::build("keep until")
             .required(
                 "condition",
-                SyntaxShape::Math,
+                SyntaxShape::RowCondition,
                 "The condition that must be met to stop keeping rows",
             )
             .filter()

crates/nu-cli/src/commands/keep/while_.rs

@@ -17,7 +17,7 @@ impl WholeStreamCommand for SubCommand {
         Signature::build("keep while")
             .required(
                 "condition",
-                SyntaxShape::Math,
+                SyntaxShape::RowCondition,
                 "The condition that must be met to keep rows",
             )
             .filter()

crates/nu-cli/src/commands/set.rs

@@ -29,7 +29,7 @@ impl WholeStreamCommand for Set {
             .required("equals", SyntaxShape::String, "the equals sign")
             .required(
                 "expr",
-                SyntaxShape::Initializer,
+                SyntaxShape::MathExpression,
                 "the value to set the variable to",
             )
     }

crates/nu-cli/src/commands/set_env.rs

@@ -33,7 +33,7 @@ impl WholeStreamCommand for SetEnv {
             .required("equals", SyntaxShape::String, "the equals sign")
             .required(
                 "expr",
-                SyntaxShape::Initializer,
+                SyntaxShape::MathExpression,
                 "the value to set the environment variable to",
             )
     }

crates/nu-cli/src/commands/skip/until.rs

@@ -17,7 +17,7 @@ impl WholeStreamCommand for SubCommand {
         Signature::build("skip until")
             .required(
                 "condition",
-                SyntaxShape::Math,
+                SyntaxShape::RowCondition,
                 "The condition that must be met to stop skipping",
             )
             .filter()

crates/nu-cli/src/commands/skip/while_.rs

@@ -17,7 +17,7 @@ impl WholeStreamCommand for SubCommand {
         Signature::build("skip while")
             .required(
                 "condition",
-                SyntaxShape::Math,
+                SyntaxShape::RowCondition,
                 "The condition that must be met to continue skipping",
             )
             .filter()

crates/nu-cli/src/commands/where_.rs

@@ -22,7 +22,7 @@ impl WholeStreamCommand for Where {
     fn signature(&self) -> Signature {
         Signature::build("where").required(
             "condition",
-            SyntaxShape::Math,
+            SyntaxShape::RowCondition,
             "the condition that must match",
         )
     }